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Oric-1 Manual - Defence Force

1. MAIN PROGRAM Hill HEU BU T T T IT Ti J LIP n M n 11 d Yd L di Ji i 5010 5020 5030 5040 5050 5060 5070 5080 5090 5100 5110 5120 5130 5140 5150 5160 5170 5180 5190 5200 5210 Chapter 12 Better Basic FOR INCR 31 TO 3 STEP 2 HIRES PRINT STEP INCR INK INCR 6 1 FOR COUNT 0 TO SIZE STEP INCR CURSET 180 COUNT IO 3 DRAW COUNT SIZE COUNT 1 CURSET 20 COUNT 10 3 DRAW COUNT SIZE COUNT 1 CURSET COUNT 20 170 3 DRAW SIZE COUNT COUNT 1 CURSET 20 COUNT 10 3 DRAW SIZE COUNT COUNT 1 NEXT COUNT WAIT 100 NEXT INCR PRINT PRESS ANY KEY TO STOP WAIT 500 UNTIL KEYS lt gt RETURN Structured programming does have its drawbacks and you will have to decide when it is too wasteful on memory Some people keep a master copy of a program separately complete with REM statements and explanations of how it works while the working copies have the REMs and indenting removed It is always useful to be able to refer to the master copy if you need to alter the program at a later date Advantages Of a structured approach 1 The flow of control is easy to follow 2 The structures will fit into neat separate modules 3 The numbers of mistakes will be reduced and those errors that do creep in are easily eliminated 4 The ideas inherent in this approach make learning other languages and their applic
2. Y mj X d od di di di Wd 4 Wd dod Wu d 4 di Chapter 3 Programming in BASIC REPEAT UNTIL If you wish to repeat a series of instructions a certain number of times then it is easy to use a FOR NEXT loop This will be repeated the number of times that is set up in the first line e g FORN ITOS5 will loop five times If you wish to loop until a certain condition is true it is difficult to know what value to put in the loop counter REPEAT allows you to loop any number of times and tests at the end of each loop to check if the condition is met in the UNTIL line This short program demonstrates this 10 REPEAT 20 D D INT RND 1 6 1 30 PRINT D 40 UNTIL D gt 20 50 STOP This simulates a situation where a die is being thrown and will continue to be thrown until the total exceeds 20 It would not be possible to know the number of loops before the condition in line 40 is met so a FOR NEXT loop cannot be used It would be possible to imitate this action using a GOTO statement IF the condition was not met but the structure of the program would not be clear on reading the listing so REPEAT should be used where possible Note that as with FOR NEXT the condition is tested at the end so the loop is always negotiated at least once gt gt F gt F gt gt gt K gt K OK gt Before we go on to more Interesting areas such as the pictures and sound there is one last thing you c
3. 99TOISTEP 1 140 CIRCLE N l 150 PATTERN 100 N 160 NEXT N s sie sie gt SK SK E POINTS If you want to know if any particular pixel on the screen is in fore ground or background colour e g if there is a space invader at the centre of the screen then POINT is the command you need To see how it works try this in direct mode Type HIRES Now type CURSET 0 0 0 cursor set at position 0 0 in background colour Now type TEXT next PRINT POINT 0 0 As 0 0 is set to background you will get 0 printed Type HIRES This time type CURSET 0 0 1 cursor set at position 0 0 in foreground colour Now TEXT then PRINT POINT 0 0 This time you should get 1 as the pixel is set to foreground 42 W H I um JP dm ar p jp JP dra diii 4 a 1 i di 4 l V d ud b d d d di 1 Chapter 4 Colour and Graphics FILL This is a useful command that can fill an area of so many rows with a value and so many character cells with a value between 0 and 127 There are 200 rows 40 cells per row The value produces colours and patterns according to the attributes see appendix and chapter 7 for details Here is a short program to show you the fine detail that ORIC can achieve 5 HIRES 10 FORN Otol99 20 X RND 8 16 30 FILLLI X 40 NEXTN Line 20 chooses background colours at random from line 0 top to line 199 bottom Experiment to find what
4. following THEN If the expres sion is false then these instruc tions are ignored and program executes instructions following ELSE ELSE may be omitted 139 ORIC Manual INK INPUT INT KEY LEFT LEN LET LIST LLIST LN LOG LORES N MID MUSIC NEW ON GOSUB ON GOTO PAPER 140 Changes foreground colour of INKN whole screen N is an integer 7 Stops program execution and INPUT N waits for an input before INPUT Age continuing Returns largest integer less than or X INT Y equal to value in brackets 0 5 Strobes keyboard X KEY Continues execution whether or not a key has been pressed X contains value of any key pressed Returns the left portion of a L LEFT string N characters in length A N Returns the length of a string A LEN N Assigns value to a variable LET A 4 Optional Lists specified lines or whole LIST 100 program LIST Space bar stops listing LIST 50 80 Lists specified lines or whole LLIST 100 program to printer LLIST Returns natural logarithm A LN X 2 Returns base ten logarithm B LOG Y 1 Switches to low resolution mode LORES 0 TEXT screen is set to background black When the standard character set is used When N 1 the alternate cha racter set is used Returns a substring starting at A MID character A of length L Z A L See Sound chapter Deletes current program and all NE
5. 2 4 4 BVC Branch on overflow clear Branch on V 0 BVC Oper Relative 2 50 zs i m MES JE aT Hb HE ud am aut 1 ap uy gf jT uf f jP a AL AL o x 19 b 1 1 IN 11 a M Name Operation Description BYS Branch on overflow set Branch on V 1 t 1 CLC Clear carry flag Clear decimal mode 1 CLI 0 1 i 1 CLV Clear overflow flag O V CMP Compare memory and accumulator CPX Compare memory and X M Index X CPY Compare memory and Y M Index Y DEC Decrement memory by one ere HN SN DEX Decrement Index 1 by one prts x ene z DEY Decrement Index Y Y 1 Y Appendix K E I Assembly Processor Language Addressing No OP Status Reg Form Mode Bytes Code Codes Hot BVS Oper Relative 2 70 1 4o 5 4 C CLC Implied 1 18 am A 4 D 0 Implied a D8 D ee a 1 i 1 86 CLI Implied 58 e m 4 V CLV Implied l 88 pas MUERE DI MI N ZC CMP HOper Immediate 2 C9 CMP Oper Zero Page 2 C5 CMP Oper X Zero Page X 2 DS Oper Absolute 3 CD Absolute X 3 DD OPer Y Absolute Y 3 D9 C
6. PLEASED TO MEET YOU followed by your name The semi colon prints your name after it Semi colons are not necessary in PRINT statements but may make the listing clearer They suppress the line feed so be careful about putting them at the end of lines Type RUN This sets the pro gram into operation from the lowest line number it also clears any variables previously set so you can keep running the program with different names Although it s not necessary with ORIC it s usual to put END as the last line of the program Type LIST and your program will scroll neatly up the screen Now add these lines 50 PRINT ENTER THE YEAR IN WHICH YOU WERE BORN 60 INPUT YEAR 70 LET AGE 1983 YEAR 110 PRINT YOU MUST BE ABOUT YEARS OLD N 120 GOTO 200 200 END If you make a mistake in a line you can delete the whole line by simply entering the line number Try typing 60 then LISTing the program Retype 60 INPUT YEAR Now RUN the program 23 ORIC Manual Je Je Je lt lt lt lt lt DECISIONS So far we ve used the computers to work through all the num bers without making any decisions Let s use ORIC s brain a little more Add these lines Feminists may wish to alter the wording of lines 80 150 80 PRINT EXCUSE MY ASKING BUT ARE YOU FEMALE N Y N 90 INPUT A 100 IF A Y THEN 150 150 PRINT WELL N AN ATTRACTIVE GIRL LIKE YOU MUST BE ABOUT 18
7. Line 100 contains a conditional branch A should be either Y ORIC tests to see if AS Y If this assertion is true THEN the program jumps to line 150 If this assertion is false i e if anything else has been entered then the program con tinues to the next line prints the age and then stops See the end of this chapter for a discussion on the use of ELSE You will probably see that the program only tests for asa reply OK or YEAH or JUST ABOUT would be counted as not Y and therefore false so be warned although ORIC 15 very good at obeying instructions these must be specified carefully in the first place You might like to try to alter line 100 to cope with other answers You can start with 166 IF A Y OR A YES OR A YUP THEN 150 Up till now all you ve been printing has been in capitals You ve probably discovered that SHIFT doesn t seem to work If you press CTRL and T at the same time you ll find ORIC S keyboard acts like a typewriter lower case small letters nor mally and upper case capitals when you hold SHIFT down at the same time If you press control T CTRL and T ORIC will go 24 J J JP jp J DP UD D au A 11 jT 11 11 jT J jT hi YY d 4 di 4 d d d Al i 4 4i 4 4d di i di di 4 di di d d 4 1 Chapter 3 Programming BASIC back to using capitals only To let y
8. 4 ddl j4 d d di b d d d d i b 4 dj 4 1 14 1 4 E 4i Chapter 4 Colour and Graphics A S C LI usually pronounced Askey stands for American Standard Code for Information Interchange It is fairly stand ardized and assigns code numbers to letters figures and symbols see appendix There is a BASIC command ASC that returns the value of a character in a string and this will save time as you will see in the next program 5 REM SIDEPRINT 10 HIRES 20 CURSET 50 50 3 30 N HELLO ORIC 40 FOR A 1TOLEN N 50 CHAR ASC MID N A D 0 l 60 CURMOV 10 10 0 70 NEXT A Lines 40 to 70 contain a loop that scans the length of N and prints the characters according to the CURMOV command Change N to your name or try changing the CURMOV parameters so you can see what happens Be careful you don t go off the screen or you will get an error message CIRCLES To draw circles simply type in CIRCLE followed by two num bers first the radius then the FB code The centre will be at the current cursor position Be careful your radius does not take the circumference off the screen Try this as a direct command in HIRES mode CURSET 120 100 3 then CIRCLE 50 1 If you have previously set PATTERN to a different value the circle will be drawn in dots etc Try this program for an interesting effect 41 ORIC Manual 100 LACE CIRCLES 110 HIRES 120 CURSET 120 100 3 130
9. one zero in base eight To show that it is not a normal or decimal or denary or base 10 number then it is usual to write it 10 Just as the column headings in base 10 numbers are in tens e g thousands hundreds tens units 10x10x10 10x10 10 so in base eight the headings are in eights e g 512 64 5 units 8x8x8 8x8 8 so 1241 is the same as 1x512 2x64 4x8 1 673 in base 10 61 0 RIC Manual In the language of the computer binary or base 2 the same rules apply but now there are only 2 digits 0 1 and the groupings are in twos e g 16 8 4 2 units 2x2x2x2 2x2x2 2x2 2 So in binary the number 10111 is the same as 1 x 16 0x 8 1x 4 1x 2 1 23 in base 10 This can get rather cumbersome when large numbers are involved In face you need 8 digits to make 255 and 65535 is 1111111111111111 sixteendigits It would be possible to ignore binary code for large numbers and stick to base 10 but that would give no clue as to how the number was stored on a computer A compromise is reached by using base sixteen or hexadecimal or hex as it is more usually called Base 16 needs 16 digits so letters are used above 9 This means that counting in hexadecimal results in this 0 1 2 3 4 5 6 7 8 9 A B C D E F You can see that fifteen in hex is F and so sixteen is 10 This gives column headings as follows 4096 256 16 units 16x 16x 16 16x 16 16 So 1
10. 105 ORIC Manual Loading XX If you have forgotten the program name or simply wish to load in the next program on the cassette then type CLOAD You can buy special computer data cassettes that are not very long CIO or CI5 or you can use good quality audio cassettes Short cassettes are preferable as it is easier to locate a program A final warning don t try and record on the plastic leader at the start of the tape Your ears may not mind missing half a note at the start of some music but ORIC will complain if even one byte is miss ing As well as saving programs normally ORIC allows you to be far more versatile in the use of your recorder If you CSAVE programs as above they are recorded at the fast rate of 2400 baud a measure of data transfer You should find that this speed is perfectly reliable provided the record replay head on the cassette recorder is clean and well aligned and you are using good quality tapes If there is a fault in the tape you may get the error message FILE ERROR LOAD ABORTED If you wish to be absolutely sure that your masterpiece is CSAVEd for posterity then you may add the letter S to the CSAVE instruction as follows which will transfer data at the super reliable speed of 300 baud CSAVE PROG 17 5 When you CLOAD slow programs you must type CLOAD PROG 1 S or ORIC will expect a fast load If you wish your program to RUN automatically once it has been loaded add
11. 30 PRINT THANKS If you draw a line or move a character it is important not to go off the edge of the screen or to print it in one of the protected columns You may realise this but another user may not If A is the horizontal position and B the vertical position on the HIRES screen then something like this may help If A 238 THEN A 238 IFA lt 1 THENA 1 IF B 198 THEN B 198 IFB 1THENB l 118 aT DT iT dT 4T 4T AT PIP T 4T 40 D 43 4T 41 47 41 41 41 aT Wi Ws M Wi We We WW MO M MM WD Wd M 3 M4 E 4d Chapter 72 Better Basic This should be useful provided the character is no larger than two pixels Change the values according to your requ irements You have to imagine the worst thing anyone could do to your program and even then it s more likely that someone somewhere will be able to crash it There is no such thing as a perfect pro gram but it is possible to mug trap or idiot proof your program to a fair degree You will then have what is more politely termed a robust program 119 222 A D hy CHAPTER 13 Machine code programs gt 2 71 77 V d z ZE 2 252 722 4 47 72 77 gt 74 PR EID SE i Pea A EEEE 27 m 2 277 ZZ bs Lh Sp lt P poo iub ed 1 l 1 1 ili idi J HI Yd n mm
12. 36 LET JOCELYN 28 Now type PRINT JOHN PRINT JOCELYN You should get 28 each time because ORIC has only remembered a variable JO which although originally set to 36 was reset to 28 Enter PRINT 4 JO and you can see how variables can be treated just like ordinary numbers So far we have only dealt with numbers How can ORIC remember names Just as there are numbers and also number varia bles there are strings and string variables Type LET N BLAKE Now type PRINT N 21 ORIC Manual You should see that BLAKE has been remembered as a string variable Try to set FP to your favourite person s name If you type PRINT N FP you should get both names on the screen The comma sets a space between the strings like using TAB on a typewriter ORIC has TAB settings five characters apart If you use a semi colon there is no gap between variables e g PRINT N FP It is possible to add strings together to make a new string Type LET AS NS FP then PRINT A This is called concatenation Try using CLEAR again to check if it clears string variables too Note You don t have to use LET to assign values to variables i e 10 is the same as LET A 10 to ORIC When we were talking about number variables you probably discovered that decimal fractions could be held in variables as well as whole numbers Try LET X 1 3 PRINT X You should get 0 333333333 ORIC can hold numbers bet
13. Mi Mi i li 14001 di Chapter 5 Editing Basic programs Remember moving the cursor anywhere on the screen does not alter the program lines Program lines are entered by copying exis ting screen characters using control A or by entering new ones from the keyboard Control X will allow you to escape from the line the cursor keys can jump over letters DEL will delete mistakes and RETURN will enter the new line Until you are confident in using these features always clear the screen and LIST the new line to ensure it has been entered as you wish You will discover that you can edit and copy lines extremely quickly and you will soon become proficient at using the various editing facilities on ORIC gt K gt gt F gt gt gt K gt K gt K gt TRON and TROFF If you are developing a Basic program and in spite of all your attempts it does not work as expected gives consistently strange results or simply stops execution with an error message then it 15 useful to know if the flow of control within the program is actually as you intended it Oric has two commands that allow you to do this TRON turns on a trace facility that prints up the line number being executed The line number itself is surrounded by brackets so that it is not mistaken for the actual screen display TRON cannot be entered as a direct command but has to be inserted in a program complete with line number e g 50 TRON Here isan example
14. memory with accumulator PHA Push accumulator on stack PHP Push processor status On stack PLA Pull accumulator from stack PLP Pull processor status from stack ROL Rotate one bit left memory or accumulator ROR Rotate one bit right memory or accumulator Operation No operation 4 Appendix sis 42 Assembly HEX Processor Language Addressing No OP Status Reg Form Mode Bytes Code Codes v sz He eee Hes F I ILE i NC LSRA Accumulator 1 4 N gt LSR Oper Zero Page 2 46 LSR Oper X Zero Page X 2 56 LSR Oper Absolute 3 4E LSR Oper X Absolute X 3 SE un S 1 1 Implied 1 5 MU okie d vo se NZ ORA Oper Immediate 2 09 ORA Oper Zero Page 2 05 ORA Zero Page X 2 15 Absolute 3 00 i ORA Absolute X 3 ID ORA Oper Y Absolute Y 3 19 ORA Oper X Indirect X 2 01 ORA Oper Y Indirect Y 2 11 pe eb PHA Implied 1 48 T cores 1 i PHP Implied 1 08 i NZ PLA Implied 1 68 i eges o es 4 4 D c Restored PLP Implied 1 28 qd t x Fev L Wed Sor 2 NZC Accumulator 1 2 ROL Oper Zero Page 2 26 ROL Oper X Zero Page X 2 36 ROL
