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1. Toan D rea mia h ei ne a Pree pie x a Al a vos a TE pis ni ta rs ae fal e p Pi zi i hx ER aN F Fa te A gee tee beter a i ILN q oF Tan ah k ere a _ 8 Aap ist a e rere af E 54 a as oe parte POWER C is a disk based true C hanguage compiler for the Commodore computers iiir From spinnaker POWER Cis o disk based trae language compiler for the Commodore computers The use of the programming language amp one of the more important developments in the miero computer industry C i a simple and elegant programming language with an absence of restrictions and o generality thet makes i for more affective and convenient than other programming languages E combines the productivity of high level langueges with the control of kow level machine longuages P wos developed at Bell Lobs where it was used to program the populor UNIX operating stem For these reasons C has rapidly become a major computer programming hanguage and most Serious microcomputer software development today is being partormed im POWER C is a compact last and powertul language that is easier to use than BASIC Not only can programs be written more quickly in POWER C than in BASIC but they run more than ten fines faster Welcome to the future of programming POWER C DELIVERS Notre moching language object code which is more than ten fees foster tha2. prompt appears on your screen and with the POWER C System disk in your disk drive unit call the compiler program and tell it what source file you wish to compile by typing cc test c lt RETURND Compiler When the compiler asks you to insert your source disk just press lt RETURN gt because the source program test c is located on the system disk already in your disk drive unit Normally your source code would be located on a work disk which would be inserted at this time When the compiler is finished loading test c it will prompt you to insert your compiler disk Again just press lt RETURN gt because your compiler disk is already in the drive When the compilation of the test c source file is complete POWER C will ask you to insert your object disk Now is the time to use the formatted blank disk that you have ready Remove the system disk from the drive insert the blank work disk and close the drive door Now press lt RETURN gt and the compiler will write an object file called test o to the work disk Note that compiled object code filenames always end with the extension o lower case letter o not numeral 0 Now that the compiler has completed it s job it will return you to the Shell environment and the unique Shell prompt page 48 Optimizing The next step to optimize the object code and make it as small as possible is optional Normally we would not bother to optimize such a small object file but we will trim the
3. will direct the standard output to device 4 usually a printer A few programs adapted from examples in The C Programming Language book by Kernighan amp Ritchie are provided to illustrate these features sort n Sorts the standard input and writes the result to the standard output The n option indicates that the input is to be sorted in numerical order The default is alphabetical order actually lexicographic order find x n string Finds all occurences of the specified string in the standard input If the x option is specified only lines NOT containing the string are output If the n option is specified output lines will be numbered page 12 wfreq Counts the number of occurences of each word in the standard input A word is defined as a string of characters beginning with a letter and followed by up to 19 letters and digits As stated above programs that work with the Shell mini command interpreter must have file names ending with sh merely typing the name without the I O redirection specifiers These programs may be invoked by sh part along with any arguments and Once a program is loaded it may be run any number of times without re loading by using the built in run command EDITOR ed sh At the Shell program prompt type for the Commodore 64 in ed filename lt RETURND or if you want the syntax checking editor ced filename lt RETURN gt and the chosen editor will
4. getc getchar gets getw highmem hypot index See exit sin sin sin sin atoi bemp bemp hypot malloc floor open opendir sin sinh abs fopen ferror bemp getc gets printf putec puts malloc fopen scanf fread getc getc strcat page 18 For isalnum isalpha isascii iscntrl isdigit islower isprint ispunct isspace isupper Idexp log log10 longjmp malloc modf open open2 opendir peek poke pow printf putc putchar puts putw qsort random readdir realloc rewinddir rindex scanf setjmp sin sinh sprintf sqrt srandom sscanf strcat stremp strcpy strlen strncat strncmp strncpy sys tan tanh See isalpha isalpha isalpha isalpha isalpha isalpha isalpha isalpha isalpha frexp exp exp setjmp floor exp putc putc opendir malloc opendir strcat printf exp random scanf strcat strcat strcat strcat strcat strcat sin sinh NAME abs fabs absolute value SYNOPSIS abs i int i float fabs f float f DESCRIPTION Abs and fabs return the absolute value of their arguments NAME atoi atof convert strings to numbers SYNOPSIS atoi iptr char iptr float atof fptr char fptr DESCRIPTION Atoi converts the string pointed to by its argument into an integer Atof converts the string pointed to by its argument into a float quantity Both functions ignore leading spaces EXAMPLES char s in
5. let program use all available memory highmem Oxffff NAME hypot cabs calculate hypotenuse SYNOPSIS include lt math h gt float hypot x y float x y float cabs c struct float x y c DESCRIPTION Hypot and cabs return sqrt x x y y page 27 NAME isalpha ssi SYNOPSIS isalpha c DESCRIPTION classify characters The following functions return non zero integers if the stated condition is true zero otherwise isalpha isupper islower isdigit isalnum isspace ispunct isprint iscntrl isascii QQ aQa annaaana is a letter is an upper case letter is is is is is is is is yoo amp amp lower case letter digit letter or digit space or newline punctuation character printable character control character has value less than 0200 page 28 NAME malloc calloc realloc free memory allocation SYNOPSIS char malloc size unsigned size char calloc nelem elsize unsigned nelem elsize char realloc ptr size char ptr unsigned size free ptr char ptr DESCRIPTION Malloc returns a pointer to a block of memory containing at least size bytes Calloc returns a pointer to a block of zero filled memory containing at least nelem elsize bytes Realloc copies the block pointed to by ptr into a new block containing at least size bytes Ptr must point to a block allocated by malloc calloc or realloc Free releases the block
6. and will suppress the single drive prompts The designated work drive will be assumed to hold the source object disk and the system drive the the compiler disk link s address Run the linker If no arguments are given programs are linked in such a way that they will run under the Shell In this case the program names must end with sh The s option indicates that programs are to be linked so that they will run independently of the Shell If no address is specified the programs will be linked at the start of BASIC memory so that they may be LOADed and RUN If an address is specified in either decimal or hex hex numbers must be identified by a preceding symbol the programs will be linked there Object files will be taken from the designated work disk and the libraries will be sought from the designated system disk Programs written in C may access command line arguments Also I O may be redirected to and from disk files much like UNIX the command pr gt gt will direct the standard output to device 4 usually a printer The following examples were adapted from The C Programming Language by Kernighan and Ritchie and are provided to illustrate these features sort n Sorts the standard input and writes the result to the standard output The n option indicates that the input is to be sorted in numerical order The default is alphabetical order actually lexicographic order i find x n string Finds all occurrences of
7. be lined up Format fills by default page 55 fo left footer center footer right footer Set footer bottom of page titles The strings left footer center footer right footer will be written at the bottom of each page left justified centered and right justified respectively All occurrences of the character in the strings will be replaced with the current page number ahe left header center header right header Set header top of page titles in n Set indentation N spaces will be placed at the start of each output line Default n 0 is n Set line spacing N 1 blank lines will be inserted between each line of text Default n l mli n Set margin above and including the header to n Default n 3 m2 n Set margin below header to n Default n 3 m3 n Set margin above the footer to n Default n 3 m4 n Set margin below and including the footer to n Default n 3 ne n Need n lines If there are fewer that n lines remaining on the current page then skip to a new page page 56 nf Stop filling text Lines will be copied from input to output without change except for indentation and line spacing pi n Set page length number of lines per page Default n 66 qm n Set right margin the right most character position to be written to Default n 60 Sp n Write n blank lines cti n Temporary indent The next output line and only that line will be given an indentation of n rathe