15. 190 EXPLODE 200 WAIT RND 1 200 100 210 NEXT M 1000 REM CHARACTER DEFINITION 1010 FORN OTO7 1020 READ X POKE 46080 64 8 N X 1030 NEXT N 1040 DATA 18 12 30 45 45 30 18 0 1050 RETURN You will see from this program that you can have all the fore ground colours on the screen at the same time as well as changing background colours You do not have to POKE into the screen display PLOT will work as well Nomally the protected columns on the left of the screen control the INK and PAPER colours for the whole screen If you POKE an attribute on to the screen it occupies one character square and effects all the character squares to its right unless you POKE another colour attribute after it As the INK attribute is separate to the PAPER attribute it is not necessary to cancel it unless other cha racters appear to its right These would then take on the colour of the closest attribute to their left In HIRES mode it is possible to have a colour resolution of 200 lines by 40 character columns Again you have to POKE the position just to the left of the position you wish to alter This program POKES background attributes into the centre of the screen and foreground attributes to the far left The circles that are drawn take on the colour of the attributes according to their position on the screen 92 T dT dT IT iT dT p UT UT p IT p UIT p m IP j uam 4 Mi 4 LL dod 4 1
16. CTRL or RETURN or any other control keys you will get a low beep Try pressing CTRL and at the same time press F This will turn off the sound from the keys If you type CTRL F a second time the sound will return Now for some excitement Type ZAP then RETURN This will produce a rapidly falling whistling tone that suggests a galactic Laser gun Now try PING a bell like tone that can also be produced by typing CTRL and G SHOOT simulates the sound of a gun being fired EXPLODE generates an explosion Sel PING amp 6 4 These the four predefined sounds that should be useful in arcade action games They can be put in programs just like any BASIC commands 10 FORNN ITOIO 20 ZAP 30 WAIT 5 40 NEXTN This should fire off a salvo of ZAP s NOTE You must include a pause as in line 30 to allow the sound to finish before a new one is triggered The wait length depends on the sound 97 0 RIC Manual The main sound commands are SOUND MUSIC and PLAY In most programs it will be necessary to define the type of sound by the first two commands and to control the envelope by the third The envelope determines the shape of the sound i e whether it starts sharply like a guitar or smoothly like an organ These commands will take some time to become familiar with as they offer the chance to make ORIC sound like many existing instruments as well as any you care to invent White noise c
17. cd dg sd d o i Hl bi 13 Machine code programs It has been mentioned previously that computers do not yet understand normal English commands as these are ambiguous as well as idiosyncratic The best they can do is interpret a language like Basic that approaches to some degree a limited sub set of English Computer languages can be seen as a hierarchy with those that are close to natural language at the top high level languges and the binary code of machine language low level at the bottom The high level language that is supplied with ORIC is Basic The chip that translates Basic into machine code is called the Basic ROM ROM stands for Read Only memory and the interpreter program it contains is fixed during manufacture and cannot be altered If you have a 48K model it actually contains 64K of RAM Random Access Memory that can be changed and usually holds your programs If you purchase disc drives for large fast memory storage the internal ROM is masked out leaving nearly 64K of internal memory In this way other high level language such as Forth Pascal Logo Prolog and Lisp could be used with ORIC With all this potential for high level languages that are much clearer to understand you may wonder why anyone should bother with machine code After all it 1s estimated that it takes at least ten times as long to write as the equivalent program in a high level lan guage You do not get helpful error messages
18. from Numa Pomilius and Julius Caesar down to Pope Gregory have attempted to correct the calendar but it is still not perfect All this makes it rather more complicated to calculate which day of the week a particular date fell on The German mathematician Gauss worked out a formula that works for any date from 1752 when the Gregorian calendar was initiated in the U K and the Amer ican colonies 5 10 REM DAY CALCULATOR CLS 20 PRINT ENTER DATE MONTH amp YEAR 30 INPUT DATE D 40 IF D lt 1 OR D gt 31 THEN 30 50 INPUT MONTH M 60 IF M lt 1 OR M gt 12 THEN 50 70 INPUT YEAR Y 80 IF Y lt 1752 OR Y gt 8000 THEN 70 90 M M 2 IFM lt l THEN 12 1 100 110 120 130 140 150 Y STR Y C INT Y 100 Y VAL RIGHT Y 2 INT 2 6 M 0 19 D Y INT Y 4 INT C 4 C 2 DAY INT A 7 INT A 7 7 0 1 DAY DAY 1 160 FOR N 1 TO DAY 170 READ DAYS 180 NEXT N 190 PRINT DAYS 200 DATA SUNDAY MONDAY TUESDAY WEDNESDAY THURSDAY FRIDAY SATURDAY 67 CHAPTER 7 More mathematical functions 5 SA AK A ng NSS AC OPI DESOUE GEL re UL pes drug 4 d 4 4 4 d d 4 14 f U Uu uU uU U U U t wu 7 More mathematical functions TRIGONOMETRY ORIC has many functions that you will recognize if you have a sci entific cal
19. k 4 k 4 did 4 i 1 i 4 Wu d di d d 4 4i di 4l Chapter 9 Advanced graphics yours attribute code on loff pattern bits If an attribute is set then it continues until the end of the line unless it is reset To see how serial attributes can be used to control the display in TEXT mode try this program 10 FORA 0TO255 20 FORN ITO24 30 PRINT A SOME TEXT TO FILL THE SCREEN 40 NEXTN 50 FOR J 48042 TO 49002 STEP 40 60 POKE J A 70 NEXT J A Lines 20 to 40 fill the screen with text Lines 50 60 POKE variable A onto the screen You should be able to see which values of A control colour flashing etc and which result in normal or inverse text being printed When A is between 24 and 3 1 the screen will look very strange This is because you are changing the synchronisation temporarily See Appendix C for details This program demonstrates how serial attributes can control the colour of a predefined characters on the TEXT screen 5 REM DROPPING ALIENS 10 GOSUB 1000 CLS 20 FORM ITO20 30 PAPER INT RND D 4 4 40 A RND 132 1 50 ZAP 60 FORN 0 TO 1100 STEP 40 70 POKE 48039 N A 1 80 POKE 48040 N A 64 90 48039 3 6 2 100 48040 N 6 64 9 ORIC Manual 110 POKE48039 N A t3 3 120 POKE 48040 N 3 64 130 SOUND 1 N 2 0 140 PLAY 1 0 5 5 150 POKE 48040 N A 32 160 POKE 48040 N A 6 32 170 POKE 48040 N 3 32 180 NEXT N
20. 00101010 00101011 00101100 00101101 00101110 00101111 00110000 00110001 00110010 00110011 00110100 00110101 00110110 00110111 00111000 00111001 00111010 00111011 ORIC Manual BINARY 150 00111100 00111101 00111110 00111111 01000000 01000001 01000010 01000011 01000100 01000101 01000110 01000111 01001000 01001001 01001010 01001011 01001100 01001101 01001110 01001111 01010000 01010001 01010010 01010011 01010100 01010101 01010110 01010111 01011000 01011001 01011010 01011011 01011100 01011101 01011110 01011111 01100000 01100001 01100010 01100011 01100100 01100101 01100110 01100111 01101000 01101001 01101010 01101011 01101100 01101101 01101110 01101111 01110000 01110001 01110010 01110011 01110100 01110101 01110110 01110111 01111000 01111001 01111010 01111011 01111100 01111101 01111110 01111111 JT T Y YT GT Y T P T Y UT IT IT HIT Y IT UIT UT IT P IP um If ZIV E 66 8c LT 8 VIV 9c C SIV vC 9V La 77 z SW NO z 6l tV 02 61 sa GND 81 LI LG ra 81 11 Cv IOBIUOD Aey L GND 9I 1 9I SI IV 192100 ARTAY 9 QNO ti el rl gI punog GND ZI II ra 21 H V 46 Punos p DNAS i 6 gl 6 uj ede c ania GND 8 L OUI 8 L M A GND 9 Id O I 9 O I ede GND pb oq I3S
21. 1 1 d d d Ji M DD 300 uu o di b 3 1 5 10 20 30 40 50 60 70 80 90 Chapter 9 Advanced graphics REM SPLIT CIRCLE HIRES FOR N 41060 TO 48979 STEP 40 POKE N INT RND 1 7 1 POKE N 45 INT RND 1 7 16 NEXT N CURSET 120 100 3 FOR X 95 TO 1 STEP 1 CIRCLE X 1 NEXT X The second program shows how a graph can have a multicoloured start and then be just one colour for a pre defined section You can of course POKE flashing or double height attributes on to the screen using this method 5 10 20 30 40 50 60 70 80 REM COLOUR SINE HIRES FOR 40960 TO 49079 STEP 40 POKE N INT RND 1 7 1 POKE N 100 1 NEXT N FOR A PI TO PI STEP 0 02 CURSET A 38 120 SIN A 99 99 1 NEXT A 93 Jo l J iu 1 1 A d r in Z POL 2 24 A zv V 327 Lud D Le 4 22 2 gt So pP I CHAPTER 10 Sound Pirate P pes Z EF BEE pr 39 Ure T Z 02257 PIAF Lp pod Z y 2 Lia 4 2 tre Z 22 a Z me 4 i ib 2 4 A l i idi Jj n us i i42 Ws UM ab di Mi d 1 10 Sound ORIC contains some very sophisticated sound commands using specialist chip that can synthesize 3 different tones as well as a noise channel You have already experienced some of the sounds available each time you press a key ORIC makes a high beep If you press
22. A N with the squares of the loop number N Lines 40 to 60 print the contents of the array on the screen Note that it is not necessary to fill every element in an array Any empty elements will contain zero of An array like those we have just considered is similar to a column numbers but it is also possible to have rows and columns in other words a two dimensional array Multi dimensional arrays must be dimensioned before use 10 DIM A 5 5 20 FORN 1 05 30 5 40 A N M N M 50 NEXT M N This will load numbers into 25 locations You can probably see from the program that they happen to be the answers to some simple multiplication sums 58 WH n m qm m dm aum aaa 17 D l li Chapter 6 Number crunching Contents of array A N M after execution of program The numbers in the brackets identify which element you wish to refer to and are known as subscripts A 2 3 is 6 and A 5 5 s 23 If you wish to have even more dimensions than it is perfectly possi ble It is important to remember however that even DIM N 18 10 19 has 1000 elements and you may run out of memory rather quickly k k k k k k k k LOGS I have mentioned that numbers can be written using scientific notation e g 1 6E 2 is the same as 160 More usually 1 6E 2 wouldbewritten 1 6x10 which means 1 6 1OxlO or 1 6x100 The small 2 in 102 means write the
23. GCL REM LDY GHC REM STA CURBAS REM STY CURBAS 1 LDA y REM JSR SYNCHR REM JMP PRINT 170 DATA 84 13 180 DATA A9 3B 190 DATA 20 DB CF 200 DATA 4C 61 CB 210 DATA FF 220 DOKE 2FS 400 If you type IX Y ORIC then ORIC will be printed at co ordinates X and Y on the screen To define amp to mean RETURN VERTICAL CURSOR POSITION 128 5 REM EXTENSION CMD VERT CURS POS 10 FOR N OTO5 20 READ DTA 30 POKE 400 N DTA 40 NEXT 50 DOKE 2FC 400 60 DATA AC 68 02 70 DATA 4C FD D3 M a dT HT T IT LLL dT IT 4T op um iL ib ib ds Chapter 13 Machine code programs It is useful to know which line the cursor is on if you need to use the double height feature so you do not end up with tops of letters under their bottom halves A suitable line in a program to protect against this would be 500 IF amp 0 2 lt gt INT amp 0 2 THEN PRINT This will move the cursor down to an even line Some of page 4 locations 0400 to 0420 has been reserved for your own machine code routines Anywhere in memory may be used for longer programs but a Basic program may over write it if it occupies the USER PROGRAMS space in RAM To reserve memory for machine code programs the top of the user area can be lowered To find its present position enter PRINT DEEK A6 Work out how many bytes you require for your progr
24. Oper Absolute 3 2E i ROL Oper X Absolute X 3 3E NZC ROR A Accumulator 1 ROR Oper Zero Page 2 66 ROR Oper Zero Page X 2 76 Absolute 3 6E ROR Oper X Absolute X 3 7E 163 ORIC Manual Name Description TXA Transfer index X to accumulator t TXS Transfer index X to stack pointer Transfer index to accumulator 164 X A Operation if Assembly Language Addressing Form a Sti LE T TXA Implied TXS Implied Seah E Sess TYA Implied aoe Se es y HEX Processor Code Codes EM EM A QA NZ OP Status Reg J AT Y GT Y T QT Y Y Y Y Y Y YP Y PIP P o nD p T
25. T V Most T V s purchased in the last 15 years will operate satisfactorily although a black and white T V will only give you shades of grey Now the moment you ve been waiting for switch on the mains and tune your T V to approximately Channel 36 If you have a rotary tuner this won t be difficult otherwise tune in a spare button When you are in the right place you should see the following picture on your T V ORIC Manual ORIC EXTENDED BASIC V1 6 1983 TANGERINE x BYTES FREE READY If you look at the back of ORIC you will see some other sockets The setting up diagram shows you their particular function Some of them will be useful fairly soon some will be used as you expand your system The most important socket is for the cassette recorder Almost any make will do cheap portables are better than expensive hi fi models When you type in a program and want to save it ORIC will turn it into a sound signal that can be recorded This can be reloaded whenever you wish and you won t need to type it again You need a lead with a three or seven pin DIN plug on one end and either a DIN plug or 3 Smm jack plugs on the other according to the sockets on your recorder Next to the cassette socket is the R G B colour monitor socket The signal that comes out of ORIC through the T V socket has to be coded into a U H F signal for your television set which then decodes it A monitor is like a T V set without the sound
26. and tuning section If you use ORIC with a monitor you ll get an even better picture The signal does not have to be encoded and decoded If you want to make a permanent record of what ORIC prints on the screen you can connect a printer via the next socket To make it easier most manufacturers make printers that use standard plugs ORIC will connect to any printer that has a Centronics interface The last socket is the largest and provides ways of connecting up ORIC to many other pieces of equipment Some examples are extra memory games cartridges joysticks and of course the modem This device will allow ORIC to download PRESTEL pages or even programs and to send and receive electronic mail via the PRESTEL MAILBOX system Underneath ORIC is a little button that you may need a pencil to 12 W P qm qnom qp P qp qp gm qp p m m om m qm m qp UP IP JP pgp 1 d d d di d Al 41 14 7 4 Ai 41 4 4 q S w a gi Chapter 2 Setting the Computer Up operate This is a RESET button and is an emergency device to get you out of never ending loops It does not switch off the power but only stops execution of a program It could also be referred to as a warm start button as it does not destroy the contents of the memory 13 4 di dd di 4 4 4 4 41 1 Id tdi di ldi 4 4 04 void EU CHAPTER 3 Programming in Basic 4 Wi b d M M 14 ld 7 E 14
27. by pressing the DEL key Press DEL twice and the cursor will backspace move to the left two positions To delete a complete line as you are entering it hold down CTRL and X A backslash will appear at the end of the line and the cursor will jump down to the start of a new line If you LIST a long program you probably find that it flashes up the screen too fast to read To halt the listing press the space bar once Pressing any key will continue the listing To halt the listing completely hold down CTRL and C Control C will also stop the execution of most Basic programs They can be restarted by typing CONT for continue unless you have changed any of the program or its variables Then you will have to use RUN or GOTO gt K OK gt gt gt gt gt F gt F ok 49 ORIC Manual COPYING It would be very time consuming to have to re type whole lines par ticularly if they contain complicated information You are not all owed to have lines that are longer than 78 characters Very long pro gram lines are difficult to read and spoil the lay out of the listings ORIC will give out a PING if you try to exceed this number Should you need to change a line ORIC has a COPY facility To see it in action type this short program in 10 REM EDIT TEST 20 A 20 B 30 30 C A B 40 PRINT C If you decide that line 20 should read A 25 B 5 and that line 30 should read A B this is what you do LIST the program and it
28. can use the screen to type on directly and when it s full it will scroll up automatically The TEXT area is also used for low resol ution graphics Before you experiment with LORES it would be a good idea to discover which colours are available for use There are two colour commands INK and PAPER These set the foreground and background colours respectively and can be used either as direct commands or in programs They have to be followed by a number 0 to 7 to specify which colour and can be used in TEXT or HIRES modes 0 BLACK 1 RED 2 GREEN 3 YELLOW 4 BLUE 5 MAGENTA 6 CYAN 7 WHITE Try them out now If you re used to computers that have to clear the screen before they can change colour you will find that ORIC doesn t need to do this Here is a short program to show you all of ORIC s colour combi nations 5 REM COLOURS 10 TEXT 20 FORN ITO25 30 PRINT THIS TEXT IS IN THE FOREGROUND COLOUR 40 NEXT N 50 FORI OTO7 60 FORP OTO7 70 INK I PAPER P 23 ORJC Manual 80 WAIT 100 90 NEXTP 100 NEXT I 210 INK7 PAPER 4 Of course when the foreground and background colours are the same you won t be able to read the words AM I FOREGROUNO P OR BACKGROUND For low resolution graphics you can use the screen in TEXT mode or you can enter LORES 0 or LORES 1 The screen area available for plotting is from 0 to 38 in the X axis horizontal and from 0 to 26 in the Y axis vertical P
29. character cells by B rows FILL B A N with N value There are 200 rows and 40 cha racter cells N must be an integer between 0 and 127 138 JPTT TI Y P P P T Y 4T uv IT uv UT T Tum p p A dob uH d 1 M M M h Ch MM d EN FOR TO STEP NEXT FRE GET GOSUB GOTO GRAB HEX HIMEM HIRES IF THEN o ELSE Chapter 15 ORIC Basic Produces the result of a PRINT FNA X predefined function Creates a loop to repeat all FORN ITO program lines between FOR and NEXT N NEXT STEP determines the incremental size If omitted 1 is used Returns the amount of memory FRE 0 available in bytes Also Forces variable garbage 9 collection Strobes the keyboard and waits GET A until a key is pressed Causes program branch to line GOSUB 1000 number specified See RETURN Unconditional branch to line GOTO 4000 number specified Assigns the area in memory from GRAB 9800 to B400 48K or from 1800 to 3400 16K to user RAM See memory map Prints the value V as a hexa PRINT decimal number Lowers top of memory available HIMEM 8700 for BASIC programs Memory above may then be used for machine code programs Switches to high resolution mode HIRES Background is set to black fore ground to white cursor to 0 0 Text lines remain in existing colours If the expression following IF is gt IOTHEN true then executes all instructions PRINT