8. be loaded and run If a unit number is specified in front of the filename the specified unit will be searched for that filename Edit Mode Function Keys crsr keys 7 fl f2 f3 f4 f5 f6 f7 f8 lt clr home gt a lt shift gt lt clr home gt lt shift gt lt RETURN gt E lt run stop gt lt esc gt Command Mode for the Commodore 128 up down left and right page down page up search down search up cut text lt SHIFT gt lt RUN STOP gt starts use cursor keys to set range paste text f5 deletes f6 inserts go to end of line go to start of line go to bottom of buffer go to top of buffer open a line enter select mode for cut enter command mode for the Commodore 128 In command mode the following commands may be entered dir unit z dos unit command string GEt unit filename PUt unit filename PRint GOto buffername List CHeck QUIT list the specified disk directory send the command string to the specified disk drive unit reads file from disk writes file to disk dumps contents of current buffer to device 4 change current edit buffer lists buffers currently in use ced sh only check syntax exit editor page 13 CLEAR clear current buffer CLEAR buffername clear specified buffer searchstring lt f3 gt set search string and search down searchstring lt f4 gt set search string and search up dog lt f3 gt
9. be truncated even if it won t fit in the specified field If the first digit of the field width is zero the field will be padded with zeros otherwise it will be padded with spaces The maximum field width is 64 characters page 33 An optional period followed by a number indicating the precision for a float or string argument For floats the precision indicates the number of digits to be printed after the decimal point default is six If the precision is explicitly zero no decimal point is printed For strings the precision indicates the maximum number of characters from the string to be printed default is the whole string A letter indicating the type of conversion to be performed The following letters are recognized d an integer argument is printed as a possibly signed decimal number u an integer argument is printed as an unsigned decimal number o an integer argument is printed as an octal number x an integer argument is printed as a hexadecimal number f a float argument is printed S a character pointer argument is assumed to point to a null terminated string which is printed c an integer argument is assumed to be a character and is printed as such For each conversion specifier a corresponding argument of an appropriate type must be provided To output a percent character use A star may be used in place of the field width or precision The value will be taken from an integer argument EXAM
10. called test c and test2 c both would have to have been compiled separately and would have produced two object files called test o and test2 o This would be the time to link in the second file test2 0 However since our test program is a simple one that is not the case and we will now link in the appropriate library functions page 49 Linking Library Functions At the next gt linker prompt remove your work disk from the disk drive unit and replace it with your C Power Library diskette located on the reverse side of your system diskette Link the appropriate function libraries automatically by typing lt gt lt RETURN gt Arrow Up not Cursor Up When the gt Linker program prompt returns to the screen indicate that you are through linking by pressing lt RETURN gt The Linker will now request a filename for the compiled C program Place your work disk in drive 0 and type in test sh lt RETURND gt An sh extension or ending to the filename is necessary because it is required when the compiled C program is to run from within the shell environment Test sh Once the test sh program has been written to the work disk by the linker the program will return to the Shell environment and the prompt will return to the screen When this occurs you may test your newly compiled C language program by typing test lt RETURND If all has gone well Pro Line Software Ltd s corporate name and address will appear on the screen T
11. object code here just for practice Remove the work disk with the test o file on it and place the System disk into the drive Now call the Trim program from the disk by typing after the Shell prompt trim lt RETURN gt When Trim is loaded the program will remind you of the syntax it expects you to use Remove the System disk and replace it with the work disk that contains the test o program Type trim test o lt RETURN gt Trim will proceed to optimize the test o object file and when it is through will show the results of it s efforts on the screen Wait for the trimmed file to be written back to your work disk Now your test o file is ready for linking and the program is back in the shell environment and is displaying the prompt Linking From the prompt in the shell program place the system disk back in the disk drive unit and call the Linker program by typing link lt RETURN gt When the Linker program is loaded the screen will display the Linker s unique prompt sign gt Any time this gt sign appears on the screen you will know that the Linker is ready for your commands Place your work disk that contains the test o file in the disk drive unit Tell the Linker that you want it to link in the object code file named test o by typing test o lt RETURND The Linker will now load test o from the work disk and then once again display the gt Linker prompt If the test c source file had consisted of two files
12. of line f8 go to start of line lt cir home gt go to bottom of buffer lt shift gt lt clr home gt go to top of buffer lt shift gt lt RETURN gt open a line lt shift gt lt run stop gt enter select mode for cut amp paste lt run stop gt enter command mode Command Mode for the Commodore 64 In command mode the following commands may be entered dir disk command string GEt filename PUt filename PRint GOto buffername List list the specified disk directory send the command string to the specified disk drive unit reads file from disk writes file to disk dumps contents of current buffer to device 4 change current edit buffer lists buffers currently in use CHeck ced sh only check syntax QUIT exit editor CLEAR clear current buffer CLEAR buffername clear specified buffer searchstring lt f3 gt set search string and search down searchstring lt f4 gt set search string and search up dog lt f3 gt search for next occurrence of dog dog cat lt f3 gt search for next dog and replace it with cat dog cat lt f3 gt search and replace all dog s with cat s dog lt f3 gt delete next occurrence of dog dog lt f3 gt delete all occurrences of dog lt RETURND return to edit mode page 10 C SHELL COMMAND INTERPRETER for the Commodore 128 bye Exit to BASIC dir unit pattern List the directory of the designated disk to th
13. period on an otherwise blank line 3 0 The Library Although a substantial attempt has been made to make the library provided with the compiler as standard as possible the lack of a standard operating system on the Commodore 64 has required that some compromises be made Before using a function listed in the UNIX or other standard library look up the description of the Spinnaker version in the library section page 4 Interfacing with Machine Language Although C is well suited to a wide range of tasks no high level language can match the speed and compactness of hand written assembly code especially with a micro processor such as the 65xx or 85xx Thus if speed is critical for a particular part of an application or if a program is too large to be written entirely in C it would be desirable to be able to call machine language subroutines from within a C program This can be done with the library function sys whose description can be found in the library section The recommended procedure is to first write those sections of the program which are to be eventually written in assembler as C functions Once the program is debugged the C functions may be replaced one at a time with assembler routines Better Working s Power Assembler may be used The advantage of this approach is that it maximizes portability since the very non portable machine language calls are isolated in a set of functions Also if the computer the program is bein
14. pointed to by ptr into the free memory list Malloc calloc and realloc all return the null pointer 0 if there is not enough free memory to satisfy the request EXAMPLE Run time array allocation define NELEM 100 char malloc int t t int malloc NELEM sizeof int TP eee OT free t done with array _ page 29 NAME open close BASIC style open SYNOPSIS open fileno device secaddr name char name close fileno DESCRIPTION The arguments of open correspond exactly to the file number device number secondary address and file name arguments of the BASIC OPEN command Consult a Commodore 64 manual for the meanings of the arguments Similarly close corresponds to the BASIC CLOSE command Open returns zero if the file can t be opened non zero otherwise As with fopen ferror should be checked after opening a write file The file number argument may be used any place a stream i e a value returned by fopen is used see example File numbers 1 through 4 are reserved for system use If open and fopen are to be used at the same time file numbers passed to open should be limited to the range 5 through 9 EXAMPLE display disk file on screen include lt stdio h gt char cC open 5 8 5 filename s r for c getc 5 EOF putchar c close 5 page 30 NAME opendir readdir rewinddir closedir directory functions SYNOPSIS include lt d
15. the system disk is the Library Disk It contains the Stdlib l1 and Syslib l1 Function libraries This Library Disk should also be backed up immediately and we suggest that you use that work copy of the Library Disk rather than take a chance with the original Instructions for making back up disks are contained in your disk drive manual TABLE OF CONTENTS Compatibility 1 ML Interface 5 Coding Efficiently 7 C SHELL Command Interpreter 8 Commodore 64 8 Commodore 128 11 FUNCTION KEYS Commodore 64 10 Commodore 128 12 13 EDITOR Commodore 64 10 Commodore 128 13 COMPILER 15 LINKER 15 LIBRARY Introduction 16 FUNCTION Index 18 FUNCTION Library 19 TUTORIAL 47 C SHELL UTILITIES 53 RECOMMENDED READING LIST 59 INDEX 60 Compatibility 1 1 1 2 Spinnaker s POWER C compiler is generally quite compatible with those found on other micro computers and mainframes However there are a few potential compatibility problems in all C language compilers which should be kept in mind if you plan to port code from other machines to the C64 or vice versa The main areas of concern are l Standard C features not implemented or not implemented completely 2 Implementation dependent details e g type sizes 3 Non standard library functions These will be discussed in the following sections Features Not Implemented Bit Fields To obtain the effect of bit fields the programmer must use shifts and masks For example to get the value of
16. E AUTHOR Commodore 64 System Guide Commodore 128 System Guide Commodore 64 Programmer s Reference Guide INNER SPACE ANTHOLOGY Karl Hildon THE C PROGRAMMING LANGUAGE Kernighan amp Ritchie C PRIMER PLUS The Waite Group THE C PRIMER Hancock amp Krieger THE C PROGRAMMING TUTOR Wortman amp Sidebottom PROGRAMMING IN C Robert J Traister C PROGRAMMING GUIDELINES Thomas Plum C A REFERENCE MANUAL Tarton Labs THE C PROGRAMMER S HANDBOOK Thom Hogan page 59 PUBLISHER Commodore Commodore SAMS BOOKS Transactor Prentice Hall SAMS BOOKS McGraw Hill Prentice Hall Prentice Hall Prentice Hall Prentice Hall Prentice Hall POWER C INDEX bit fields 1 quit 12 bye command 8 11 register declaration 3 ced command 9 12 remove command 8 11 character constants 4 screen colors 10 11 check command 10 13 search and replace 10 14 clear command 10 14 setu command 11 coding efficiently 7 shell 8 11 color command 11 sign extension 3 command interpreter 8 11 sign fill 3 command mode 10 13 sort command 9 12 commands 9 12 special symbols 14 compatibility 1 string constants 4 compiler 15 system configuration 47 conditional operator 2 trim program 58 copy command 11 tutorial type sizes 47 cp command 11 type sizes 3 cut and paste 14 wfreq command 9 13 dir command 11 zero page usage 6 dos command 11 ed command 9 12 editor 10 13 efficient coding 7 end of file marker 4 exit command 8 11 find command 9 12 find program 53 format program 55 fun
17. OWER C System and Library disks POWER C was designed to be compatible with the Spinnaker Turbo Load and Save cartridge Turbor Load and Save used in conjuction with a Commodore 64 computer equipped with a Commodore 1541 Disk Drive unit speeds all POWER C loading and saving operations by up to 500 Load POWER C by typing load 8 lt RETURN gt then when the READY prompt returns type run lt RETURN gt when the shell program is run the screen will turn grey and a white sign with a flashing cursor next to it will appear at the upper left corner of the screen for Commodore 128 You will need a properly formatted blank diskette to use as a work disk as well as your POWER C 128 System and Library disks page 47 The POWER C 128 System Disk may be auto booted If the POWER C 128 System Disk is in the disk drive unit when the computer is turned on or is reset the Shell program will load and run automatically Otherwise dload shell lt RETURN gt will do the loading job nicely and run lt RETURN gt will RUN it Shell The Shell program creates the operating environment that all the rest of the POWER C compiler package programs work within When the Shell program is active it s unique sign prompt will appear on the screen We will compile trim and link a small source program called test c contained on the System disk All source code programs are identified by a c extension or ending to their names When the
18. PLES print d f 123 3 14 output 123 3 140000 printf 05x 0x2a3 output 002a3 printf abc fxyz 9 2 12 3456 output abcl2 34 xyz page 34 NAME putc putchar fputc putw output a character or integer include lt stdio h gt putc c stream FILE stream putchar c fputc c stream FILE stream putw i stream FILE stream DESCRIPTION Putc and fputc write the character c to the specified stream Putchar writes the character c to the standard output Puts writes the integer i two bytes to the specified stream NAME puts fputs output a string SYNOPSIS include lt stdio h gt puts s char s fputs s stream char s FILE stream DESCRIPTION Puts writes the null terminated string s to the standard output also writes a newline character after the string Fputs writes the null terminated string s to the specified stream does not write an additional newline character page 35 Puts Fputs NAME qsort general purpose sort SYNOPSIS qsort base nel elsize comp char base int comp DESCRIPTION Qsort sorts an array beginning at base containing nel elements each of size elsize Comp points to a function which compares elements The function must take two pointers to elements and return an integer less than equal to or greater than zero as the first element is less than equal to or greater than the second EXAMPLE Sort array o
19. Z Match lines starting with a possibly empty string of lower case letters and ending with a non empty string of upper case letters _a zA Z _a zA Z0 9 0 9 0 9 Match lines containing an assignment of an integer constant to a C identifier Note that this pattern would have to be enclosed in double quotes since it contains spaces page 54 Name format text formatter Synopsis format filename filename Description Format reads text from the standard input if no arguments are given otherwise it reads from the specified files Output is written to standard output Input may consist of ordinary text which is filled and justified by default and formatting commands Formatting commands consist of a period in the first character position of a line a two character code and for most commands an optional argument The commands recognized by the formatter are ebp n Begin page numbered n This forces the start of a new page with page number n The default for n is the current page number plus 1 br Cause a break This forces any accumulated text not yet written to be written immediately Several commands implicitly cause a break before they perform their function These are bp ce fi ne nf sp and ti ce n Center the next n lines Default n 1 fi Fill text Text will be filled output lines will contain as many words as possible and right justified right margins will
20. ables are used frequently they should be declared before those used less frequently page 3 2 5 2 6 2 7 2 8 Character and String Constants Multi character constants are not supported If more than one character appears in a character constant only the first is taken String constants may not contain more than 255 characters Header Files The pre processor lines include lt filename gt and include filename are synonymous The header file filename must be on the same disk as the source file containing the pre processor line NOTE If the file is one of the standard header files such as stdio h or math h it must be copied from the system disk to your work disk Program Size Due to the limited memory available in the C 64 the compiler may not be able to handle some very large source files It is unlikely that the Power C 128 compiler will run into insufficient memory problems and not be able to handle the large source files If an overflow message is printed when you are compiling don t despair split the big source file into two or more smaller source files and compile them separately They will join up again when you link them If the linker gives an overflow message you have two possible courses of action use more efficient coding techniques or rewrite some of the program in assembler see the section on interfacing C with assembler EOF Marker End Of File may be signaled from the keyboard with a