30. counts to itself until the final number is reached This is how it works 25 ORIC Manual 10 FOR X TO 1000 STEP 20 PRINTX 30 NEXTX 40 PRINT PHEW THAT S FINISHED Line 10 sets the counter X to 1 then goes to line 20 There it prints X which is 1 and then goes to 30 This says NEXT X so it shoots back to the start of the loop at line 10 and increases it by the STEP number i e X is now 2 It prints X in line 20 then repeats as before until X is 1000 This time it tries to make X 1001 but it has been told to only go up as far as 1000 so it jumps to the next line 40 where it prints FINISHED If you change the STEP number to 2 then it will print 1 3 5 7 etc You can leave it out and ORIC will assume you want a STEP size of Try other STEP sizes yourself FOR NEXT loops can count backwards but you have to specify the STEP number as a negative quantity 10 FOR X 1000 TO 1 STEP 1 will count downwards If you make a mistake in the numbers e g FORX ATO2STEP5 Or FOR X 5 TO 188 STEP 1 26 d ad dr au a d am jm jm au dm aur aum gm dur h mar d PI o 4 14 d d 4 lh 4 14 u d 4 d di 4 di di Chapter 3 Programming in BASIC then the action in the loop will still be performed at least once because the test for whether the loop is completed is not made until the loop has reached the NEXT statement and returned to the start Ano
31. exact answer 5 REM ITERATIVE ROOTS 10 INPUT THINK OF NUMBER S 20 INPUT GUESS THE 30 PRINTG 40 X S G 50 G X G 2 60 R G G 70 IF R lt 5 0 000001 AND R gt S 0 000001 THEN GOTO 90 80 GOTO 30 90 PRINT ROOT G iThere isanother use for ORIC s high speed maths brain The 17th Century mathematics Leibnitz who made calcul us possible 64 IT ATL LITE Gb TD Kp a a I fal P IT IT dob s dd dle lie de d CUu Wi tdi dd d d d d 1 Chapter 6 Number crunching discovered a way of calculating m is an irrational number in other words it can never be calculated to a finite number of decimal places Leibnitz discovered that this sequence approached closer and closer to the true value 4 1 etc You should be able to see a regular pattern in the fractions ORIC loves patterns as they can be put in loops If you were to try to calculate the above formula with pencil and paper it would take you a long time even uP to 1 9 all the worse wh en you realize that the answer isn t close enough until you ve looped several hundred times Poor Leibnitz but lucky you Try this program 5 REM SLOW PI 10 CLS 20 DEF FNA N VN V N 2 30 FOR X 3 TO 10003 STEP 4 40 S S FNA X 50 APPROX 4 14S 60 PRINT APPROX 70 NEXTX Line 20 defines a function A containing a variable N
32. faults are much more difficult to trace and machine code 1s difficult to document and dif ficult to understand so why attempt to learn it An understanding of machine code will help you undertand the workings of computers and efficient machine code programs are executed at a much faster rate than any high level language If you imagine speaking to a German who in turn translates your instruc tions to an Italian before a job is carried out and you will see the advantage of being able to speak to the Italian in his own language There are several ways in which machine languages can be made more comprehensible Firstly it is usually written in hexadecimal a page of binary soon blurs into a mass of zeros and ones and deci mal numbers do not readily show you what is happening at byte level 123 ORIC Manual This is why the facility is provided on ORIC to enter numbers in either decimal or hexadecimal form rather than wasting time doing base conversions It also provides a code that is easier to read In the heart of ORIC is the most important chip the central processor unit All computers need a C P U but they do not all use the same model Any other computer that uses the same C P U can within the limits of the computer use the same machine code program ORIC uses a 6502 processor from Rockwell Inter national Corporation Other processors you may come across are 6800 6809 780 and 8080 These all operate in slightly di
33. i Chapter 72 Better Basic make their structure clear They will of course work with the semi colons and indenting removed As has been previously mentioned it is usual to space program lines 10 apart to allow for additions at a later date To complete your program it needs a title as well as your name and the date upon which you completed that particular version This makes it clear to you and anyone else what you intend the program to do and it reminds you when you wrote it At a later date you may acquire a printer Listings produced by this means will look much neater and your programs therefore easier to decipher if they are neatly indented Deciding on a program and building it up in this manner is called top down programming Building one up from program lines is called naturally enough bottom up Top down programming produces a clearly defined structure It also means that you rarely use GOTO statements Although they appear initially to be the programmer s friend their unrestricted use all over your programs will make them difficult to understand and lead to that unpleasant syndrome spaghetti programming 10 PRINT ENTER THE DATA 20 INPUT A 30 IF A 30 THEN GOTO 50 40 GOTO 10 50 GOTO 70 60 PRINT WAS MORE THAN 100 STOP 70 PRINT A WAS THE LAST NUMBER 80 IF A gt 100 THEN GOTO 60 90 END This is rather an extreme example but it does demonstrate how confusing unstructured programs
34. in some computers However this is not quite how ORIC manages it In each byte only the last six bits contain character information Each character can therefore be thought of as occupying 8 rows of 6 dots Each row is a byte of which the last 6 bits determine its design If a bit is 1 then the cell is on and if O it is cells are in foreground colour off cells are in back ground To look at the contents of any memory position we use PEEK To change the contents we use POKE The characters in the set are stored in the order of their ASCII codes The ASCII code for A is 65 so the pattern for A should be stored at 46080 65 8 1 e 46600 and the next 7 bytes 46600 46601 46602 46605 46604 4 6605 46606 466011 The zeros and ones form a letter A It is very easy to change it Try this POKE 46600 31 POKE 46601 21 POKE 46602 31 POKE 46603 4 POKE 46604 31 POKE 46605 4 POKE 46606 10 POKE 46607 17 88 MD IK P T IT IT UT p IT IT UIT IT p p p QT p p up p um qq jp Uu 3j b N 12111114137 Chapter 9 Advanced graphics Type A now you have been invaded by ORIC Any A will now appear in its new guise as you have redefined how ORIC draws an A It would take a long time to POKE numbers one at a time so it is better to write a short program to redefine characters Here is a frightening program that redefines the entire character set When y
35. j de i L 14 J d L L L dowd bb i 1 3 d d d 1 ORIC 1 Basic Programming Manual by J ohn Scriven Edited and produced for Oric Products International Ltd by Sunshine Publications Ltd London Sunshine Publications Ltd 1983 d Jj d a db di T D d bd d B b d dob d d Contents CHAPTER 1 Introduction CHAPTER 2 Setting the computer up A guide to putting your Oric to work CHAPTER 3 Programming in Basic Learning Oric s language CHAPTER 4 Colour and Graphics The Oric can work in four Modes and eight colours CHAPTER 5 Editing Basic programs There are powerful Editing commands to help you write your own programs CHAPTER 6 Number crunching Your Oric is also a powerful mathematical tool CHAPTER 7 More mathematical functions A guide to trigonometry and algebra CHAPTER 8 Words Handling words in strings CHAPTER 9 Advanced Graphics High resolution plotting and defining your own characters Page Page Page Page Page Page Page Page Page 31 47 53 69 77 85 ORIC Manual CHAPTER 10 Sound The Oric has four separate sound channels and four predefined sounds for games CHAPTER 11 Saving programs on tape A guide to the cassette operating system CHAPTER 12 Better Basic With a bit of practice and care you can improve your Basic programs CHAPTER 13 Machine code programs Introducing
36. lI UNTIL F gt 2 PI F 0 CURSET 200 140 3 CIRCLE30 1 WHEEL REPEAT DRAW29 SIN F 29 COS F l CURSET200 140 3 F F 1 UNTILF 2 PI CURSET100 15 3 REPEAT READ A B DRAW UNTIL B 25 CURSET 160 20 3 FORN 1 TO 10 TEXT 1 READ L CHAR 1 01 CURMOV 7 0 3 NEXT CURSET 160 32 3 FOR N 9 2 READ L CHAR 0 1 CURMOV 7 0 3 NEXT DATA 10 0 10 10 0 20 0 20 40 0 10 10 15 0 5 10 60 60 0 25 DATA 79 82 73 67 32 82 73 68 69 83 DATA 84 79 32 87 79 82 75 33 33 45 CHAPTER 5 Editing Basic programs r T fi T T T d i 1 d J 1 MWh did d db bs cc d d di i Sob lj j i di 5 Editing Basic programs When you write a program and wish to change a line there are several methods of altering or deleting existing instructions If the whole line is incorrect then typing the line number followed by RETURN will delete the entire line 10 PRINT HELLO 20 PRINT OOPS 30 PRINT GOODBYE Type 20 RETURN Now type LIST You will see the program listing as before but this time with line 20 missing 10 PRINT HELLO 30 PRINT GOODBYE If you wish to delete all the lines in a program then type NEW If you are typing a line in and discover that you have made a mistake you can rub out the last character entered
37. large number down this number of times and multiply them together e g 10x10 So 10 means 10 x 10 x 10 x 10 or 10000 The small number is called the index or exponent 10 is usually read as 10 raised to the power of 4 or just 10 to the power of 4 This gives us an introduction to logarithms or logs for short because the log of a number is the power to which 10 must be raised to produce that number i e 4 is the log of 10 000 To find the log of a number between 1 and 10 we have to find the index that will produce that number It must be between 0 1 If you type PRINT LOG 5 then the log will be returned You should get 0 698970004 To check if this really is the log of 5 try raising 10 to that power and see if 5 is produced Type PRINT 10 0 698970004 and see if you were right The sign means to the power of and is SHIFT 6 on the keyboard Remember 10 log x 59 ORIC Manual As well as base 10 or common logs there are also natural logs available on Oric Type PRINT LN 5 You should get 1 60943791 which is the natural log of 5 How can there be more than one log Base 10 logs are the power to which 10 must be raised to produce that number Natural logs are the power to which e must be raised to pro duce that number e is 2 718281828 is the result of this series 1 1 7 m 2X3X4 errors The natural exponential of a number is the inverse of the natural log and ca
38. pictures etc You will probably find a printer most useful in producing listing s so you can see the structure of a complete program They are also essential for getting hard copy of electronic mail 134 UT aT aT aT iT TT dT d aa er i ib M dich Hi A H8 d Lb b u C H b d bh li d di CHAPTER 15 QU uL b ib ib Zr e HH di bh di i olde di i 1 1 1 y 15 ORIC Basic COMMAND EFFECT EXAMPLE ABS Returns absolute value ABS 4 is 4 ABS 4 is 4 ASC Returns ASCII code of first cha A ASC N racter in string See appendix ATN Returns arctangent in radians Z ATN Y 4 CALL Transfers control to machine code CALL X routine starting at address X Return to Basic on reaching an RTS CHAR Draws a character at current CHAR X S FB cursor position top left of cha racter is at cursor position X is ASCII code 32 127 S is either 0 standard character set or 1 alternate character set FB is 0 to 3 see below CHR Returns the ASCII character that CHR value corresponds to the value 32 128 CIRCLE Draws a circle centred at current CIRCLE R FB cursor position No part of the circle may leave the screen R is the radius 1 119 FB is 0 to 3 see below CLEAR Sets variables to and strings to CLEAR null empty CLS Clears screen display CLS CLOAD Loads file name from
39. position of the cursor Again ORIC needs to know X Y and FB numbers Make sure that the value of X or Y plus the current cursor position does not take you off the screen or you will get an error message DRAW X Y FB will draw a straight line from the current cursor position to the current cursor plus X and Y Try this short program You should find it draws a square Notice that negative numbers draw from right to left or from down to up If the shape isn t quite square enough try changing lines 30 and 50 5 REM SQUARE 10 HIRES 20 CURSET 60 40 3 30 DRAW 120 0 1 40 DRAW 0 120 1 50 DRAW 120 0 1 60 DRAW 0 120 1 REMEMBER Changing modes or even typing HIRES again will rub out your picture permanently gt gt gt SKK gt F gt F gt gt PATTERNS ORIC has yet another trick for you When you switch on the DRAW command is set to draw a continuous line It s possible however to draw dotted lines dashed lines etc according to your own specification This is how it works If you remember it was mentioned earlier that ORIC thinks in 8 bit bytes so you can count from 0 to 255 is using 8 zeros and ones When ORIC is switched on the number 255 is loaded into the pattern mask 255 is written as 11111111 in binary code 39 0 RIC Manual You can set the mask to any number from 0 to 255 to get different effects If you want equal sized dashes you could type PATTERN 15 15 1500001111 in b
40. reading the manual but you will only become proficient by using ORIC frequently We hope that you will find it a friendly computer that will become the heart of an expanding system You will soon discover about ORIC s drivability Even beginners will find computing is easy with ORIC PLEASED TO MEET You CHAPTER 2 Setting the Computer up EE Z WSN SX WA WS BEES NS lt S mom op Ts TD MM Ti T T T T oat 4 dl dl 1 141 8 dl d di di 2 Setting the Computer Up Power Supply Unit TV MAINS LEAD CENTRONICS PRINTER INTERFACE EXPANSION PORT aeu K K BEEBE R V V Y Y Y YV RE Sea R om 8 M M M E M EM K M SE When you unpack your ORIC you will notice that it has a key board to enter information and several sockets at the back It needs these to communicate with the outside world First of all connect the power supply according to the instructions on the lead and push the small plug into the socket at the back ORIC only needs a low D C voltage so never plug it directly into the mains The keyboard provides an input but you will not see the results of any key presses unless you plug it into a T V Using the connecting lead plug one end in the back of ORIC and the other end to the U H F aerial socket on your
41. the other attributes will achieve This program demonstrates mixing graphic patterns with colour and flashing attributes Note that line 130 avoids using the control codes that disturb the screen synchronization 100 REM FILL DEMO 110 HIRES 120 REPEAT 130 A RND 1 128 1 IF gt 23 AND A lt 32 THEN 130 140 CURSET RND 1 90 10 RND 90 10 1 150 FILL RND 1 90 LLA 160 UNTIL KEY lt gt odi gt 2K gt gt cK KK DOUBLE HEIGHT AND FLASHING CHARACTERS If you want special characters e g flashing or in double height there is a routine in ORIC that will achieve this for you If you look at the appendix for ORIC attributes you will see a table specifying all the effects that are available You will also need to refer to the table that covers control characters Control D toggles auto double height on off This can only be accessed through a print statement Type PRINT CHR 4 43 0 RIC Manual Anything you enter now will appear twice in consecutive rows Try it out Help How do we stop it As it s a toggle action switch typing PRINT CHR 4 a second time will turn this action off The other control characters are achieved in a similar manner But back to the double flashers The following program will give you the effect you desire 10 PRINT CHR 2 20 PRINT CHR 4 CHR 27 N DOUBLE FLASH CHARACTERS 30 PRINT CHR 4 Don t be alarmed if it looks fearsome I ll explain
42. um mom um Tomum b LL oL U i H H iW H H i 1 di H al 1 CHAPTER 9 Advanced Graphics uU L2 bD UU L Lb D al 1 Ti 3 3 1 B U U U U 1 9 Advanced graphics USER DEFINED GRAPHICS When ORIC is switched on both the standard and alternate cha racter sets are loaded into Ram The standard character set contains all the usual ASCII characters as shown in the appendix and the alternate character set contains teletext graphics Either set can be completely or partly overwritten In a game you may wish to use text and also a few graphics cha racters you have defined yourself perhaps small aliens You can choose a standard character that is not used frequently e g or and redefine it In a word processing situation you may wish to have the character set containing not English characters but a Greek or Russian alphabet To understand how this can be achieved we need to know how the characters are stored originally Looking at the memory map shows us that the standard set is stored between locations 46080 and 47104 i e they take up IK 1024 bytes If there are 128 cha racters then each must use up 8 bytes 128 x 8 1024 This may lead you to think that they are stored in an 8 x 8 chess board tocat fo Binary Valle Deci mal equivalent 6609 8 46601 O 2 0 46662 O 34 46603 O 3 4 46604 O 62 6605 O 34 46606 O 3 4 46607 O 0 87 ORIC Manual arrangement as
43. will appear on the screen It is a good idea to press control L CTRL and L at the same time to clear the screen each time before you LIST the program You can now move the cursor up the screen using the arrow keys next to the space bar The cursor will move in the direction of the arrow on the key When the cursor is next to line 20 hold down the CTRL key and at the same time press A The cursor will move to the right and each character it passes over will be entered in the input buffer a temporary store When the cursor is over the 0 in 20 release CTRL and A and press 5 A 5 will appear instead of the 0 Continue to copy the line using control A until the cursor is positioned over the 3 in 30 Rel ease control A and enter 5 The 5 will appear in place of the 3 As you do not want the 0 in your new line simply press RETURN and the edited line will be stored in the program memory The screen display will show A 25 B 50 which may make you think it is incorrect Clear the screen as before and LIST the program Voila Line 20 now reads A 25 B 5 Because you did not copy the 0 at the end of the line it was not stored as part of the new line To change line 30 move the cursor up to the line and then copy as far as using control A Enter then copy B and press RETURN 50 Y Wm qv gm p p P p IP j 41 4b dd jp jP us j di 1 hi 1 uu ua 10