21. and comma operators behave this way in subscripts and constant expressions For example the expression afi gt j2 i j will generate a syntax error while the expression ali gt j i jl will be accepted page 2 2 1 2 2 2 3 2 4 Implementation Details Type Sizes The following table lists the size in bytes of all data types supported by the compiler U pis N e Type char short int long unsigned float double pointer dO O1 OTD NN Ne Note that short int and long are synonyms as are float and double Integers and pointers are stored low byte first high byte last Float quantities are stored in the same format as BASIC variables Identifiers All identifiers including external identifiers are significant to eight characters except for goto labels which are significant to seven characters Identifiers may contain up to 255 characters Sign Extension and Sign Fill The compiler does not sign extend character quantities When characters are converted to integers the high byte is simply set to zero Similarly integers are not sign filled when shifted right Vacated bits are set to zero even if the quantity being shifted is negative Register Declarations All register declarations are ignored However the first 32 bytes of integers characters and pointers declared in a function are placed in the zero page while the remainder are put in a stack in main memory Thus if certain vari
22. be relocated when calling machine language subroutines from C and restored when returning In addition the buffer 033c 03ff is used by the system and should not be disturbed Coding Efficiently Due to the way certain features have been implemented in the compiler and the nature of the 65xx 85xx instruction set there are a few non obvious ways of improving the efficiency of some programs written with POWER C Declare variables unsigned rather than int if they never contain negative values For example variables which are used only as array indices should always be declared unsigned If a function contains many variables declare those used most frequently first page 7 C SHELL COMMAND INTERPRETER The first program on the System Disk and the first one you should load and run is the Shell mini command interpreter The Shell is a program that supports command line arguments and I O redirection along with the compiler and other programs designed to work under it Load and run the program shell and you will soon see a dollar sign prompt on the screen waiting for one of the commands listed below The Shell lets you define a work disk and a system disk The defaults for both are device 8 and drive 0 but they may be changed as described below if you are lucky enough to have two disk drives There are a number of built in commands which are also listed here Items in square brackets are optional Arguments may optionally be enclosed
23. ction index 18 function keys 10 12 get command 10 13 goto 10 13 header files 4 identifiers 3 interfacing with ML 5 library 4 library intro 16 link command 9 12 linker 15 liner prompt 15 linking functions 49 list command 10 13 load command 8 11 machine language 5 move command 8 11 operators 2 optimizing 49 pointer init 1 print command 8 11 print program 33 55 program size 4 put command 10 13 page 60 IN D PWC
24. e of sys is to access kernal routines not otherwise supported by the standard library The bank in which the machine code resides must be specified by a number from 0 to 15 SEE Basic BANK command EXAMPLE char s x y s this string will be written to the screen while s sys 15 Oxffd2 s amp x amp y ffd2 is the kernal routine for printing a character page 46 POWER C TUTORIAL System Configuration for Commodore 64 POWER C has been designed to work with a Commodore 64 computer equipped with up to four Commodore 1571 or Commodore 1541 disk drive units A Commodore 1525 MPS 801 MPS 803 or equivalent printer is optional Please be aware that some printers do not have the special C language characters in their built in fonts and so cannot print them POWER C will output 40 column video to a Commodore 1701 or 1702 color monitor We cannot guarantee that any other system configuration will function properly for Commodore 128 POWER C 128 has been designed to work with a Commodore 128 computer equipped with up to four Commodore 1571 or Commodore 1541 disk drive units A Commodore 1525 MPS 801 MPS 803 or equivalent printer is optional POWER C 128 will output either 128 40 column or 128 80 column video We cannot guarantee that any other system configuration will function properly Startup for Commodore 64 You will need a properly formatted blank diskette to use as a work disk as well as your P
25. e standard output screen setu unit device drive Redefines any of the 4 available disk drive units e g setu 1 9 0 would define Unit 1 as device 9 drive 0 rm unit pattern Remove scratch a file on the designated disk drive unit mv unit Joldfilename newfilename Move rename oldfilename to newfilename on the designated disk drive unit pr unit filename List the contents of a file on the work disk to the standard output screen pr gt gt unit filename Same as above but redirects the output to device 4 usually the printer dos unit command string Send a command string to the designated disk drive unit ie dos 0 header id would format the disk in the designated disk unit drive 0 load command Load but don t run the specified command from the designated disk unit cp sourceunit pattern destinationunit pattern Copies all files matching the pattern from the source unit to the destination unit rdon Enables RAMDISK rdoff Disables RAMDISK col foreground background status line border e g col 1 0 5 7 would set the foreground color to white background to black status line in editor only to green and the border in 40 column mode only to yellow page 11 Function Keys for the Commodore 128 The Function Keys have been defined as follows Fl dir F5 ec F2 setu F6 link F3 ed F7 pr F4 ced F8 amp cp NOTE You may change between 40 and 80 colu
26. ecause C is not tied to any one particular manufacturer s hardware or Disk Operating System Thus it is rapidly becoming a major program transportability factor between the multitude of different CPU s and operating systems from mainframes to minis to micros C was originated and placed in the public domain by Dennis M Ritchie of Bell Labs The C language has been described as a simple and elegant programming language with an absence of restrictions and a generality that makes it far more effective and convenient than supposedly more powerful programming languages The UNIX operating system was written in C Most current terminal programs and many of the new word processors have been written in the C language What an incredible luxury for a programmer to be able to compile his C source for each of several different CPU s instead of rewriting new source code for each C is easy to learn as it has only about a dozen commands and depends on function libraries to gain speed and efficiency GETTING STARTED Your POWER C System Disk contains the C Shell Editors Compiler Translator Linker Stdio library Math library and five sample C source code listings test c format c and format2 c print c sort c find c and wfreq c We strongly advise that a back up system disk be made from the original system disk and used instead of the original which should then be stored safely away until needed to create another back up The reverse side of
27. ess unsigned bank address peek returns unsigned bank address DESCRIPTION peek returns the contents of the memory location in bank bank at address address page 32 NAME for Commodore 128 poke BASIC style poke command SYNOPSIS poke bank address value unsigned bank address value DESCRIPTION poke puts the byte value into the memory location specified by bank and address NAME printf fprintf sprintf formatted output SYNOPSIS include lt stdio h gt printf control arg char control fprintf stream control arg FILE stream char control sprintf s control arg char s control DESCRIPTION These functions output optional lists of arguments according to a format specified in the null terminated control string Printf sends output to the standard output Fprintf sends output to the specified stream Sprintf places output in the string s Sprintf also places a null character in s after the last output character The control string may contain ordinary characters which are output and conversion specifiers which specify how an argument is to be formatted Each conversion specifier begins with a percent character and is followed by An optional dash which indicates left adjustment of the argument in the output field Right adjustment is the default An optional number indicating the minimum field width A converted argument will not
28. f floats define NELEM 100 float t NELEM int fcomp qsort t NELEM sizeof float fcomp AE aas Y fcomp pl p2 float pl p2 if pl lt p2 return 1 else if pl p2 return 0 else return 1 page 36 NAME random srandom random number generator SYNOPSIS random srandom seed DESCRIPTION Random returns a pseudo random integer Srandom sets the state of the random number generator If srandom is called twice with the same seed the same sequence of random integers will be generated page 37 NAME scanf fscanf sscanf formatted input SYNOPSIS include lt stdio h gt scanf control arg char control fscanf stream control arg FILE stream char control sscanf s control arg char s control DESCRIPTION These functions read sequences of characters perform conversions specified by the control string on them and store the converted values indirectly through pointer arguments Scanf reads from the standard input fscanf reads from the specified stream and sscanf reads from the string s The control string may contain blanks and newlines which may match optional blanks and newlines from the input other ordinary characters which must match corresponding characters from the input and conversion specifiers Each conversion specifier begins with a percent character and is followed by An optional star which suppres
29. g ported to has a larger memory than the C 64 machine language routines may be unnecessary in which case you can use the original C functions The following small example illustrates the procedure The code which is to be written in assembler is to add three small positive integers The code is first written as a C function add3 which is shown below along with a driver program include lt stdio h gt main int a b c while printf enter three numbers scanf d d d amp a amp b amp c EOF printf sum d add3 a b c add3 argl arg2 arg3 return argl arg2 arg3 page 5 The rewritten add3 with the associated machine language subroutine located at c000 hex is shown below add3 args c000 stx 4b float args sty 4c cle char a xX y Idy 0 Ida 4b y load arg 1 x int amp args Idy 2 y int amp args gt gt 8 adc 4b y add arg 2 sys 0xc000 amp a amp x amp y Idy 4 return a adc 4b y add arg 3 rts Note that only one argument is declared and that it is given type float This is to ensure that the arguments remain in consecutive memory locations and in the correct order Note also that the x and y registers are loaded with the low byte and high byte of the address of the argument list respectively and that the result is returned in the accumulator If the machine code is placed in higher memory than the C code the library function highmem s
30. hat the function atof takes one argument of type pointer to char and returns a float abs i This means abs takes one argument of type int and returns an int If a function returns a type other than int it should be declared in the file which calls the function For example before any calls to malloc the following declaration should appear char malloc Header files which are useful when using certain functions are also listed in this section If the line include lt stdio h gt is listed for example the same line should be put into the source file which calls the function s described on that page page 16 DESCRIPTION This section describes what the functions do what the arguments are and what the functions return if anything If a function checks the arguments for validity or does any other kind of error checking it will be described here Otherwise it should be assumed that no error checking is done EXAMPLES For some of the more complicated functions examples illustrating their use are listed In the examples the symbols mean the preceding and following code may be separated by some arbitrary amount of code page 17 FUNCTION INDEX For Page abort abs acos asin atan atan2 atof atoi bemp bcopy bzero cabs calloc ceil close closedir cos cosh exit exp fabs fclose feof ferror ffs fgetc fgets floor fopen fprintf fputc fputs fread free freopen frexp fscanf fwrite
31. he test program could have been compiled to run directly from BASIC if back at the step where you called the Link program you had typed in link s lt RETURN gt informing the linker that it should not compile the test program to run under the shell but from the start of BASIC address The compilation procedure is exactly the same up until the end of the trim operation You may wish to re link the test o files to run from BASIC in which case use a slightly different name for the compiled program like testl to distinguish it from the test sh program you have already compiled To run this testi program from BASIC reset the computer back to BASIC from the Shell environment by typing bye lt RETURND gt then when the computer resets type lt SHIFT gt lt LOGO gt to put the C 64 in upper lower case mode then type load test1 8 lt RETURN gt When loading is complete type lt RUN gt lt RETURN gt and the results should be the same as when you ran it from the shell environment page 50 for the Commodore 128 then when the computer resets type lt SHIFT gt lt LOGO gt to put the C128 in upper lower case mode then type dload test lt RETURND gt When loading is complete type lt RUN gt and the results shsould be the same as when you ran it from the shell enviroment Ramdisk for the Commodore 128 C Power 128 gives you the option of using the Commodore 128 s extra memory as either an extra large wo
32. hould be called to limit the memory which the C code can use In the above example the statement highmem 0xc000 should be included in the main function before the first call to add3 If the machine code is to placed below the C code remember to enter an appropriate starting address when linking the C program Zero Page Usage for Commodore 64 The zero page locations 20 33 43 74 and 253 254 decimal are reserved for permanent system use and should not be disturbed The locations 34 42 75 96 and 251 252 are used as temporary storage and may also be used as such in your machine language routines The remainder of the zero page may be used as you wish but caution should be observed when using locations used by kernal routine or BASIC floating point routines In addition the tape buffer 033c 03fb is used by the system and should not be disturbed page 6 Memory Usage for Commodore 128 Bank 0 0600 06ff System storage 0800 09ff Ram disk header information 1300 13ff Relocated zero page used by all programs including compiled programs except the shell 1400 37ff Shell program 3800 3fff Character set 4000 feff Ram disk or tables for linker and compiler or user defined Bank 1 0400 UP Highmem 1 All programs including compiled programs except the shell reside here NOTE 1 highmem defaults to ff00 and may be changed with the highmem library function NOTE 2 Zero page should
33. in double quotes which is necessary if they contain spaces for the Commodore 64 bye Exit to BASIC 1 pattern List the directory of the work disk to the standard output screen Is pattern List the directory of the system disk to the standard output screen rm filename Remove scratch a file on the work disk mv filel file2 Move rename filel to file2 on the work disk pr filename List the contents of a file on the work disk to the standard output screen pr gt gt filename Same as above but redirects the output to device 4 usually the printer disk command string Send a command string to the work disk device ie disk n0 headername id would format the disk in work disk device load command Load but don t run the specified command from the work disk or the system disk wherever it is work device drive With no arguments entered displays the current work disk device and drive numbers It may also be used to change the device and drive numbers page 8 Commands for the Commodore 64 There are a number of commands provided which are loaded from disk ed filename ced filename Load and run the editor ed or syntax checking editor ced If a file is specified it is loaded into the main editing buffer cc p filename c Compile the C source code in the specified filename If the p option is specified the compiler will assume that you are using two disk drive units