44. written 1 x 10 10 100 can be written 1 x 10 10 x 10 1000 can be written 1 x 109 10 x 10 x 10 and so on ORIC could write 1 x 10 as 1 00000000 3 In fact numbers up to 999999999 are usually shown as they are normally written as ORIC is accurate to 9 digits Try these PRINT 999999999 1 then PRINT 9999999999 1 This shows you how scientific notation works and also how the number is rounded off Enter large numbers and see how Oric prints them You can also enter numbers such as 2 3E 4 to see what their equivalent is An easy way to remember how to convert these numbers is to say 2 3E 4 means Write down 2 3 Move the figures 4 places to the left Fill any spaces with zeros 2 3 28 0 1 place or times 10 230 0 2 places or times 100 2300 0 3 places or times 1000 23000 0 lt 4 places or times 10000 55 ORIC Manual So 2 3E 4 1s the same as 23000 2 3E 4 What does this mean The negative sign after the E does not mean the number is negative simply very small It means Write down 2 3 Move the figures 4 places to the right Fill any spaces with zeros 2 3 0 23 1 place or divide by 10 0 023 2 places or divde by 100 0 0023 3 places or divide by 1000 0 00023 4 places or divide by 10000 So 2 3E 4 is a very small number 0 00023 If the number is a large negative number it would be written 2 3E 4 If the number is a very small negative number it would be writte
45. 14 14 Id PI 14 14 P 4 14 3 Programming BASIC d sa m m m um First the bad news ORIC doesn t understand English But now the good news you don t have to learn a complicated electronic lan guage because ORIC speaks a language called BASIC Beginners All purpose Symbolic Instruction Code This language was inven ted in 1964 to help people to write computer programs easily If your machine is switched on we ll see how easy this is Type PRINT HELLO and then press the RETURN key As you typed the letters in they should have appeared on the screen and when you pressed RETURN the word HELLO should have appeared just under it The flashing square is called the cursor It tells you where the words appear on the screen PRINT is a BASIC command yet it means the same as it does in English Try PRINTing 17 0 RIC Manual some other things on the screen Remember to put quotation marks round what you want to say and don t forget to press RETURN Now enter WRITE HELLO and press RETURN Oops You ve just been given an error message The words SYNTAX ERROR means you ve made a mistake Although BASIC is easy to learn and close to English you must use the correct words or ORIC won t understand A peek inside the ORIC may help to clarify things a little Inside ORIC there are several microchips The most i
46. 2300 VARIABLES 0200 PAGE 1 STACK PAGE 0 ALLOCATED BOTH MODES 0400 N B 1 For 16K systems all addresses except ROM are minus 8000 hex 2 All addresses are given in Hexadecimal 145 Appendix B Control Characters all available from the keyboard or through PRINT statements 1 Toggle action on off CTRL T Caps lock CTRL P Printer CTRL F Keyclick CTRL D Auto double height CTRL Q Cursor CTRL S V D U CTRL I Protected column far left 2 Screen format characters CTRL J Line feed CTRL L Clear return CTRL M Carriage return CTRL N Clear row To use in Print statements use PRINT CHR x where x is a number A 1 B 2 etc e g CTRL D CHR 4 146 LAT IT 4T iT 4T 4T 40 40 jT iP um um um am 4m amat apad ad at al ai Appendix C Attributes De Ds Da bs b b bo Mo Ms Ms 2 0 FGND BLACK BLACK 1 RED A RED 2 GREEN B GREEN R 3 YELLOW YELLOW 4 BLUE D BLUE T 5 MAGENTA MAGENTA 1 6 CYAN F CYAN V 7 WHITE G WHITE 8 SH ST STD H TEXT 60HZ X 50 Hz applicable in U K 9 SH ST ALT TEXT 60HZ A DH ST STD J TEXT 50HZ ss B DH ST ALT K TEXT 50HZ SH FL STD L GRA 60HZ D SH FL ALT M GRA 60HZ 1 DH FL STD N GRA 50HZ F DH FL ALT O GRA50HZ L escape character SH SINGLE HE
47. 2AF in hex is the same as 1 x 4096 2x 256 10x 16 15 4783 in base 10 Why choose such a horrifying number system Perhaps you ve guessed it shows at a glance how the numbers are stored in a computer by taking blocks of four bits at a time FO can be stored in one byte F 0 1111 0000 62 l ws YJ p p I Ip IP IP p P P p m T p p jT JT p p p pp im 1c Wu Uu wo Wd Ws 1 die Mb Eos usos uon Wd Ws du d M Chapter 6 Number crunching The enormous binary number that is the equivalent of 65535 in base 10 becomes FFFF in hex You may be able to see now why 65535 is the highest memory location you can address using two bytes Oric will recognize hexadecimal numbers as such provided they are preceded by a pronounced hash So PRINT produces 26 Try out some conversions for yourself The largest number you may convert is FFFF Check your results against the table in the appendices NOTE You may find some books that identi fy hex numbers by use ofa but Oric will interpret this as a string sign If you need to convert between hexadecimal and base 10 num bers you would use i e PRINT 10 will produce 16 To convert a decimal or base ten number into a string containing the value and preceded by a type PRINT 9 16 This will produce 10 As with there is an upper limit of 65535 i e This program will print out base 10 num bers up to 255 and also
48. 72175 DIIIL DALEKE Tm FO Td L 2 ome wae vardpup r d dr amar raram 2 4 4 42 u aoodasrhPe LUZ Z gh of s LL L n 2722 ULL ZALE UTILI s 7 p APP AD 24 7 LAA 7 2 2 L2 g 2 2 227 727 2 4 72721 s s oar an 22 77 2 4 2062257 2 4 A gg LLL LLL uu mE w a OOO K res E2777 5 evt 22244547 LP 7 22 22522 22 7 gura hhh 4 ps 77777 7777777 ei shin PELE DPE d d dut dad art mms Te rrt A ee eT TEELE EAA A A FP B SLOP pp pra 7 Dam mw mi ae gt 727227 proi eam vm mua ai fd di 4 al um 5542566 om reme FPE VE uut rr s 22225222402 my 7 v C LP 2222 22222222 m cada Ma b Lob 5 d od M d d j 1 1 Y 12 Better Basic Up until this point you may have felt quite confident about using ORIC You will be copying programs from books and magazines and probably starting to write your own original programs too This chapter is designed to help you improve your program writing and to make the most of the c
49. AT statement 157 Appendix K The 6502 monitor PROCESSOR PROGRAMMING MODEL 7 0 7 0 15 7 0 PCL PROGRAM COUNTER 8 7 0 He tee STACK POINTER i 7 0 PROCESSOR STATUS REG CARRY 1 TRUE ZERO 1 RESULT ZERO IRQ DISABLE 1 DISABLE DECIMAL MODE 1 TRUE BRK COMMAND 1 OVERFLOW 1 TRUE NEGATIVE 1 NEG T Oo Y Y YW QUT GT Y V 4 4 4 Y 41 4 41 41 P 1 ADC AND ASL Mak Oi d BCC BCS BEQ BIT BMI BNE BPL BRK BVC BVS CLC CLD CLI CLV CMP CPX CPY DEC DEX DEY EOR INC INX INY JMP JSR LDA da d da d Mi Ma d d d dj Wi di lI d i MACHINE INSTRUCTIONS Add Memory to Accumulator with Carry AND Memory with Accumulator Shift Left One Bit Memory or Accumulator Branch on Carry Clear Branch on Carry Set Branch on Result Zero Test Bits in Memory with Accumulator Branch on Result Minus Branch on Result Not Zero Branch on Result Plus Force Break Branch on Overflow Clear Branch on Overflow Set Clear Carry Flag Clear Decimal Mode Clear Interrupt Disable Bit Clear Overflow Flag Compare Memory and Accumulator COmpare Memory and Index X Compare Memory and Index Y decrement Memory by One Decrement Index X by One Decrement Index Y by One Exclusive OR Memory with Accumulator Increment Memory by One Increment Index X by One Increment Index Y by One Jump to New Location Jump to New Location Saving Return Address Loa
50. DDRESSES Perhaps you have wondered how ORIC can store numbers larger than 255 particularly as there are 65536 different memory locations Addresses are stored as two byte numbers e g Ist byte 2nd byte 128 is stored as 10000000 00000000 If the number is greater than 255 the second byte contains the number of 256 s in the number 125 0 RIC Manual e g 258 is stored as Ist byte 2nd byte 00000010 00000001 2 1 x 256 It may seem strange that the low order byte comes first but that is the order in which the processor decodes it So if you know a number is stored at locations 20345 and 20346 to calculate the number stored would require you to type PRINT PEEK 20345 PEEK 20346 256 ORIC saves you having to do this The instruction PRINT DEEK 20345 will do the same job as the line above DEEK stands for Double PEEK If you wished to change the number held in those two loca tions you would type DOKE 20345 N and N would be converted into a two byte number gt gt gt gt K gt K gt k KKK Sometimes it is useful to be able to use short machine code routines although the rest of your program may be written in Basic These can be totally original or you can borrow routines that are already written into ROM by PEEKing There are several commands in ORIC BASIC that allow you to do this CALL X where X is an address in memory transfers control to the address specified and begins the machine code rou
51. EPEAT 160 A INT RND 1 36 2 170 FOR P 0 TO 24 180 PLOT A P v 190 WAIT 4 200 PLOT A P 210 NEXT P 220 UNTIL SCRN A P 1 43 230 EXPLODE This program has been indented to make it easier to understand It will work perfectly well with the initial colons and spaces removed For a detailed explanation consult Chapter 12 To complete this section on low resolution graphics here is a program to show how background colours can be plotted in a circle 10 REM LORES COLOUR PLOTTING 20 LORES 0 30 STP 2 PI 50 40 R 10 X 10 Y 10 50 REPEAT 60 E 18 RND 1 6 37 ORIC Manual 70 PLOT X R SIN C Y R COS C E 80 C C STP 90 UNTIL C 2 PI 100 REPEAT UNTIL KEY gt 110 CLS eK gt gt SK E SK OK Kok HIGH RESOLUTION GRAPHICS If you want to draw high resolution pictures you need to type HIRES Try it now You should find that the top of the screen goes black leaving you just three lines for text at the bottom This is useful because you can type in drawing instructions and see the effect on the screen above In immediate mode you can therefore use ORIC as a drawing tablet to try out your instructions When they re correct you can incorporate them in your programs If you want to get back into TEXT mode just type TEXT and the screen will go back to its original format Both TEXT and HIRES can be used as commands within programs Before you start to draw anythi
52. IGHT DH DOUBLE HEIGHT ST STEADY FL FLASH GRA DOT GRAPHICS STD STANDARD CHARACTER SET ALT USER CHARACTER SET MM WM AJ VL MM ML M M 147 Cd M Appendix D A S C I I CODES decimal Code Character Code Character 32 Space 79 33 80 P 34 L 81 Q 35 82 R 36 83 S 37 84 38 amp 85 U 39 86 V 40 87 W 41 88 X 42 89 Y 43 t 90 Z 44 91 45 92 N 46 93 47 94 t 48 0 95 49 1 96 50 2 97 51 3 98 b 52 4 99 53 5 100 d 54 6 101 55 7 102 f 56 8 103 g 57 9 104 h 58 105 l 59 106 1 60 lt 107 k 61 108 62 gt 109 m 63 110 n 64 111 65 112 66 113 67 C 114 r 68 D 115 S 69 E 116 t 70 F 117 u 71 G 118 v 72 H 119 w 73 I 120 X 74 J 121 y 75 122 2 76 L 123 77 M 124 78 125 148 y 001417417 1T 4T Y 1T 1T IT 0T IT 1T 0T 1T T U il Appendix E Binary Hex Decimal conversion table m a BINARY BINARY MN 1 ON Q UC amp 00000000 00000001 00000010 00000011 00000100 00000101 00000110 00000111 00001000 00001001 00001010 00001011 00001100 00001101 00001110 00001111 00010000 00010001 00010010 00010011 00010100 00010101 00010110 00010111 00011000 00011001 00011010 00011011 00011100 00011101 00011110 00011111 00100000 00100001 00100010 00100011 00100100 00100101 00100110 00100111 00101000 00101001
53. IN in line 50 to COS and see the difference while ORIC plots a COSINE curve PROG 2 Tower 5 REM TOWER 10 HIRES 20 CURSET 20 20 3 30 DRAW 0 1601 40 DRAW 200 0 1 50 DRAW 200 160 60 CURSET 25 170 3 70 A T TOWER 80 FORN ITO6 90 CHAR ASC MID A N 0 1 100 8 0 3 110 NEXT 120 CURSET 200 170 3 130 CHAR ASC X 0 1 140 INPUT DISTANCE D 150 INPUT ANGLE X DEGREES X 160 XR 57 29578 170 TAN XR D 180 PRINT H This calculates the height of a tower if you can supply the distance and the angle from your position to the top of the tower Lines 30 to 74 am a ar adr a aa ut i 4 d V aura 4 4 4 4 d 4 4 4 al 4 U 4 4 uU U Chapter 7 More mathematical functions 50 draw the triangle lines 70 to 110 are necessary to print on the high resolution screen and line 160 converts degrees to radians Note the semi colon in line 180 This keeps the answer in view on the text window There is a list of derived functions in the Appendices You can define these using DEF FN or by use of the defined amp character see the Machine Code chapter as an extension function 79 Words CHAPTER 8 T T 19 L IL IE IL IC 8 Words Earlier we discovered that computers can manipulate any collection of symbols not just numbers So that ORIC knows that the symb
54. M S 60 DATA 1 3 8 6 4 Line 20 READs the DATA one item at a time and assigns that value to the variable A It is added to S initially zero each time and printed out at line 50 When the program is RUN a pointer moves along each item as it is READ and it remains at the last item it reaches If you type in GOTO 10 the pointer is not reset and you will get an OUT OF DATA error message RESTORE is a command that resets the pointer in a program Add 15 RESTORE and see the effect this has on the program The pointer is reset to the first DATA item each time the loop is executed so 1 is added to S each time and the rest of the DATA is ignored gt gt gt gt gt K gt K gt K gt ARRAYS Sometimes it is a better idea to collect similar variables together instead of giving them different names Arrays have brackets following the variable letter so you can identify an element e g N N 2 N 3 and N 4 are all elements in the array N Oric reserves space for up to 10 elements in an array automatically If you require more room you will have to use the DIM statement e g DIM N 14 will reserve space for 15 elements Arrays start with zero not one in most forms of Basic 9 0 RIC Manual One reason for using arrays rather than simple variables 15 that they can fit in FOR NEXT loops easily 10 FORN 1 05 20 A N 30 NEXTN 40 FORX ITOS5 50 PRINT X A X 60 NEXTX Lines 10 to 30 load the array
55. M TUNE 20 FORN 1TO11 30 READ 40 MUSIC2 3 A 0 45 PLAY3 0 7 2000 50 WAIT B 60 PLAY 0 0 0 0 80 NEXT N 100 DATA 5 30 5 30 7 30 8 75 5 75 110 DATA 8 60 10 30 7 60 5 30 3 30 5 180 Although MUSIC and SOUND are fairly easy to imagine in terms of the sounds they will produce PLAY is more difficult This program allows you to enter the different channels 1 2 and 3 and also to alter the two envelope parameters mode and period In this way you will soon become familiar with all the sound commands that ORIC has to offer 5 REM ENVELOPE TEST 10 INPUT ENTER THE TONE CHANNEL 12 3 20 IF T lt 1ORT gt 3 THEN 10 30 INPUT ENTER THE ENVELOPE MODE 0 TO 40 IF M 0 OR M 7 THEN 30 50 INPUT ENTER THE ENVELOPE PERIOD 0 TO 327677 101 ORIC Manual 102 60 80 90 100 110 120 130 1 8 lt 0 OR P 32767 THEN 50 PRINT CHANNEL T PRINT ENVELOPE MODE M PRINT ENVELOPE PERIOD P MUSIC 3 4 0 PLAY T 0 M P PRINT PRESS RETURN IF SOUND CONTINUES pje Jil TTA a arm m n CHAPTER 11 Saving programs tape LA Lf ML F7 77 ZZ BU 7777 SM 2 2 5 4 46 2 m T T q T T T T T F X T I F b di bb 4d d db ob d DoD di 11 Saving programs on tape When you have spent some time typing in a long program it s nice to know th
56. MP Oper X Indirect X 2 indirect Y 2 D1 See erie au 2 a NZC CPX Oper Immediate 2 EO CPX Oper Zero Page 2 E4 CPX Oper Absolute 3 NZC CPY Oper Immediate 2 co CPY Oper Zero Page 2 C4 CPY Oper Absolute 3 CC T T pee NZ DEC Oper Zero Page 2 C6 DEC Oper X Zero Page X 2 D6 DEC Oper Absolute 3 CE DEC Oper X joues 3 DE i SE NZ DEX Implied 1 E E L 8 e 1 E DEY Implied 1 88 161 ORIC Manual Perea sete 21 1 Assembly HEX Processor Name Operation Language Addressing i No OP Status Reg Description Form Mode ytes Code Codes E a ges 1 EOR NZ Exclusive OR memory A V MA EOR HOper Immediate i 2 49 with accumulator EOR Oper Zero Page 2 45 Oper X Zero Page X 2 55 EOR Oper Absolute 3 40 EOR Absolute X 3 50 Oper Y Absolute Y Br n 159 EOR Indirect X 2 EOR Indirect Y 205 1 dea A ee 4 y oer 4 gt 4 i 2 vs NZ Increment memory gt M INC Oper Zero Page 2 E6 by one INC Oper X Zero Page X 2 F6 Absolute 3 EE INC Oper X Absolute X 3 _ FE rc Mese m HE eee e 2 INX NZ Increment index X by one X X INX Implied l E8 ess Pints Wie a a ee H INY N
57. N 26 N A 60 NEXT N 70 WAIT 500 80 CLS 5 REM ALT CHARS IN LORES 0 10 LORES 0 20 A 9 HELLO CHR 8 30 FOR N 2 TO 24 40 PLOT N N KKKK 50 PLOT N 26 N A 60 NEXT N 70 WAIT 500 80 CLS gt K gt gt gt gt gt K gt K OK gt SCREEN POSITIONS If you need to know which characters are at a particular position on the screen in either TEXT or LORES modes use SCRN X Y Type CLS to clear the screen The cursor should now be at the top left hand corner Type PLOT 10 20 A capital A will appear near the bottom of the screen 36 il jj HP O J J I JD H PPE H H j H H iH 1 H H dl 4 sb 1 G AP B3 A A A J Bb 4 X Chapter 4 Colour and Graphics lype PRINT SCRN 10 20 The number 65 will be returned as this is the ASCII code for the letter A Here is a short program that REPEATS a loop until a falling missile reaches a target SCRN X Y detects when the missile is one place away from the target the Ascii code for is 43 see line 220 and the program finishes with an explosion After you have RUN the pro gram change the mode in which it operates by adding line 115 LORES 0 or 115 LORES 1 This will show you the different effects you get according to the mode you have selected 100 REM USE OF SCRN X Y 110 CLS INKI PAPER4 120 FOR N 20 TO 25 130 PLOT N26 140 NEXT 150 R