34. ir h gt opendir unit struct direct readdir rewinddir closedir DESCRIPTION Opendir opens a disk directory for reading The unit from which the directory is to be read may be specified If the directory can t be opened NULL is returned NOTE The directory functions do not apply to the RAMDISK Readdir reads the next directory entry and returns a pointer to it If there are no more entries NULL is returned See the header file dir h and the VIC 1541 User s Manual page 56 for the format of a directory entry Rewinddir causes readdir to read the first entry upon the next call Closedir closes the directory for EXAMPLE Display contents of disk directory include lt dir h gt include lt stdio h gt struct direct dp opendir 0 int unit for dp readdir dp NULL dp readdir puts dp gt name closedir page 31 NAME for Commodore 128 open2 BASIC style open to unit number SYNOPSIS open2 name filename unit channel char name int filenum char unit int channel DESCRIPTION open2 is the same as open except that the disk drive is specified by a unit number rather than a device number If filename is not empty then the unit number is taken from there otherwise it is taken from unit EXAMPLE open2 3 filename 5 don t care 5 open2 15 O 15 NAME for Commodore 128 peek BASIC style peek command SYNOPSIS peek bank addr
35. k in that something now Once everything is linked you are asked for the name of the program to be saved on disk If you did not specify a starting address then this program may simply be LOADed and RUN Otherwise you must LOAD with the 1 option and SYS to the starting address You may exit the linker at any time by entering x lt RETURN gt at any linker prompt gt NOTE 1 The linker will only accept files whose names end with o obj or vil NOTE 2 Typically the linking commands would appear thusly gt filenamel o link first object file gt filename2 o link second object file if you have one gt link libraries CUP ARROW not lt CURSOR UP gt lt RETURN gt all finished page 15 LIBRARY INTRODUCTION The following pages describe the functions available in the library provided with the compiler Most of the functions are in the library files syslib 1 and stdlib l the remainder are in the file math l See the section on the linker for information on how to link these libraries into your C program Each page is divided into three or four sections NAME The names of the functions described on the page are listed here with a very brief description SYNOPSIS The purpose of this section is to show the number order and types of arguments each function takes as well as the type the function returns If no types are specified int is to be assumed For example float atof fptr char fptr Means t
36. mn displays by putting the lt DISPLAY gt in the opposite position then press the lt RUN STOP gt and lt RESTORE gt keys at the same time The monitor will of course also have to be switched Commands for the Commodore 128 There are a number of commands provided which are loaded from disk ed unit filename ced unit filename Run the editor ed or syntax checker ced from the designated unit If a file is specified it is loaded into the main editing buffer ec p unit filename c Compile the C source code in the specified filename on the designated unit If the p option is specified the compiler will assume that both the source object and compiler disks are present and will not tell you to change disks all the time link s unit address Run the linker If no arguments are given programs are linked in such a way that they will run under the Shell In this case the program names must end with sh The s option indicates that programs are to be linked so that they will run independantly of the Shell If no address is specified the programs will be linked at the start of BASIC memory with a boot program so that they may be LOADed and RUN If an address is specified in either decimal or hex hex numbers must be identified by a preceding symbol the programs will be linked there Programs written in C may access command line arguments Also I O may be redirected to and from disk files much like UNIX gt gt
37. n Fclose closes the specified file EXAMPLES include lt stdio h gt FILE f open sequential file for reading f fopen abc r open and replace program file f fopen 0 xyz p w assign standard output to a disk file f freopen outfile w stdout page 23 NAME fread fwrite array input output SYNOPSIS include lt stdio h gt fread ptr elsize nelem stream char ptr FILE stream fwrite ptr elsize nelem stream char ptr FILE stream DESCRIPTION Fread fwrite reads writes an array containing nelem elements each of size elsize bytes beginning at ptr from to the specified stream Fread returns zero upon end of file EXAMPLE include lt stdio h gt define N 500 float x N FILE f f fopen datafile r fread x sizeof float N f page 24 NAME frexp Idexp split float into mantissa and exponent SYNOPSIS float frexp value ptr float value int ptr float Idexp value exp float value DESCRIPTION Frexp splits value into a mantissa m of magnitude less than 1 which is returned and an exponent exp which is stored indirectly through ptr such that value m 2 exp Ldexp returns value 2 exp NAME getc getchar fgetc getw input character or integer SYNOPSIS include lt stdio h gt int getc stream FILE stream int getchar int fgetc stream FILE stream int getw stream FILE stream DESCRIPTION Getc and fge
38. n BASIC Complete language components such gs shell full screen syntax checking editer compder linker etc Complete library of over 95 functions Complete Gbrary of C uflities including such utilities os sort find and a powerful text formatter A tutorial te gef you started Full support of floating poini Conformation to Kemighan and Ritchie shendards l Baiar Warkisg h a woderigrk of Spinnaker Software Cep 1996 Spintgker Safwora Cep Dne Keadol Squere Combridge MA 07139 All right med Spitryher no gared todemark af Spinnaker Software Corp Un copy protected disks s back up c pies ore hossle fres nau Anl Two complete develooment enviranmernts ome for the C 44 ond one for the C 12 af i my TOLSE gresa OE Ce Hide oe BX PWC Copyright 1986 by Spinnaker Software Corporation All rights reserved The distribution and sale of this product are intended for the use of the original purchaser only and for use only on the computer system specified Lawful users of this program are hereby licensed only to read the program from its medium into memory of a computer for the purpose of executing this program Copying duplicating selling or otherwise distributing this product is hereby expressly forbidden Commodore 64 and 128 are trademarks of Commodore Business Machines Inc FOREWORD The use of the C programming language is probably one of the more important developments in the micro computer field b
39. om the standard input The options are X Write the line number of each matched line f N Only write lines which don t match the pattern Write the file name before each matched line Patterns may consist of ordinary characters which match corresponding characters in the input and special characters or meta characters which match special patterns These characters are Match any character Match zero or more occurrences of the previous element of the pattern Match the start of a line Match the end of a line class Match any character belonging to the specified character class A character class is simply a list of characters For example aeiou matches any lower case vowel Character classes may be abbreviated if they contain sequences of consecutive letters or digits For example A Z matches any upper case letter and aeiou0 9 matches any vowel or digit class Match any character NOT belonging to the character class Preceding a meta character with an at symbol will cause it to be treated as an ordinary character Thus matches a single question mark and matches a single at symbol page 53 Examples abc Match lines containing the string abc tabc Match lines starting with the string abc X y Match lines containing an x followed by any character followed by a y x y Match lines containing and x and ending with a y la z A Z A
40. ould always end with c When finished the compiler will leave an object file on disk with the same name as the source except the extension c will be replaced with o LINKER link sh From the Shell program prompt type in link s address lt RETURN gt to load and run the linker If no arguments are given programs are automatically linked in such a way that they will run under the control of the Shell program In this case all program names must end in sh The s option indicates that you want the programs to run independently of the Shell program If no address is specified the programs will be linked beginning at the start of basic address so that they may be LOADed and RUN If an address is specified in either hex or decimal identify hex numbers with a preceding symbol the programs will be linked from that address on Object files will be taken from the work disk and the library files will be looked for on the system disk You will then be greeted by a gt linker prompt Type in the names of the object files i e o files that you wish to link together When you have finished this insert the library disk and press lt f gt lt RETURN gt This will automatically link in the necessary functions from the standard library and system library When the above has been completed press lt RETURND If you get an unresolved external reference message then you forgot to link in something No problem just lin