58. NE 89 ORIC Manual 40 GET C 50 PRINT C 60 C ASC C 70 A 46080 D C 8 80 GOSUB 1000 90 PRINT ENTER THE DATA 100 FORN 0TO7 110 PRINT ROW 120 INPUT X N 130 IF X N gt 63 OR X N lt 0 THEN 120 140 POKE D N X N 150 NEXT 160 GOSUB 1000 200 STOP 1000 REM CHARACTER GEN SUBR 1010 FORN 0TO7 1020 X N PEEK A D N 1030 FORM 0TO7 1040 Y N M INT X N 2 7 M 1050 2 X N 2 7 M Y N M 2 7 M 1060 X N Z 0 0001 1070 IF Y N M 0 THEN POKE 48220 N 40 M 32 1080 IF Y N M 1 THEN POKE 48220 N 40 M 128 1090 NEXT M 1100 NEXT N 1110 RETURN gt 2K gt SK OK OK OK KK SERIAL ATTRIBUTES To send information to the screen ORIC uses serial attributes This means that a byte sent to the screen can be considered as a graphic pattern or as an attribute controlling colour flashing etc The way the bits are set determines whether the byte is read as an attribute or not If bits 6 5 are both zero then the remaining 5 bits are considered as an attribute there are 32 of these If bits 6 5 not both zero then bits 5 to 0 are read as a pattern In HIRES mode bits to 5 are the pattern bits In TEXT and LORES mode bits 0 to 6 are the ASCII look up codes Control codes bits 6 5 set to 0 become attributes Bit 7 controls whether the character is inverse or not 1 is on O is off 90 AT AT UT aa adriana 14 L 4 5 4 r
59. R X X 1 Inverse hyperbolic tangent ARGTANH X LOG I X 2 Inverse hyperbolic secant ARGSECH X LOG SQR X X 1 1 X Inverse hyperbolic cosecant ARGCSCH X LOG SGN X SQR X X 1 1 X Inverse hyperbolic cotangent ARGCOTH X LOG X 1 x 1 2 A Mod B MOD A INT A B INT A B B 0 05 SGN A B 153 gk yk gh 13 ih ih i AT A dl df A dl dM d H SSd W S32I77 ANY 53307 XAL dvi SV Y NY SIDIG WW ETI IO SivX3 SALWNIT2HO 02 X S34vwNIOSO Q A 154 Appendix H Text Screen Map 532018 Wa qvid NAZIS High Resolution Screen Map 5 Appendix IR TE CE TY B TE THE TH THES TES Ve oT TE Appendix J Error Codes If ORIC cannot handle a command or some information then an error message will result It will be followed by the line number where the error occurred if it was in a program These are the possible codes and their meanings 1 2 3 4 5 6 7 8 9 10 11 12 156 CAN T CONTINUE Attempt to continue a program after a line has been added or deleted DISP TYPE MISMATCH Attempt to DRAW in TEXT mode or similar problem DIVISION BY ZERO Difficult even for ORIC FORMULA TOO COMPLEX More than two IF THEN statements in the same line ILLEGAL DIRECT A statement such as DATA or INPUT has been used as a
60. RINT N CHR Q7 T CHR N 30 PRINT 40 WAIT 25 50 NEXT N You can use this program to select characters to form your own graphics shapes This is one way in which it can be used 1 REM MONSTER 2 REM LORES DEMO 5 LORES 1 6 D 0 9 REPEAT 10 A F9 B 61 20 FOR C 0 TO 35 30 PLOT C D A 35 PLOT C D LB 45 PLOT C D 50 PLOT C D 1 55 NEXT C 56 SHOOT 60 D D 2 70 UNTIL D 26 75 EXPLODE 80 CLS The characters in A and B do not appear in their normal form as LORES 1 has been selected The rest of the program sends the composite character along the rows successively until row 26 is 35 0 RIC Manual reached when it will explode To see the standard characters simply type LORES 0 in line 5 Should you need to mix alternate and standard characters on the same screen i e to mix text and graphics then it is easy To use stand ard characters in LORES 1 CHR 8 will switch to the standard set and CHR 9 will switch back If you use them in reverse you can of course print alternate cha racters in LORES 0 Here are two programs to demonstrate this effect In all programs using LORES 0 or LORES 1 it is a good idea to switch off the flashing cursor by typing CTRL and Q at the same time Repeating this action will switch the cursor back on 5 REM TEXT IN LORES 1 10 LORES 1 20 AS CHR 8 HELLO CHR 9 30 FOR N 2 TO 24 40 PLOT N N KKKK 50 PLOT
61. This saves having a cumbersome line later FNA actually calculates the series and is called at line 30 The loop goes up in steps of 4 starting with 3 so X is 3 7 11 15 etc This makes correct increments and the result is printed at line 50 If you RUN the program Oric will print a result for that gets closer and closer to the actual result Compare it with 3 1416 and you will see that it s not the fastest way to calculate even with ORIC To find r rather more quickly simply type PRINT PI This will give you an accurate value of m to several places Of decimals as PI is stored as a constant by ORIC Remember that this means you cannot choose PI as a variable name or indeed any word beginning with PI such as PIG 8 or PIPES 78 because PI is a reserved word 65 ORIC Manual Je Je Je lt lt lt lt lt RANDOM NUMBERS There is a useful function on ORIC that is often used in games programs This is RND which will return a pseudo random number Due to the way computers generate random numbers this wlll not be truly random and 1t would be possible to discover a pat tern in the series of numbers produced This is not likely to be obvious unless you perform a statistical analysis on the series so RND can for all normal purposes be considered truly random If you aren t sure what random num bers are then consider a die It has an equal chance of producing any numbers from 1 to 6 The order in which the num
62. W variables Branches to subroutine at Nth line ON N GOSUB number specified 2000 3000 Branches to Nth line number spe ON N GOTO cified 1000 2000 Changes background colour of PAPER N whole screen N is an integer 0 7 T 40 4T UT iT P Y Y um um um am um jT aT Tut p mmn BE PATTERN PEEK PI PING PLAY PLOT POINT POKE POP POS PRINT PULL READ RELEASE REM Chapter 15 ORIC Basic Sets the pattern register for PATTERN X DRAW commands X is an integer O 255 Returns the contents of memory PEEK X location X Returns the value 3 14159265 PRINT 2 PI Produces predefined sound PING See Sound chapter Plots a character on the LORES PLOT X Y X TEXT screen using X Y co PLOTX Y A ordinates Returns 0 if the specified pixel is POINT X Y background and 1 if the pixel is foreground X is absolute X value 0 239 Y is absolute Y value O 199 Stores value V in memory location POKE N V N isan integer 0 255 Causes one RETURN address to POP leave the stack of RETURN addresses The next RETURN encountered after the POP bran ches to one statement beyond the second most recently executed GOSUB Returns the current horizontal A POS position of the cursor Prints numbers variables and PRINT strings on the screen HELLO may be used instead of PRINT PRINT N A Pulls one address from the stack PULL in REPEAT loops See POP Reads ne
63. Z Increment index Y by one Y Y INY Implied 1 C8 Ho eee 4 99 e 4er t JMP Jump to new location PC 1 PCL JMP Oper Absolute 3 4C PC 2 gt PCH JMP Oper Indirect 3 6C bloc Mem cr MEE VET dE cmd o tms pki upset A JSR Jump to new location PC 2 JSR Oper Absolute 3 20 saving return address PC 1 PCL 2 gt PC B o eee LDA NZ Load accumulator M gt LDA Immediate 2 A9 with memory LDA Oper Zero Page 2 AS LDA Zero Page X 2 BS LDA Oper Absolute 3 AD LDA Oper X Absolute X 3 BD LDA Oper Y Absolute Y 3 B9 LDA Indirect X 2 Atl LDA Oper Y Indirect Y 2 BI oa 3 ts NE Mis N ptt LDX NZ Load index X M gt X LDX HOper Immediate 2 A2 with memory LDX Oper Zero Page 2 A6 LDX Oper Y Zero Page Y B6 LDX Oper Absolute 3 1 AE LDX Oper Y Absolute Y 3 BE M T E E 4 c Apo 2 m 4 LDY NZ Load index Y M Y LDY HOper Immediate 2 with memory LDY Oper Zero Page 2 1 A4 LDY Zero Page X 2 B4 LDY Oper Absolute 3 AC LDY Oper X Absolute X 3 BC _ 2 ies Rast ni 162 Y J y 1 i Name Description LSR Shift right one bit memory or accumulator NOP No operation ORA
64. age X 2 75 ADC Oper Absolute 3 60 ADC Oper X Absolute X 3 70 ADC Oper Y Absolute Y 3 79 ADC indirect X 2 61 ADC Oper Y Indirect Y 2 71 es AND NZ AND memory with AND Immediate 2 29 accumulator AND Oper Zero Page 2 25 AND Oper X Zero Page X 2 35 AND Oper Absolute 3 20 AND Oper X Absolute X 3 30 AND Absolute Y 3 39 AND One Indirect X 2 31 AND Oper Y Indirect Y 2 31 MIL SE oa T ASL NZC Shift left one bit ASL A Accumulator OA ASL Oper Zero Page 2 06 ASL Oper X Zero Page X 2 16 ASL Oper Absolute 3 OE ASL Oper X Absolute X 3 IE k L T 4 1 e BCC Branch on carry clear Branch on C 0 BCC Oper Relative 2 90 mer pe E i i BCS Branch on carry set Branch on C 1 BCS Oper Relative 2 80 F t T T T 1 Branch on result zero Branch on Z 1 BEQ Oper Relative 2 FO eu E BIT M M Z Test bits in memory M N Bit Oper Zero Page 2 24 with accumulator M V BIT Oper Absolute 3 2 1 4 BMI Branch on result minus Branch on N 1 BMI Oper Relative 2 30 2 4 4 BNE Branch on result not zero Branch on Z 0 BNE Oper Relative 2 DO sath 4 BPL Branch on result plus Branch on N 0 BPL Oper Relative 2 10 L i t D BJ Force Break Forced BRK Implied 1 00 Interrupt
65. am add on a small number for safety unless you are really pushed for memory and subtract the total from the number you previously found Then enter HIMEM X where X is the new top of user memory you have just calculated If you wish to learn more about using 6502 machine code then there are several books which cover the subject in great detail Some of the more useful ones are written by Rodnay Zaks published by Sybex and Lance Leventhal published by Osborne McGraw Hill Other information and books can be obtained from Rockwell International themselves 129 ing a printer CHAPTER 14 Us x EL EE H HH T CBRL CRD CR h P F OR P t F tE t f T F 404 3 a Y J di jd j iba j h d ih d j 1 dl dp d Ah hh h 14 Using a printer Oric may be used with any printer that has a Centronics interface As well as the printer you will need a connecting cable The printer connection is located at the back next to the expansion port The printer should be connected before switching on If all is well the printing head should align itself at the starting position as soon as power is supplied In addition to the instruction booklet with the printer you may find the following information helpful On first connecting the printer run the following program 10 REM PRINTER TEST 20 FOR 255 30 LPRINT N CHRS N 40 NEXT N When you have entered the program ty
66. an be added to give the effects of bombs planes etc The possibilities are limited only by your ima gination and are not as complicated as they may appear at first sight Here are two short sample programs that will demonstrate some of the things you can do 5 REM MUSIC 20 MUSIC 1 RND D 6 RND 2 1 7 30 WAIT RND 1 20 5 40 GOTO 5 You can stop execution of this program by typing CTRL C To find out how it works see the later details that cover the MUSIC command The next program is a little longer but it gives you the opportunity to use ORIC as a keyboard instrument The keys on the top row act to produce notes a semi tone apart start at C and ending with the key Pressing will STOP the program Always include a PLAY 0 0 0 0 command at the end or the last note will continue until you hit a key 5 REM KEYBOARD 20 GET A 30 A VAL A 40 IF A THEN 11 50 IF A THEN A 12 60 IFAS THEN PLAY 0 0 0 0 STOP 70 IF A 0 THEN A 10 80 MUSIC 1 3 A 5 98 Ail i 0 PP j d pc id 4 J l ib id di 4 4 43 W Ww di 6 WX WX X Chapter 10 Sound 90 GOTO 5 Line 20 waits for an input form the keyboard Line 30 reads the value into variable A If you press a number then A will be the value of that number if another key then A will equal 0 Lines 40 to 60 convert the remaining keys to the required values Lie 70 stops A from be
67. an do to make your programs easler to read Use REM statements to explain lines REM stands for remark and is ignored by ORIC It is only there for your benefit when reading through the listing or for when you show the program to others This will show how you can use REM 10 REM COPYRIGHT F BLOGGS 20 FORN 1 TO 10 REM COUNTS LOOP 30 PRINT FRED IS MAGIC 40 NEXTN 29 ORIC Manual 50 END 60 REM THIS IS A RATHER SILLY PROGRAM Use REM statements to label your subroutines Note that you can have have more than statement on a line but each statement must be separated by a colon See line 20 1000 REM SUBROUTINE TO WAIT FOR A SHORT TIME 1010 WAIT 100 1020 RETURN You can use instead of REM but only as a comment at the end of a line 10 PRINT HELLO THIS SAYS HELLO is permissable 10 COPYRIGHT ORIC LTD is not permissable Basic isn t hard to learn and this is only a brief guide You will become more proficient the more you use it gt K gt gt gt gt gt F gt K I hear and I forget I see and I remember I do and I understand Old Chinese proverb 30 1 1 43 d d d d G di ii 43 d d d d d dii CHAPTER 4 Colour and Graphics BM d bd dh dd d b b L ll i di d 4 d d di d di 4 Colour and Graphics When you switch ORIC on it automatically goes into TEXT mode i e you
68. at you can store your program away somewhere and load it into ORIC or another ORIC at a later stage You will need a cassette recorder and a connecting lead to do this As mentioned previously the plugs depend on the type of recorder you have ORIC has a 7 pin socket at the back for cassette input output If your recorder has a remote socket it can be con nected to the extra pins If not don t worry a 3 pin DIN plug should fit but you will have to remember to switch the machine on and off yourself or use the PAUSE button Do not attempt to use a 5 pin DIN plug as the outer pairs of pins are usually shorted together and will not function on ORIC To save a program switch the recorder on to record and type CSAVE XX XX is the name you give to your program and may be up to 17 cha racters in length and include full stops hyphens etc When you press RETURN the program will be converted into sound signals and recorded on the tape The message Saving XX will appear on the status line When the program has been saved Ready will appear on the screen To load the program back in make sure the recorder is connected properly and type CLOAD ORIC will search through the tape until it reaches program XX and will then load it into internal memory While it is searching the message Searching will appear on the status line When the required program has been found the message will change to
69. ation much easier I17 ORIC Manual Disadvantages 1 Structured programs may use more memory 2 The speed of the program may be reduced 3 The hardware of the computer may not be used in the most economical manner 4 It is harder to learn to write good structured programs than it is to pick up sloppy habits Mug trapping Writing structured programs may make you a better programmer but it is no guarantee that your program is as good as it could be When you test your pi ce de r sistance then if it is designed to be used by others it is important to consider all the silly things they may decide to enter If you ask for a number to be input what happens if a user enters two instead of 2 What happens if they press RETURN without entering anything Luckily ORIC is kind to errant users In the first instance a string being entered instead of a number REDO FROM START will be printed until a figure is input In the second case ORIC will wait until something is actually entered If RETURN is constantly pressed then the question mark prompt will constantly re appear You can make your requirements easier for the user to understand If you check the ASCII code of the input or the value of a number then a message telling the user what to enter can be built into your program 10 INPUT ENTER THE YEAR AS 20 IF VAL A 1900 OR VAL A gt 1985 THEN PRINT BETWEEN 1900 amp 1985 PLEASE GOTO 100
70. bers are actually produced in a series of throws is random To simulate this on ORIC try this program 5 REM DICE THROWER 10 FORN ITOIO 20 PRINT PRESS ANY KEY TO THROW DIE 30 GET A 40 A INT RND 6 1 50 PRINT A 60 NEXT Line 20 waits for any key to be pressed Line 30 chooses a random number between 0 1 multiplies it by 6 the INT function loses any decimal fraction and finally 1 is added This ensures that a number from 1 to 6 will be produced RND n will produce a random number greater than or equal to 0 and less than 1 if n is a positive number If n is a negative number then the random seed is set to a particular number and subsequent positive n s will always produce the same sequence If n is zero the last random number generated will be produced gt gt gt K gt gt K gt gt k gt F gt F To conclude this chapter here is a program that utilizes many of the functions mentioned In this chapter It also uses some string handling routines that you may not fully understand until you have read the relevant chapter If necessary come back to it later Calendars are difficult to construct due to the awkwardness of the earth in not taking an exact number of days to pass round the sun In fact it takes 365 242216 days to make an exact year 66 J IT m PP Jo iy j I m y jm Im m Im n n n n mum de 1 e 1 de XE 1 11 M Chapter 6 Number crunching Various people
71. can be Use of REPEAT UNTIL FOR NEXT and IF THEN ELSE will help you avoid falling into a tub of spaghetti Here then is the completed curve stitching program It is not offered as the most wonderful program ever written simply as an example of how the use of loops REMs and indenting can improve the look of a program 1000 REM CURVE STITCHING 1010 REM 115 ORIC Manual 116 1020 1030 1040 1050 2000 2010 2020 2030 2040 2050 3000 3010 3020 3030 3040 3050 3060 4000 4010 4020 4025 4030 4032 4034 4035 4036 4040 4045 4050 4055 4060 4065 4070 4080 4090 4100 4110 4120 5000 COPYRIGHT A J S REM 1 83 CONTROL MODULE GOSUB 3000 INITIALIZATION 4000 INSTRUCTIONS GOSUB 5000 MAIN PROGRAM STOP REM REM INITIALIZATION REM INKI PAPER 4 SIZE 160 INSTRUCTIONS CLS B L CURVE STITCHING PRINT CHR 27 B PRINT PRINT PRINT PRINT PRINT This program will draw lines from PRINT each side of a square to adjacent PRINT sides The step size is the distance PRINT each line is from its neighbour PRINT As each set is completed the square PRINT will be redrawn with the step size PRINT reduced by two PRINT PRINT Press RETURN to start A
72. culator or if you remember your geometry lessons at school These are SIN sines COS cosines TAN tangents They are ratios of lengths of sides of triangles for difference angles SHOULOM T TRIANGLES BE IN THE Music SECTION P ABC is a right angled triangle x is the angle at corner ACB The side AB is opposite angle x BC is adjacent to angle x and AC is called the hypotenuse A AB _ op P oe ds tangent of angle x BC adjacent BD SP sine of angle x hypotenuse x BC adjacent cosine of angle x hypotenuse ORIC Manual You can probably see how the ratios change in these three exam ple triangles 1 When x is large adj 2 When x is 45 opp hyp odj 3 When x is small opp hyp adj TAN x opp gt adj SIN x opp gt hyp COS hyp adj SIN x op gt hyp COS x adj hyp TAN gt adj SIN opp gt hyp x COS x adj hyp a large number that tends towards infinity as x approaches 90 tends towards 1 as x approaches 90 tends towards as x approaches 90 a small number that tends towards 0 as x approaches 0 tends towards as x approaches 0 tends towards las x approaches 0 You can obtain TAN SIN amp COS by simply typing PRINT TAN x etc The ony problem is that Oric like most computers likes angles in radians not degrees Luckily degrees can be turned