41. r than the value set by in Default n 0 Numeric arguments may be specified in two ways as absolute unsigned integers or as signed integers Absolute arguments are assigned to parameters in the obvious way ls 2 sets the line spacing to 2 Signed arguments indicate a change in the current value of the parameter being set the value of the argument is added to or subtracted from the current value For example the commands pl 66 pl 10 will set the page length to 56 and n 10 ein 5 will cause a temporary indent of 15 Blank lines and lines starting with spaces occurring in the input are special cases Blank lines cause a break and a number of blank lines equal to the current line spacing to be written Lines starting with spaces cause a break and a temporary indent of n where n is the number of spaces before the first non space character on the line page 57 Name print page files Synopsis print filename filename Description Print writes the named files or the standard input if none are specified to the standard output with margins at the top and bottom of each page and a header at the top of each page Name trim code optimizer Synopsis trim filename o Description Trim optimizes the o or obj files produced by the compiler prior to LINKing You can expect to reduce compiled file sizes in the order of 3 to 8 percent page 58 RECOMMENDED READING LIST REFERENC
42. rkspace or as a pair of small software ramdisks When C Power 128 is freshly loaded the internal ramdisks are not enabled From the Shell environment use the commands rdon to enable the ramdisks and rdoff to shut them off There are two built in internal software ramdisks available for use They are set up as device 7 drive 0 and device 7 drive 1 Their default unit numbers are Unit 2 and Unit 3 Each ramdisk has 191 blocks free when first enabled and will retain any files saved to them until the computer is powered down Obviously you must copy any important files saved on the ramdisks to a regular floppy diskette before you turn off your computer Why bother with ramdisks then Because they are lightning fast compared to regular disk drives and if you are concerned with the length of time it takes to load the compiler and translator programs try copying them into ramdisk unit 2 and accessing them from there You can use a ramdisk unit as a work disk if you wish and enjoy the the freedom from disk swapping that a second disk drive brings Just don t forget to copy your work down to a floppy before you shut down In an external dual drive system C Power 128 assumes that unit 0 will contain the work disk and unit 1 will contain the system disk page 51 Example for the Commodore 128 From the Shell environment try this Insert the System Disk in your regular disk drive rdon turn on ramdisks cp O test c 2 copy tes
43. search for next occurrence of dog dog cat lt f3 gt search for next dog and replace it with cat dog cat lt f3 gt search and replace all dog s with cat s needs lt f2 gt or lt f3 gt to start search up or down dog lt f3 gt delete next occurrence of dog dog lt f3 gt delete all occurences of dog lt RETURND return to edit mode Special Symbols used in C The special C characters used in creating C language source code may be obtained as follows curly brackets and lt shift gt and lt shift gt back slash lt english pound sign gt tilde lt logo gt p underscore _ lt logo gt vertical bar lt logo gt NOTE 1 Use the lt logo gt key in the above examples the same as you would a shift key hold it down while pressing the next character NOTE 2 To CUT and PASTE in EDIT mode first enter SELECT mode by pressing the lt SHIFT gt lt RUN STOP gt key Set desired range with the lt CURSOR gt up and down keys and then the lt RETURN gt key to accept the chosen highlighted range Now press lt F5 gt to CUT delete or lt F6 gt to PASTE insert page 14 COMPILER cc sh From the Shell program prompt type cc p filename c lt RETURND and the compiler will be loaded from the specified unit and run with the specified filename c If you type in the p prior to the filename c the compiler will assume you are using two disk drives The filename sh
44. ses assignment of the converted value An optional number which specifies the maximum field width Characters are read up to the first unrecognized character for the type of conversion being performed or until the number of characters read equals the field width whichever comes first If no field width is specified characters are read up to the first unrecognized character MORE page 38 scanf continued A letter indicating the type of conversion to be performed on the field The following letters are recognized d the field is expected to contain a possibly signed decimal number which is converted into an integer x the field is expected to contain a hexadecimal number which is converted into an integer o the field is expected to contain an octal number which is converted into an integer f the field is expected to contain a possibly signed decimal number with an optional decimal point and exponent which is converted into a float s no conversion is performed the field is copied into a string argument with a null character appended c the field contains a single character which is copied into a character argument For each conversion specifier except for those which suppress assignment there must be a corresponding argument which is a pointer to an appropriate type For example d conversion requires that there be a pointer to an int or an unsigned To match a percent character from the input use These f
45. t c from unit 0 to unit 2 cp O stdio h 2 copy stdio h from unit 0 to unit 2 cc 2 test c compile test c found on unit 2 trim 2 test o trim test o found on unit 2 link load linker gt 2 test o link test o file Insert Library Disk gt lt p link libraries gt lt RETURND to signal finished with linker Program file name 2 test write test sh to unit 2 dir 2 get a directory of unit 2 test run test program Insert work disk in unit 0 cp 2 test sh 0 copy test sh from unit 2 to unit 0 rm 2 erase all files from unit 2 Try copying both the test c and stdio h files from your system disk onto your work disk and the three files cc sh compiler and translator from your system disk to ramdisk unit 2 Then insert the work disk in the regular drive unit 0 Next compile using the n command parameter to indicate you are using two drives cc n test c dir Compilation will have taken place without any disk swapping required and will have resulted in the object file test o being written to the work disk in unit 0 ready for linking page 52 C SHELL UTILITIES Adapted from SOFTWARE TOOLS by K amp R Name find Synopsis pattern matcher find x n f pattern filename filename Description Find searches the input and writes all lines matching the pattern to the standard output Input is taken from the named files if any otherwise it is taken fr
46. t i float pi atof s 123 i atoi s s 3 14159 pi atof s page 19 NAME bemp bcopy bzero ffs bit and byte string functions SYNOPSIS bemp pl p2 len char pl p2 beopy pl p2 len char pl p2 bzero p len char p ffs i DESCRIPTION Bemp compares len bytes of the strings pl and p2 and returns zero if they are same non zero otherwise Bcopy copies len bytes from string pl to string p2 Bzero fills string p with len zeros Ffs returns the position of the first set bit in its argument Bits are numbered starting at one If the argument is zero ffs returns 1 NAME exit abort terminate execution SYNOPSIS exit abort DESCRIPTION Exit and abort end program execution All files opened by fopen are closed page 20 NAME exp log logl10 pow sqrt assorted math functions SYNOPSIS include lt math h gt float float float float float float float float float float exp x X log x X log10 x X pow x y X y sqrt x X DESCRIPTION Exp returns e x Log returns the natural logarithm of x Logi0 returns the base 10 logarithm of x Pow returns x y Sqrt returns the square root of x page 21 NAME ferror feof check for error or end of file SYNOPSIS include lt stdio h gt ferror feof stream FILE stream DESCRIPTION Ferror returns non zero if an error occurred during the last disk opera