73. d t 20 aNNOS ALLASSV Poy GND 2 I 915 SIAWON NOISNVdX4 SAE LL ee 1 1 X E i s Q AnadinQO AL lt lt 2 Sng Ja sse zi do st ou 0x 9n n 4 aP gl Go TP EL Ff R fp dp W 1P Gk t P Appendix G Derived Functions These functions are not directly available on Oric but can be defined using DEF FN e g DEF FN SC X COS X defines the secant Secant SEC X COS X Cosecant CSC X V SIN X Cotangent COT X I TAN X Inverse sine ARCSIN X ATN X SQR X X 1 Inverse cosine ARCCOS X ATN X SQR X X 1 1 5708 Inverse secant ARCSEC X ATN SQR X X 1 SGN X 1 1 5708 Inverse cosecant ARCCSC X ATN Q SQR X X 1 SGN X 1 1 5708 Inverse cotangent ARCCOT X ATN X 1 5708 Hyperbolic sine SINH X EXP X EXP X 2 Hyperbolic cosine COSH X EXP X EXP X 2 Hyperbolic tangent TANH X EXP X EXP X EXP X 2 1 Hyperbolic secant SECH X 2 EXP X 152 T iT PPT IP Y Y YU V Y Y uY W T d 4 Wd Wd Hi lh bt Mi 4 4 Mi Appendix G Hyperbolic cosecant CSCH X 2 EXP X EXP X Hyperbolic cotangent COTH X EXP X EXP X EXP X 2 1 Inverse hyperbolic sine ARGSINH X LOG X SQR X X 1 Inverse hyperbolic cosine ARGCOSH X LOG X SQ
74. d Accumulator with Memory LDX LDY LSR NOP ORA PHA PHP PLA PLP ROL ROR RTI RTS SBC SEC SED SEI STA STX STY TAX TAY TSX Index X TXA TXS Pointer TYA Appendix K Load Index X with Memory Load Index Y with Memory Shift Right One Bit Memory or Accumulator No Operation OR Memory with Accumulator Push Accumulator on Stack Push Processor Status on Stack Pull Accumulator from Stack Pull Processor Status from Stack Rotate One Bit Left Memory or Accumulator Rotate One Bit Right Memory or Accumulator Return from Interrupt Return from Subroutine Subtract Memory from Accumulator with Borrow Set Carry Flag Set Decimal Mode Set Interrupt Disable Status Store Accumulator in Memory Store Index X in Memory Store Index Y in Memory Transfer Accumulator to Index X Transfer Accumulator to Index Y Transfer Stack Pointer to Transfer Index X to Accumulator Transfer Index X to Stack Transfer Index Y to Accumulator 159 ORIC Manual INSTRUCTION CODES M mt E Assembly HEX Processor Name Operation Language Addressing No OP Status Reg Description Form Mode Bytes Code Codes 2 2 22 ts PO 1 4 SENA ADC NVZC Add memory to ADC Immediate 2 69 accumulator with carry ADC Oper Zero Page 2 65 ADC Oper X Zero P
75. direct command from the keyboard ILLEGAL QUANTITY Out of range parameter e g SQR 1 NEXT WITHOUT FOR Self explanatory one hopes OUT OF DATA Trying to READ past the end of the DATA list OUT OF MEMORY Self explanatory but might also be caused by more than 16 nested FOR NEXT TO loops or sub routines OVERFLOW A number larger than 1 70141 105 has occurred during a calculation REDIM D ARRAY Attempt to redimension an array previously dimensioned RETURN WITHOUT GOSUB Self explanatory T v y IY QT y Y qv P HIT UT UT VU JY Y JP D UT M uy MM MW MM WI W ee a Uu 1 i Yh Ma n YB Yi i Appendix J 13 STRING TOO LONG Strings must be less than 255 characters in length 14 BAD SUBSCRIPT An attempt has been made to reference an array element that does not exist e g LET A 24 25 Z when A has been dimensioned using DIM A 4 4 15 SYNTAX ERROR Incorrect punctuation or missing bracket etc 16 TYPE MISMATCH An attempt has been made to assign a string to a numeric variable Or vice versa 17 UNDEFD STATEMENT An attempt has been made to access a non existent line number using GOTO THEN or GOSUB 18 UNDEF D FUNCTION Attempt to use a function that has not been previously defined 19 REDO FROM START Attempt to enter a string when a number was requested Goes back to INPUTcommand 20 BAD UNTIL Control has reached an UNTIL without previously encountering a REPE
76. e screen is PRINT an integer O 255 SPC N HUM Returns the square root of N A SQR N Stops execution of a program STOP Converts a numerical expression N STR N into a string JIP 1T T Y T P P P Y Y Y m mmy WW AY M M 1 1 77 de ds Me TAB TAN TEXT TROFF TRON TRUE USR VAL WAIT ZAP Moves PRINT position N places from left of screen Returns tangent of angle N N must be in radians Switches to text mode Switches off trace function Switches on trace function Returns a value of 1 Passes value in brackets to a floating point subroutine See Chapter 13 Returns the numerical value of string N Conditional pause N 10 msecs Produces predefined sound Chapter 15 ORIC Basic PRINT TAB N HELLO A TAN N TEXT TROFF TRON USR N A WAIT ZAP 143 a 4 da My ha M M My h 1 We ay ML UL Hb Ua Appendix A ORIC 1 MEMORY MAP 40K HIRES MODE TEXT MODE FFFF FFFF ALTERNATE CHAR SET B800 STANDARD SCREEN ee CHAR SET THIS AREA NOT AVAILABLE FOR USER PROGRAMS USER PROGRAMS IUNLESS GRAB IF GRAB COMMAND ETIE A000 COMMAND IS ISSUED DIMENI CHAR SET RELEASE COMMAND STANDARD 9C00 ALLOWS HIRES MODE SS ah USER PROGRAMS USER PROGRAMS PAGE 4 UP TO 420 0500 FOR M C PROGRAMS PAGE 3 PHYSICAL ADDRESSES PAGE2 RUNTIME
77. each line at a time Line 10 clears the screen It also ensures that you start at the top of the screen You ll see why this is important when we add line 15 later Line 20 contains several statements CHR 4 switches on the auto double height to save typing everything in twice CHR 27 is A S C LI code for escape to start the escape character routine and the N in the quotes selects double height and flashing characters for the rest of the text it won t be printed itself Line 30 toggles the auto D H off Try changing the message in quotes as well as altering the escape code e g J HELLO will produce double height non flashing characters When you ve discovered how to achieve different effects add this line 15 PRINT then RUN the program From the strange result you will see how important it is to start on even line number 0 2 etc In conclusion here is a program that uses many of the high re solution graphics commands It also demonstrates how information for drawing commands can be held in DATA statements 44 V Im qm p p IP D IP iD IT IP GT IT P UP D QD iP D p p jp jp 1 Vier 3 D di 1 j 4 j d l l di hp 1 Y 1 4 i di i di dl Chapter 4 Colour and Graphics REM PENNY FOR YOUR THOUGHTS HIRES x 100 Y x CURSETX Y l PAPERG INKI1 CIRCLE70 1 s FRONT WHEEL CURSETX Y 3 DRAW69 SIN F 69 COS F F F
78. er 12 Better Basic module to call the subroutines This is the module that is written first 2000 REM CONTROL MODULE 2010 GOSUB 3000 INITIALIZATION 2020 GOSUB 4000 INSTRUCTIONS 2030 GOSUB 5000 MAIN PROGRAM 2040 STOP The program is now effectively written All that is necessary is for the subroutines to be filled in In practice you may find you have subroutines already written that will be suitable It is quite useful to build up a library of these At this stage you will find it helpful to use the computer to test the modules These will be introduced one at a time x k k k OK ok ck INITIALIZATION When you switch on ORIC all variables are set to zero This means that you do not need to give variables initial values if they need the value of zero in the program although it is a good idea to use names and letters that remind you of what they stand for e g SIZE 160 length of square in pixels Be careful you do not have two variables that start with the same two letters You must also avoid reserved words like KEY or LET which are already in Basic If you put REM statements at the beginning of subroutines and next to variables you will be able to see at a glance what they do e g I RND 1 7 REM CHOOSES INK COLOUR AT RANDOM 113 ORIC Manual Jc Jc Jc Jc Jc lt lt 3 THE MAIN MODULE When you reach the main section of the progam then if it involves graphics it is useful to s
79. f ferent ways so understand different instructions Internally the processor manipulates numbers stored as 8 bit binary digits Numbers are loaded into different memory loca tions and treated either as instructions or as data For instance if the 6502 receives the number 10101001 it understands this to be an instruction load a register or special memory store called the accumulator with the next number received The 6502 only understands 8 bit numbers ORIC allows you to enter decimal or hex numbers and converts them into their binary equivalent before sending them to the 6502 To make it easier to remember a short name is given to each 6502 instruction so in the previous example 10101001 or 169 decimal or A9 hex is known as LDA Accu mulator These memory joggers are called mnemonics To assist you in using machine code in ORIC there is a section in the appendices on 6502 mnemonics Although entering A9 into ORIC would be understood the mnemonic would not be recognised To make it clearer it could be added as a REM statement e g 100 DATA 9 20 LDA 20 To aid you in entering machine code programs it is possible to have a short program that will allow you to enter mnemo nics directly as well as variables data and addresses etc and it will decode this into machine language This is called an assembler program The user enters the mnemonics the source program and the assembler translate
80. find that you can use GOTO 10 without getting an error message 35 RESTORE Because it is in the loop the pointer will be reset each time and TOM will be loaded into all the elements of the array gt K gt F gt gt F gt gt gt K gt K gt SORTING To complete this chapter here is a program that demonstrates some of the string handling techniques of ORIC particularly the use of string arrays and string comparison There are many kinds of sorting methods that computers can use All operate on the principle that words starting with letters that have low ASCII codes will finish the routine at the beginning of an array those with high ASCII codes at the end and the rest arranged in numerical and therefore alphabetical order in between This sample program loads the words to be sorted into an array A and uses U as a temporary store while the list is worked through A is shuffled until the words are correctly ordered when they are printed out in lines 150 to 170 You could use this program as a sorting subroutine in your own programs and renumber it from say 2000 83 ORIC Manual 84 5 10 15 20 30 40 REM SORT INPUT NO OF WORDS N DIM AS N 1 FORX OTON 1 INPUT NEXT FORX OTON 1 PRINT A X NEXT FORK OTON 1 FORL K ITON IF A L gt A K THEN 130 U AS L A L AS K AS K U NEXT L NEXT K FORX 0TON PRINT NEXT um QT UT LT P UIT GT UT a T
81. first cha racter in the string is an alphabetic character then a value of zero is returned 10 A ORIC 20 V VAL A 30 PRINT V There is a function that works in the opposite direction STR con verts a numeric expression into a string 10 128 20 A STRS A 30 PRINT A You cannot tell the difference between PRINT A and PRINT A the results appear the same However PRINT A A will produce 256 whereas PRINT A A will produce 128 128 as ORIC treats them differently If you look at the end of this book you will find a table entitled ASCII codes These are also mentioned in Chapter 4 80 M3 41 d ilia aa AAA d d J 4 4 42 4 12 4 744 1 1 J VW hd J de 14 Chapter 8 Words Using the function ASC will return the code for any keyboard cha racter The function CHR works in the reverse direction and con verts a number between 32 and 128 into the corresponding character To list them all run this program 10 FORN 32 TO 128 20 PRINT ASCH CODE STANDS FOR CHRS N 30 WAIT 20 40 NEXTN Because all the characters have ASCII codes they can be sorted into order As you can see numerical order is the same as alphabe tical order so Z which has the value 90 is greater than A which has the value 65 You can use the greater than and the less than signs to compare strings as well as numbers Care must be taken however to avoid mixing
82. in the floating point accumulator the subroutine should do a JSR to D867 Upon return the integer value will be in locations 34 high order byte and 33 low order byte If you wish to convert an integer result to its floating point equivalent so that the function can return that value the two byte integer must be placed in registers A high order byte and Y low order byte If a JSR is done to D8D5 then upon return the floating point value will have been loaded into the floating point accumulator There are two other useful operations that ORIC can perform can be defined as a command that does not already exist in ORIC Basic amp X where X 0 to FFFF can be defined as a function that does not already exist in ORIC Basic The routines have to be written in machine code and loaded into a particular location in memory The start address is loaded as follows 127 ORIC Manual DOKE 2F5 address start address of routine DOKE 2FC address start address of amp routine To define to mean PRINT AT type 5 REM PROGRAM FOR EXTENSION CMD FOR PRINT 0 X Y JJJJ 10 REPEAT 20 READ DTA 30 POKE 400 CL DTA 40 CL CL 1 50 UNTIL DTA FF 100 DATA 20 96 D9 110 DATA AC FS 0 2 120 DATA C8 130 DATA 8 69 02 END OF PROG REM JSR GTVALS REM LDY GCOL REM INY REM STY CURCOL 140 DATA AS IF 150 DATA 4 20 160 DATA 85 12 REM LDA
83. inary i e 8 4 2 1 so half the line is on and half is off Try drawing the square again but this time reset the pattern mask to dif ferent numbers There is nothing to stop you having two sides con tinuous one dotted and one dashed To help you understand how it works just add this line as a starter 15 PATTERN 170 170 is 10101010 in binary It should send you UOI eee ne For a really exciting look at ORIC S capabilities in HIRES mode try this short program which generates interference patterns by drawing lines close to each other 5 REM MOIRE 10 HIRES 20 FORA OTOI 30 FOR B 0 TO 239 STEP 6 40 CURSET 0 199 A 3 50 DRAW B I99 398 A 60 CURSET 239 199 A 3 70 DRAW 199 398 80 NEXT B NEXT A cK 2K gt SK SK SK KK CHAR If you were to try to PRINT in HIRES mode you would only get text on the bottom 3 lines There is a command however that lets you print anywhere you like on the high resolution screen Type NEW to clear the memory then HIRES Now set the cursor to the middle of the screen by typing CURSET 120 100 3 Now type CHAR 65 0 1 You should have a capital A in the middle of the screen CHAR is the command and is followed by three parameters CHAR X S FB X is the A S C LI code 32 127 S is either standard character set or 1 alternate set FB is foreground background value 0 3 40 M dm uq P P qm ur JP IPP PIP p Ip pn un nn
84. ing 0 This would result in an error message as the note value in the MUSIC command cannot accept 0 as a valid parameter Here are the details of the sound commands 1 SOUND Channel Period Volume All the parameters must be numeric Out of range errors will be detected Channel 1 2 or 3 for tone channels 4 5 or 6 for noise channels Note that there is only one noise channel the 4 5 or 6 simply spe cify which tone channel it is mixed with Volume 1 to 15 fixed volume levels 0 variable volume level controlled by PLAY command SOUND can be used to produce a wide variety of both musical and non musical sounds Channels 1 2 and 3 produce pure tones and 4 5 and 6 add noise to each tone The period value controls the pitch the name refers to the period of vibration or frequency of the note do not mistake it for a note length parameter Unless you are using an external amplifer you will probably find that volumes of 6 or 7 are sufficiently loud 2 MUSIC Channel Octave Note Volume Channel 1 2 or 3 tone channels Octave 0 to 6 with 0 giving the lowest tone Note 1 Any other numbers will produce an error message 2 cH 3 4 D eB 6 F 7 FH G 99 ORIC Manual 9 G 10 ll 12 B MUSIC has been designed to offer you pure tones and the pitch has been set to make it easy to enter notes of a particular value e g from sheet music There are three available channels and notes oc
85. into radians and vice versa very easily 72 H dy aum ar 4 4 6 0 6 9 0 6 Chapter 7 More ma thema tical functions A quick recap on circles ext e diameter 2 x radius m circumference diameter T circumference 2 x radius circumference 2 x m x radius and radius circumference 2x How many times would the radius fit round the circumference More than 6 times in fact 2 x times If you were to cut out a slice from the circle so that the curved part equals the radius r then the angle at the centre x is 1 radian One complete circle 360 so 1 radian 360 57 29578 74 r To convert radians to degrees use the formula degrees radians x 360 radians x 57 29578 2n To convert degrees to radians use the formula radians 2 x n x degrees degrees 360 57 29578 Here are some programs to show how ORIC can use trigonometric functions to draw on the screen as well as calculate for you 73 ORIC Manual PROG 1 Sine waves 5 REM SINE 10 HIRES 20 DRAW 0 1991 30 CURSET 0 100 3 DRAW 239 0 1 40 FORA PITO PI STEP 0 02 50 CURSET A 38 120 SIN A 99 99 1 60 NEXT 70 PRINT SINE CURVE 80 GETA This draws a sine curve from m to Line 70 prints on the 3 line text screen and holds it until any key is pressed at line 80 Change S
86. ite the same as that spoken in New York If a Londoner talks about the pavement he means what an American would call the sidewalk This is why we have to speak correctly to ORIC or else we will be given error mess ages Type PRINT 5 then RETURN then type PRINT 5 then RETURN Apparently there s no difference Now type PRINT 5 2 then type PRINT 5 2 By now you should be used to pressing RETURN key so stop reminding you If you enter information in quotes it s called a string and strings can be letters numbers even graphics characters If you enter information without quotes then ORIC assumes it s a number and if it s in the form of a sum it will work out the answer for you Try PRINT 75 25 You should get 100 Hint you can type instead of PRINT to save time notice the difference between a zero 0 and a capital 0 and between one l and a capital I you know which is meant but ORIC has to be told correctly Try other calculations The subtract key is next to 0 divide is and multiply is shift 8 If you make a mistake press CTRL key and X A backslash will appear and the whole line will be deleted If you re interested in more complicated maths remember that ORIC does not operate on numbers as they arrive 19 ORIC Manual PRINT 4 3 2 will not give you 14 but 10 because is more important than Here is the order of priority most important at the top leas