47. tc read a character from the specified stream Getchar reads a character from the standard input Getw reads an integer two bytes from the specified stream All of these functions return EOF upon end of file However since EOF is a valid integer feof should be used to check for end of file after getw page 25 NAME gets fgets input a string SYNOPSIS include lt stdio h gt char gets s char s char fgets s n stream char s FILE stream DESCRIPTION Gets inputs a string from the standard input It reads characters into s until a newline character is encountered The newline is replaced with a zero Fgets inputs a string from the specified stream It reads n l characters or until a newline is encountered whichever comes first The newline is not replaced but a zero is placed after the last character read Both functions return s upon normal completion or NULL upon end of file page 26 NAME highmem memory configuration SYNOPSIS highmem address unsigned address DESCRIPTION Highmem sets the highest address that a C program can use The run time stack will not go past this address and the memory allocation functions malloc calloc realloc will not allocate memory higher than this address The value of the argument must be one greater than the desired address If highmem is not called address defaults to O0xd000 which means the highest address which can be used is Oxcfff EXAMPLE
48. tenate the strings sl and s2 and leave the result in sl Strncat copies at most n characters from s2 Both functions return sl MORE page 44 strcat continued Stremp and strncmp compare the strings sl and s2 and return an integer less than equal to or greater than zero as sl is lexically less than equal to or greater than s2 Strncmp compares at most n characters Strepy and strncpy copy s2 into sl Strncpy copies at most n characters Both functions return sl Strlen returns the number of non zero characters in the string s Index rindex returns a pointer to the leftmost rightmost occurence of the character c in the string s If the character is not in the string a null pointer 0 is returned page 45 NAME sys call a machine language subroutine SYNOPSIS sys bank address aptr xptr yptr int bank unsigned address char aptr xptr yptr DESCRIPTION Sys loads the accumulator x and y registers of the 6510 processor with the values pointed to by a x and y respectively then jumps to the subroutine located at the specified address Upon completion of the subroutine the possibly new values contained in the registers are stored indirectly through the pointer arguments Sys returns zero if the carry flag is clear after the subroutine call otherwise it returns one This function allows the programmer to combine assembler and C code in one program without having to use a special assembler Another us
49. the specified string in the standard input If the x option is specified only lines NOT containing the string are output If the n option is specified output lines will be numbered wfreq Counts the number of occurrences of each word in the standard input A word is defined as a string of characters beginning with a letter and followed by up to 19 letters and digits As stated above programs that work with the Shell mini command interpreter must have file names ending with sh These programs may be invoked by merely typing the name without the sh part along with any arguments and I O redirection specifiers page 9 Once a program is loaded it may be run any number of times without re loading using the built in run command by typing the name without the sh extension and any arguments and or redirection specifiers EDITOR ed sh for the Commodore 64 From the Shell program prompt type in ed filename lt RETURN gt or if you want the syntax checking editor ced filename lt RETURN gt and the chosen editor will be loaded and run If a unit number is specified in front of the filename the specified unit will be searched for that filename Edit Mode Function Keys for the Commodore 64 crsr keys up down left and right fl f2 page down page up f3 f4 search down search up f5 cut text lt SHIFT gt lt RUN STOP gt starts use cursor keys to set range f6 paste text f5 deletes f6 inserts f7 go to end
50. the third through sixth bits of an int variable y one might use the code x y gt gt 2 amp Oxf To assign a quantity to the same field one might use y y amp 0x3c x lt lt 2 where is the bitwise not operator This is admittedly awkward but in practice bit fields are not frequently used so their absence should not present a great problem Pointer Initialization Static pointer variables may not be initialized except for character pointers initialized with strings For example the declaration static char s this is a string is allowed while static int x static int y amp x is not allowed Static variables include variables explicitly declared static and variables declared outside of a function but given no explicit storage class declaration Auto variable initialization is fully supported page 1 1 3 1 4 Conditional Operator Type Conversions The second and third operands of the conditional operator are not brought to a common type if they are different If the types are different the programmer must make the conversion explicit For example the code int i float f x x a b f i may generate incorrect machine code while the statement x a b f float i will generate correct machine code Operators Certain operators under certain conditions will not work unless the expressions containing them are parenthesized Namely the logical or conditional assignment
51. tion zero otherwise Feof returns non zero if the specified stream has reached end of file zero otherwise NAME floor ceil modf get integer part of float SYNOPSIS include lt math h gt float floor x float x float ceil x float x float modf x ptr float x ptr DESCRIPTION Floor returns the greatest integer not greater than x Ceil returns the least integer not less than x Modf returns the positive fractional part of x and stores the integer part indirectly through ptr page 22 NAME fopen freopen fclose open disk file for I O SYNOPSIS include lt stdio h gt FILE fopen filename mode char filename mode FILE freopen filename mode stream char filename mode FILE stream fclose stream FILE stream DESCRIPTION Fopen opens a disk file for reading or writing The string filename contains the name of the file and the first character of the string mode specifies read or write r or w The default file type is sequential but program file types may be selected Fopen returns a file number hereafter referred to as a stream which may be used in later I O or it returns zero if the file cannot be opened Freopen opens a file much the same as fopen does The file stream is first closed then if the open is successful the old stream is assigned to the new file This is useful to assign the constant streams stdin and stdout to disk files Ferror should be checked after every fope
52. unctions return EOF upon end of file otherwise they returned the number of conversions successfully performed This number may be less than the number of conversion specifiers if for example characters in the control string do not match corresponding characters from the input To input strings with embedded spaces use gets or fgets MORE page 39 scanf continued EXAMPLES gi a af include lt stdio h gt int i float f char s 50 c scanf d f amp i amp f input 123 456 result i 123 f 456 0 scanf 3d 5f amp i amp f input 436504 3683 result i 436 f 504 3 scanf lls Spain c s amp c input The rain in Spain falls mainly result s The rain in c f page 40 NAME setjmp longjmp long range goto SYNOPSIS include lt setjmp h gt setjmp env jmp buf env longjmp env val jmp buf env DESCRIPTION Setjmp stores its stack environment in env and returns zero Longjmp restores the stack environment saved by setjmp and returns in such a way that it appears that the original call to setjmp has returned with the value val The calls to setjmp and longjmp may be in different functions but the function containing the setjmp call must not have returned before the call to longjmp EXAMPLE include lt setjmp h gt int errno error jmp buf env errno setjmp env if errno 0 printf error d errno e
53. xit ue ag if error longjmp env 1 page 41 NAME sin cos tan asin acos atan atan2 trig functions SYNOPSIS include lt math h gt float sin x float x float cos x float x float tan x float x float asin x float x float acos x float x float atan x float x float atan2 x y float x y DESCRIPTION Sin cos and tan return the sine cosine and tangent of x respectively X is measured in radians Asin acos and atan return the arcsine arccos and arctangent of x respectively Atan2 returns the arctangent of x y page 42 NAME sinh cosh tanh hyperbolic functions SYNOPSIS include lt math h gt float sinh x float x float cosh x float x float tanh x float x DESCRIPTION Sinh cosh and tanh return the hyperbolic sine cosine and tangent of x respectively page 43 NAME strcat strncat strcmp strnemp strcpy strncpy strlen index rindex string functions SYNOPSIS include lt strings h gt char strcat sl s2 char sl s2 char strncat s2 s2 n char sl s2 stremp sl s2 char sl s2 strncmp sl s2 n char sl s2 char strcpy sl s2 char sl s2 char strncpy sl s2 n char sl s2 strlen s char s char index s c char s C char rindex s c char s C DESCRIPTION All of the following functions operate on character strings terminated with zero Streat and strncat conca
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