87. ketch the finished display on paper and work out which values will keep the lines within the screen boundaries How will the display be built up It is possible to define each line on the screen one at a time but this is wasteful on memory and hardly elegant If you know the starting position of the lines and the step size it is better to use FOR NEXT loops In this program it is possible to use two FOR NEXT loops nested inside one another REPEAT pm FOR INCR 31 TO3STEP 2 FOR COUNT 0 TO SIZE STEP INCR E DRAW ROUTINE NEXT COUNT NEXT INCR UNTIL KEY lt gt These loops are held within a REPEAT UNTIL loop that con trols the repeat option Notice that the loops do not overlap and that you can only enter and leave each loop by one path There is another feature of ORIC that can be usefully employed here This is called program indenting Normally any leading spaces are lost by ORIC so if you enter 10 PRINT A the listing will show 10 PRINT A If however you enter a semi colon first there will be no difference in program execution but leading spaces after the semi colon will remain Using this feature you can indent all the loop structures in your program Although this takes more time the programs will be easier to understand Several of the programs in the manual are indented to 114 JH J H H H HI HOO iH I I IT I a HT D dd ll d VE Uh th W 1 i H FH M li dh j
88. machine code CHAPTER 14 Using a printer CHAPTER 15 Oric Basic A list of all Oric s Basic commands APPENDICES A Memory map B Control characters C Attributes D ASCII chart E Binary Hex Decimal table F Pin output chart G Derived functions H Text screen map I High resolution screen map J Error codes K The 6502 monitor Page 95 Page 103 Page 109 Page 121 Page 131 Page 135 Page 145 Page 146 Page 147 Page 148 Page 149 Page 151 Page 152 Page 154 Page 155 Page 156 Page 158 Page 165 un i A AN N N D qm m av iT im Y CHAPTER 1 Introduction dee Kay 2 DAMES Q O Q QU Q lt Q sS x sv lt qe BORNE A VLL V A e Q Iana Um ma aaa pee EIRE ee CN KS ys SEQ SESS ILLUD TL OTO TOT Te T T T h dd i 4 d do 41 odi d ad id od d idi 4 j d dl di 1 Introduction Congratulations You are the possessor of one of the most advanced micro computers available today This book will be required reading to those of you who have never used a computer before It will also be useful to anyone coming from other systems as ORIC has many features that make it more powerful than other machines If you are used to computers you may find it easier to skip through the next chapter You will learn a lot from
89. mportant one is the C P U Central Processor Unit which is ORIC s brain Microchips use high or low voltages to work If you imagine a row of eight light bulbs with switches underneath then you can see that any of them can be on or off You can think of the chips as all containing lots and lots of these eight block switches Each switch is called a bit and each block is called a byte If you think about it there are 256 different combinations of ons and offs If on 1 and off 0 then this is one way to store 256 numbers This system is called binary Binary Normal decimal 00000000 0 00000001 1 00000010 2 00000011 3 00000100 4 etc 11111110 254 11111111 255 This is why some eople think of computers as being only to do with maths in fact the zeros and ones can stand for letters or words or almost anything This is similar to the way morse code can say anything it likes using only dots and dashes Another important chip in ORIC is the BASIC ROM Read Only Memory This translates words in BASIC into zeros and ones that ORIC s brain can understand There are not very many BASIC 18 Wa 11 IL TIL TL IL d 11 L 11 11 Chapter 3 Programming in BASIC words somewhere between one and two hundred There are several different versions of BASIC around just as there are several dif ferent versions of English For example English spoken in London is not qu
90. n 2 3E 4 Make sure you understand these differences if you wish to understand how ORIC handles numbers gt K gt F gt gt gt gt gt gt k gt INT INT is a function that returns the largest whole number less than or equal to the value in brackets Try these to see if Oric returns the answers you expect PRINT INT 1 5 PRINT INT 2 PRINT INT 2 PRINT INT 1 5 Note particularly the result of the last example INT always rounds to a number less than that jn brackets unless it is already an integer ABS ABS returns the absolute value of a number If it is positive it remains so If it is negative it becomes positive Try these PRINT ABS 4 3 PRINT ABS 4 3 gt K gt F gt gt gt gt gt K gt K gt SGN SGN returns either 1 0 or 1 according to whether the value in the brackets Is negative zero or posttive Try this to see how 1t works 56 PP P T OI P p P T OP p UP IP Up p p M j th Uh Vay ll Chapter 6 Number crunching 10 FORN 5 5 20 PRINT N SGN N 30 NEXTN gt gt OK gt gt gt k gt K gt k gt DATA If you have a lot of numbers that will be used in a program then it is possible to have them stored in the program as DATA rather than have to type them in each time This short example shows how to incorporate this information in your pro grams 10 FORN 1 05 20 READ A 30 S S A 40 NEXTN 50 PRINT SU
91. n be produced by typing PRINT EXP X Therefore X EXP LN X IS THIS LOG z NATURAL 2 To find the logarithm of a number to another base use the formula LOG base z X LOGe X LOGe Z Log e is of course the same as LN on Oric oh KKK gt F gt k gt k ok ok NUMBER BASES So far we have encountered binary numbers and decimal num bers Perhaps you are confused by so many different ways of repre senting the same quantities In fact they are not really as difficult to grasp as they may appear it all comes down to how we choose to group numbers Normally we group things in tens probably 60 UT T UT UIT DG JP Jp HUP T T i TE Va Vi th Yb Va Y Ya Ti 14 Chapter 6 Number crunching because we have ten fingers and thumbs there is no other likely reason Our whole counting system uses groups of ten When we have ten groups of ten it forms a hundred and ten hundreds form a thousand and so on e g 3742 is made up of 3 thousands 7 hundreds 4 tens and 2 units The largest figure you may have in any column is 9 One more and you have enough for one group of 10 in the next column eg 9 1 10 Just suppose that humans had 8 fingers and thumbs They would have used these symbols 0 1 2 3 4 5 6 7 8 and 9 would not exist e g 7 1 10 The largest figure you may now have in any column is 7 One more makes a group of eight so the answer is 10 This is not read as ten but
92. ng you have to imagine that the screen is divided up into 240 positions labelled 0 239 across the screen and 200 positions labelled 0 199 down the screen Those across are called X positions and those down Y positions If you ve used graphs then you ll be familiar with this the only dif ference is that the origin 0 0 is at the top left hand corner There are several specialist drawing commands that make graphics easy on ORIC We ll go through them one at a time so you can see their effect CURSET sets the cursor to an absolute X Y position or will plot that point It must be followed by three parameters These are numbers that ORIC needs to know The HIRES cursor does not flash on the screen like the TEXT one 1 CURSET 128 108 1 will move the cursor to the centre of the screen and print a pixel or small dot The first parameter is how far across the screen O 239 the second is how far down the screen 0 199 and the third is the FB number FOREGROUND BACKGROUND 38 il 1 _ W pum Ip L h 4 4 di dod VO di Chapter 4 and Graphics The FB codes are background colour 1 foreground colour 2 invert colours 3 null do nothing Now type HIRES and experiment with CURSET The next graphics command is CURMOV This is similar to CURSET except that X amp Y are relative to the last
93. nual There are several ways in which you may make your program clearer to yourself and to others These are not hard and fast rules but they will undoubtedly improve your programming and also make it easier if you decide to move on to other languages such as Pascal or Forth First of all it is a good idea to write down your ideas for the program on paper rather than attempt to work them out at the keyboard This does not have to be in the form of a traditional flowchart indeed flowcharts should not be necessary for well designed programs Something simple to show the order of events is all that is needed As an example imagine that you have been asked to write a program that will demonstrate how straight lines can appear as a smooth curve This effect is often called Curve Stitching This is the effect The flow of control is like this RUN INITIALIZE gt INSTRUCTIONS gt MAIN PROGRAM gt REPEAT OPTION Instructions have been included so that anyone else using the program will know what it does and how to operate it Taking the needs of the user first is often termed an outside in approach Each section of the program will be written as a separate module and each module will be called as a separate subroutine in the order given above At the beginning will be a control 112 JO PPIP 4T LT P IT UT Y UT M IT 41 41 41 41 41 41 41 P 4d 4 od l d 4 Mj jll di di di di di di j di 4d d di 4 Chapt
94. numbers in DATA statements strings can be held just in a similar manner 10 FORX 0TO3 20 READ NAMES X 30 PRINT NAMES X 40 NEXT 50 DATA TOM TERESA DENIS MARTIN The DATA is READ one name at a time and stored in array NAMES NAMES 0 is then TOM 1 is TERESA NAME 2 is DENIS and NAME 3 is MARTIN String arrays are similar to numerical arrays ORIC reserves space automatically for up to 11 elements numbered to 10 If you want more then you must put in a DIM statement for the number you need e g DIM A 19 would create space for 20 elements There is one special thing to note about strings held in DATA lines If you insert leading spaces they will be ignored by ORIC e g DATA AB C DE will lose the space before the C If you want the space included you must surround the whole item by quotes e g DATA 82 AT dT IP dT aT dT dT dT dd jP 41 JP HU 41 ij aai 12 14 Up 11 p 3 11211111241 Ho d 2 I 11 Chapter 8 Words When you RUN a program the DATA pointer goes to the first item in the first DATA line and READS from there If you RUN the name program the data pointer will READ 4 items then stay at the end If you then enter GOTO 10 the pointer cannot find any more items so the error message OUT OF DATA IN 20 appears To send the pointer back in a program use the command RESTORE If you add this line to the program you will
95. of a program that does not work Type it in and RUN it 10 FORN ITO4 20 READ D 30 OND GOSUB 100 200 300 400 40 NEXT N 50 STOP 100 PRINT T 110 RETURN 200 PRINT AM 210 RETURN 300 PRINT 310 RETURN 51 ORIC Manual 400 PRINT THAT S WHO 410 RETURN 500 DATA 1 2 3 You will see that there is something wrong with the ON GOSUB line when it is compared to the DATA line If you enter 5 TRON then RUN the program the screen will fill with line numbers You can see that they never reach 400 and a check at the DATA line will reveal why it is missing a figure 4 If you only wished to examine say the working of a subroutine it would be possible to start the subroutine with TRON TRace ON and finish it with TROFF TRace OFF 52 Vy i p pu PU CHAPTER 6 Number crunching I T i nu thi Li IL ILi d ld obo TP Ub U 1 Id 6 Number crunching As you have already discovered ORIC can handle very large num bers and also very small ones both positive and negative The larger numbers grow the more figures they require so 10 needs two fig ures 100 needs three and so on This can become untidy and diffi cult to read and write when the number gets very large There is a way of writing numbers that is a lot more compact called scientific or exponent notation 10 be
96. ols must be con sidered as such and does not mistake them for variables they have to be enclosed within quotes 90 will result in zero being printed as it is considered to be a variable PRINT A will result in A being printed as it is enclosed within quotes String variables are identified by a dollar sign at the end e g A or A3 Remember that ORIC only reads the first two characters of a variable name so is the same as BIKES ALWAYS THOUGHT STRING BHANOUNG MEANT LEARNING THE CATS CRADLE Strings are assigned using LET although this is optional LET A HELLO is the same as A HELLO The only simple mathematical operator that may be used with strings is So 10 A HELLO 20 30 PRINT B will print HELLOHELLO 19 ORIC Manual Line 20 could not be written as B 2 A Total length of a string must not exceed 255 characters To find the length of a string there is a function called LEN IF A HELLO THEN PRINT LEN A will print 5 This value can be assigned to a variable 10 INPUT A 20 L LEN A 30 PRINT A CONTAINS L CHARACTERS Although a string cannot be used as anumber directly it is possi ble to convert it into a number using the VAL function 10 A 56 20 VzVAL AS 30 PRINT V Because V is not a string variable it can be manipulated as a number and PRINT 2 V will return a value of 112 If the
97. ome calculation This is easy using the ON command All you need to know are the expected results of the calculation and the relevant line numbers to branch to 50 INPUT CHOOSE 1 2 OR 3 X 60 ON X GOTO 100 200 300 70 PRINT NUMBER NOT CHOSEN STOP 100 PRINT 1 CHOSEN STOP 200 PRINT 2 CHOSEN STOP 300 PRINT 3 CHOSEN STOP Line 50 expects an input If X is 1 control branches to the first line number after GOTO i e 100 if X 15 2 it branches to the second line number i e 200 and if it is 3 it branches to the third number i e 300 If any other positive number is input the pro gram continues to the next statement following ON GOTO A similar command is ON GOSUB which will branch to a particular subroutine When the program returns it will continue from the next statement after the ON GOSUB gt KR KR gt SK ok SK gt F ok WHAT ELSE So far we have only used IF THEN in its simple form It is possi ble to extend its power by using ELSE Look at this 10 FORX ITO5 20 INPUT A 30 IFA gt 10THENPRINT TOO BIG ELSEPRINT 0 K 40 NEXT If the condition is true then the first command is obeyed if false then the command following ELSE If the program has not been told to branch then execution will continue from the next program line COMOITION AL ORANCH k k k k k k 28 T u o P ng M sd 1 1 P I
98. onsiderable facilities availa ble on ORIC The short example programs in this manual do not take up much memory When you switch on you are told how much memory is available for you to fill with programs Some of this will be used by the TEXT screen and rather more if you are in HIRES mode Some more memory will be used to store variables etc To find out the memory you have left type PRINT FRE 0 The number of bytes left will be printed If you write longer programs each time a string variable is used it is copied into an extra part of the memory This is par ticularly noticeable in long FOR NEXT loops or in nested subroutines If you start to run out of memory it may be useful to clear out all the extra copies after all only the most recent one is needed This is sometimes referred to as house keeping or as garbage collection Although a certain amount is automatic you can force garbage collection by having a line such as 240 A FRE in the necessary part of the program When you write small programs they are easy to compose at the keyboard Any problems are fairly easy to sort out and you can probably tell what the program does by glancing at the list ing With programs longer than about 20 lines or so this gets pro gressively more difficult and a week later you may wonder how you got it to work in the first place and to anyone else it may appear totally incomprehensible 111 ORIC Ma
99. osition 0 0 is at the top left hand corner of the screen The far left column cannot be used as it contains the attribute that controls the background or PAPER colour of that row The next column controls foreground or INK colour but may be used in TEXT mode If LORES 0 or LORES 1 are selected the screen is cleared to background black and the attribute for either standard or alternate character set is also placed on the far left of the screen LORES 0 uses the standard character set and LORES 1 the alternate set Try this 10 LORES 0 20 PLOT 16 12 HELLO If you run this short program HELLO will be printed in the centre of the screen You could use the program in Chapter 9 to define other character s using the standard character set The PLOT command would save you having to POKE into the screen memory 34 DSS e a i FG pg Su L 4 4 d d 1 4 di 4d d 4 Odi 4 di d L 1 1 Chapter 4 Colour and Graphics If you now type 10 LORES 1 If line 20 is still intact instead of HELLO appearing a strange set of blocks will be printed These are characters from the alternate set and these particular ones are those that share the same ASCII codes as the letters in HELLO This is the only difference between LORES 0 and LORES 1 This program will print out the complete set of alternate cha racters 5 REM ALTERNATE CHARACTERS 10 FOR N 32 TO 128 20 P
100. ou have entered it LIST it then RUN it and watch the screen This is total alien domination The only way to escape from them is to press ORIC s reset button when you will return to the standard character set 5 REM ALIEN DOMINATION 10 FOR X 46344 TO 47088 STEPS 20 FOR I O TO 7 30 READ M 40 POKE I X M 50 NEXT I 60 RESTORE 70 NEXT X 80 DATA 18 12 30 45 45 30 18 0 is a more useful program You can use it to redefine key board character upper or lower case A 2 dimensional array Y is set up to store the new character in its large form C is whichever key is pressed A is the start of the standard character set in memory D is the position of the first byte of the chosen character in the standard character set The subroutine at line 1000 PEEKs that byte of the character and converts the decimal contents of that byte into a binary number i e 45 would be converted into 00101101 and either zeros or ones loaded into the array Y The last section pokes either a solid block 128 if the cell is a 1 ora blank 32 if the cell is a 0 into the screen display This causes a large version of the character to appear on the screen The rest of the pro gram gives the user the opportunity to enter fresh data one line at a time and to examine the result in actual or enlarged size 5 REM CHARACTER GENERATOR 10 CLS 20 DIM X 8 DIM 8 8 30 PRINT PLEASE ENTER THE CHARACTER YOU WISH TO REFEFI
101. ou know you re in CAPS mode ORIC prints CAPS on the status line at the top of your screen There is lot of sense in this If you type run in small letters you ll get SYNTAX ERROR All BASIC commands and variables must be in capitals You can type anything into ORIC and press any of the keys and you will not harm the computer The worst that can happen is that you get into an endless loop or you manage to corrupt the screen if anything strange happens to the screen first press RESET If noth ing happens switch off the mains wait a few seconds and power up again You will get the initial screen picture ORIC will not complain but you might if you have to re type your program What happens when you grow fed up with a program and want to get rid of it Instead of switching off you can simply type NEW This will clear the memory and set all variables to zero Ke k k k ck k k LOOPS ORIC has shown us so far that computers are capable of making decisions according to whether conditions are true or false They are also capable of repeating an action for however many times you require For instance if you want ORIC to print all the numbers from 1 to 1000 and scroll them up the side of the screen you could type 10 PRINTI 20 PRINT2 30 PRINTS 40 PRINT4 But you d get rather fed up doing this 1000 times Luckily there is a BASIC command called the FOR TO NEXT loop that will repeat an instruction whilst it
102. pe LLIST This will list the program on the printer instead of on the screen If you do not get a listing but merely Japanese or graphics cha racters consult the printer handbook as to changing the character set in the printer When the listing is satisfactory run the program As you can see it consists of a simple loop that will LPRINT print to the printer rather than to the screen the number followed by the Ascii character that represents that code This will show you the character set available and just as importantly will show you which numbers are read as control codes on the printer Although these are standardised to a certain extent not all prin ters respond in the same manner The control codes determine actions such as line feed carriage return form feed character size etc For example Microline printers will print standard compressed or expanded characters If you were to type LPRINT CHR 1 133 ORIC Manual then subsequent characters on the printer would be twice their normal size very useful for headings etc LPRINT CHR 30 would result in a return to normal print LPRINT 12 results in a form feed on Dee writers The paper feeds through to the bottom of the page These codes are useful to know as they can be incorporated in your programs Many printers that have graphic characters will also dump the contents of the screen on to the printer which is a way to get a per manent record of
103. s this into a 124 JT TL TU 4 1 il 11 11 11 M ud uw CL bh dh idi 11 l Mi d do uUum hb u 4 P Chapter 13 Machine code programs machine code or object program A disassembler program works in reverse gt gt gt gt k gt gt k gt K gt F gt PEEK AND POKE How can we tell what is stored in any memory location You may remember coming across PEEK and POKE in previous chapters Type PRINT PEEK 48225 This is looking into the part of memory that is used to store the TEXT screen The number return is the decimal equivalent of the binary number stored at that location As this location is mapped to the screen area the number is the ASCII code for the character at that position To change that value type POKE 48225 128 You should be able to see which position on your screen 48225 controls as it will be filled with the character represented by ASCII 128 1 e a solid block If you look at the memory map in the appendix you will see what is stored at different locations You can try using POKE to put cha racters on the TEXT and HIRES screen This technique has already been used in the graphics chapter It is not a good idea to try to POKE into pages 0 to 3 0 to 1024 in decimal You can of course experiment as you will not damage ORIC whatever you enter gt K gt gt K gt K gt K gt gt gt K gt A
104. t important at the bottom A the power of Operators on the same line have the same priority This is a way of using ORIC as a calculator Enter these examples so you understand about priorities PRINT 2 3 4 PRINT 4 3 2 PRINT 4 3 2 PRINT 4 2 3 PRINT 2 3 4 PRINT 3 4 PRINT 3 42 PRINT 2 4 82 If you are uncertain then put the part of the argument equation you want calculated first in brackets e g 4 3 2 10 but 4 3 2 14 gt F OK gt OK OK OK gt F gt F gt F Do you remember I said that ORIC assumed everything without quotes was a number 20 1 1 WH WIP TP P UP IP H H IP TI H IP HU I UP IP IP IP IP UP UT H jq Ms 4 014 0 4 14 74 14 4 MM 14 14 11 Mi Mi 4 1 ET Chapter 3 Programming in BASIC Type PRINT H and see what happens You should get a Of course it can t be a number or can it Type LETH 4 Now type PRINT H This time ORIC knows that you ve set H equal to 4 just like in algebra H is called a variable ORIC will remember this until you either change the value of H or type CLEAR or switch off Try this with other letters then type CLEAR and see if ORIC has forgotten them You can use more than one letter so AB could have a different value to A or B You can also have A5 or A6 ORIC will accept varia bles of more than two characters in length but will only recognize the first two Try LET JOHN
105. tape CLOAD XX For additional tape commands see Chapter 11 CONT Continues execution of program CONT after break NOTE FB Codes FB is foreground background value Background 2 Invert 1 Foreground 3 Null do nothing 137 ORIC Manual COS Returns cosine of angle N A COS N N must be in radians CURMOV Sets the cursor to a new CURMOV X position X Y are relative to old position is 3 see below CURSET Sets the cursor to absolute CURSET X Y X Y position FB Note final position of X must be 0 to 239 and Y 0 to 199 in all graphics commands FB is 0 3 CSAVE Saves file name XX to tape DATA Stores a list of data that can DATA 1 2 be READ into variables BATH May include numeric and string ANGIE variables Leading spaces will be lost unless enclosed by quotes DEEK Returns the contents of byte plus DEEK 45610 256 times of the contents of next byte DEF FN Defines numeric functions DEF FNA Z 2 4 DEF USR Defines start of USR routine DEF USR 400 DIM Dimensions arrays Arrays are AS 10 5 predimensioned to 10 DOKE Stores value V in locations X DOKE X V and X 1 INT V 256 goes in X 1 and the remainder in X DRAW Draws a vector from current DRAW X Y FB cursor to current cursor plus X Y FB is 0 3 END Ends program END EXP Returns natural exponential of N A EXP N EXPLODE Produces predefined sound EXPLODE FALSE Returns a value of 0 FILL Fills A
106. tave from 1 to 7 and volume are all selectable If volume level zero is chosen on SOUND or MUSIC then the output is directed to the envelope section of the PLAY command Both SOUND and MUSIC are switched on by PLAY Note length can be controlled by WAIT statements and the sound is switched off by PLAY 0 0 0 0 3 PLAY Tone Enable Noise Enable Envelope Mode Envelope Period Tone Enable 0 No tone channels on Channel 1 On 2 Channel 2 On j Channel 1 2 On 4 Channel 3 On 5 Channel 3 1 On 6 Channel 3 2 On 7 Channel 3 2 1 On Noise Enable controls the routing of the noise channel and fun ctions as for Tone Enable Envelope Mode FINITE LENGTH CONTINUOUS i 100 1 p p m Dun n nin d di 1 dj di U ee oe Cee did dd ldi PI Chapter 10 Sound This controls the way the sound is produced i e repeating or rise and falling etc Envelope Period 0 to 32767 Controls how long the sound or note takes to start and end When you use the sound facilities on ORIC you may wish to turn off the keyboard click by pressing CTRL and F once If it is left on then key presses may affect the sound output This program illustrates one way in which note values both in terms of pitch and length may be held in DATA statements and called when required during the execution of the program A chord effect is achieved by opening channels 1 and 2 in the PLAY statement 10 RE
107. the instruction AUTO to the CSAVE instruction CSAVE PROG 1 AUTO There is no need to add anything to the instruction when an auto run program is CLOADed CLOAD PROGI will RUN immediately after loading as the AUTO message is encoded with the program on the tape 106 3 T T T T T IT T jT p IP P Pp p pup pp n lJ 3 j ob b DoDD i Y 1 1 i jJ 1 Y J J 3 1 1 1 3 Chapter77 Saving programs tape To save blocks of memory you need to know the Address where the block starts and where it Ends as follows CSAVE PROGMEM A 400 E 499 This would save the contents of RAM held from locations 1400 to 499 To load the block back type CLOAD PROGMEM A 488 E 499 Because the rest of RAM is unaffected it is possible to load in new character sets machine code programs etc without corrupting the Basic program You can also use this method to save the screen displays and load them back in at a later date Make sure if you use this method that you are in the same mode that the display needs or strange things may happen To save the TEXT or LORES screen type CSAVE NICEPICCY1 A48008 E49119 Note that you can use decimal or hexadecimal numbers for the locations All the additional commands may be used together in any order e g CSAVE AVON S A 41400 420 107 CHAPTER 12 Better Basic rom ms ra Aran 222 25 27172 7
108. their hexadecimal equivalent 10 FORN OTO255 20 PRINT 30 NEXTN gt i 3K i 2K 3K E gt k ok MATHS ROUTINES Although it is important not to think of computers purely as manipulators of numbers there is no doubt that they make many maths tasks that are usually boring and repetitive comparatively simple Oric has many built in routines that assist number crunching 63 ORIC Manual If you needed to know all the square roots from 1 to 100 you would have to spend a long time looking in tables or pressing calcu lator keys Oric can achieve this much more simply Type in this program 10 CLS 20 FORN ITOI00 30 PRINT N SQR N 40 NEXT N If you RUN it the numbers from to 100 will flash down the left side of the screen with their square roots next to them in the centre of the screen Oric calculates them so fast that you probably found it difficult to read Put in 35 WAIT 10 to slow the program down Oric can even calculate roots without using the SQR facility There is a method of finding roots called the Newton Raphson iterative method Iteration means to keep on doing the same thing again and again an ideal use for a loop on Oric Each time the guess is refined and gets closer to the correct answer This short program shows the guesses and stops when the answer is correct Line 80 jumps out of the loop if the guess is within 0 000001 of the right answer just in case there is not an
109. ther use for FOR NEXT loops is as a pause You probably found that ORIC prints so fast that you couldn t see the numbers To slow it down we can put in 25 FOR PAUSE 1 TO 100 NEXT PAUSE This is like saying Count up to 100 each time you print a number then continue Note the use of a colon to achieve two statements in one line Be careful about using this facility if there is an IF THEN branch in the line as if the condition is true then ORIC will jump to the new line and ignore any other statement in the original line An easier way to get pauses on ORIC is to use the WAIT command 25 WAIT N will delay execution of the program for N lots of 10 milliseconds ck ok k SUBROUTINES At this stage you may be wondering about sections of a program that occur several times but can t be achieved using simple FOR NEXT loops For instance in our counting program you might want to tell people that the wait between numbers was intentional You send the program to a subroutine where it waits prints the message then returns to the place where it left the main program 10 FOR X 1 TO 18 20 GOSUB 1000 30 PRINT X 40 NEXT 1000 PRINT THIS IS A SHORT BREAK 1010 WAIT 50 1000 RETURN gt K OK OK gt gt gt K gt F gt F ok ON GOTO Sometimes in the course of a program it s useful to be able to branch to different parts of the program according to the results of 21 ORIC Manual s
110. tine that is held there Return to Basic is accomplished when the routine reaches an RTS ReTurn from Subroutine Another way of accessing information from a machine code routine is to use DEF USR and PRINT USR The routine is written in machine code and the start address is entered by DEF USR start address If PRINT USR 0 is now entered the result of the routine is extracted from the floating point accumulator and printed Here is an example of how it can be used 126 JL TTA T TIT Uu 14 LL k 11 J 1 11 b b di l Bn B E tdi Chapter 13 Machine code programs 5 REM RAD DEG CONSTANT 10 FOR DISP 0 TO 12 20 READDTA 30 POKE 400 DISP DTA 40 NEXT DISP 100 DATA 9 07 LDA CONS7 LO 110 DATA AO 04 LDA CONS7 HI 120 DATA 4C 73 DE JMP MOVFM FLOAT 130 DATA 86 65 2E D8 CONSTANT180 PI RUN the program then type DEF USR 400 At any time PRINT USR 0 will print out the conversion constant for radians to degrees Here is a more detailed explanation of how it operates The value held in brackets after the USR function is actually passed to the floating point accumulator and a JSR to location 21 is per formed Locations 21 to 23 must contain a JMP to the beginning location of the machine language subroutine The return value for the function is placed in the floating point accumulator To obtain a 2 byte integer from the value
111. upper and lower case and all lower case letters have greater values than upper case so although apple is less than zebra apple is greater than Zebra To assist you in manipulating strings there are 3 more very useful functions RIGHT LEFT and MID RIGHT returns the right hand portion of a string as follows A ABCDEFGHIJ PRINT RIGHTS A 2 will print IJ The number 2 is the quantity of characters to be returned LEFTS returns the left hand proportion of a string as follows A ABCDEFGHIJ PRINT LEFT A 2 will print AB MID needs just a little more information 5 ABCDEFGHIJ PRINT MID A 5 2 will print EF The example means return the 2 characters from string A starting at position 5 The second number can be omitted 81 0 RIC Manual in which case all the characters to the right of and including the first number are returned A ABCDEFGHIJ PRINT MID A 5 will print EFGHIJ Here is a short program that demonstrates these functions 10 PRINT ENTER A STRING 20 INPUT A 30 IF LEN A lt 3 THEN PRINT TOO SHORT GOTO 10 40 PRINT A IS LEN A CHARACTERS LONG 50 PRINT IT STARTS WITH LEFTS AS I 60 PRINT AND ENDS WITH RIGHT A 70 PRINT AND HAS MID A 2 LEN A 2 IN THE MIDDLE Often itis easier to have information stored in a program Just as it is possible to hold
112. ween 2 93874x10 2 up to 1 70141x10 8 For further explanation see Chapter 6 Simple letters should be called floating point variables If the letter or pair of letters is followed by a then it is called an integer or whole number variable eg A 4762 These can be between 32768 and 32767 In general integer variables can be handled faster than floating point variables So far we ve only used ORIC to give us results in a simple way This is called immediate execution or calculator mode The usual way to use computers is to get them to store a sequence of instructions and to use this program when we require 22 WW pP ur p p qp up pP D DP JP Jp D IP qum G p ft di di i 43 4d Yd 4 4 4d 4 4i 1 1 v 1 5 1111 MW 1 Chapter 3 Programming in BASIC In BASIC the order of actions is controlled by line numbers It is usual to set the line numbers 10 apart so extra lines can be inserted later It doesn t matter in which order you enter the lines ORIC will sort them into the correct order automatically Try this short program 10 CLS 20 PRINT ENTER YOUR NAME 30 INPUT N 40 PRINT PLEASED TO MEET YOU NS ORIC will go to the first line number 10 and clear the screen PRINT Enter your name and then go to line 30 This says INPUT N so the program will halt here until you enter something and type RETURN N now contains your name ORIC will leap to line 40 and print
113. xt item in DATA list READ A N and assigns it to specified variable Assigns area described in GRAB RELEASE command to the HIRES screen Allows comments to be put in pro REM IGNORE gram lines Everything after REM THIS statement is ignored 141 ORIC Manual REPEAT RESTORE RETURN RIGHT RND RUN SCRN X Y SGN SHOOT SIN SOUND SPC SQR STOP STR 142 Creates a loop to repeat all pro gram lines up to UNTIL statement Tests statement in UNTIL statement If false repeats loop If true con tinues execution at next program line Sets READ pointer to first item on RESTORE DATA lines Returns the computer to the statement immediately after the most recent GOSUB Returns the right portion of a R RIGHT string N characters in length A N Returns a pseudo random A RND 6 number If X gt 1 then number is between 0 and 1 If X 0 then most recently generated number is produced If X lt 0 then number produced is the same for each X Executes a BASIC program from RUN 200 line N or from lowest line if N is not specified Also clears all varia bles Returns the ASCII code for the character at position X Y in LORES and TEXT modes RETURN Returns 1 if the argument is Z SGN X Y negative 0 if zero and 1 if pos itive Produces predefined sound SHOOT Returns sine of angle N SINN N must be in radians See Sound chapter Prints N spaces on th

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