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GRAFIN2 USER`S MANUAL

1. Get current iteration counter value of inner loop to stack Get iteration counter value of second outer joop to stack Get iteration counter value of third outer loop to stack Rotate top three stack entries so that ni beconies TOS Copy n2 to TOS Rotate top three stack entries so that n2 becomes TCS Swap n1 and n2 October 1984 GRAFIN2 User s Manual Metheus FORTH Table C 9 System Words Name Function tick mark In interpret mode move dictionary ad dress of next token to TOS comma Put 16 bit value into next two dictionary Pon bytes ABORT Warm start BINARY Set input radix to binary DECIMAL Set input radix to decimal DO Output a signed doubile precision value to terminai EXECUTE Jumps to address at TOS FORGET Forget user definitions after this one inclusive HERE Push address of next free dictionary entry to TOS HEX Set input radix to hexadecimal Table C 10 System Variables Name Function BASE Current input output radix DP Current dictionary pointer October 1984 Ca Methcus FORTH Deletions GRAFIN2 User s Manuali These words are not used by GRAFIN2 and are unsupported They may or may not work with Metheus FORTH Refer to a FORTH reference book for their explanation lt BUILDS CODE CREATE lt R CA END ENTRY COMPILER CONTEXT CORE C 10 DOES gt VOCABULARY STATE R gt CR gt lt SIGN TYPE IMMEDIATE INLINE NUMBER SEARCH SIN
2. One way to describe the stack nl is the TOS n2 is the i second word on the stack n3 the word below that e abed Another way to describe the stack abed repre sents words on the stack The right most character in this case q is the TOS coordinate Two numbers X and Y that represent a point on the screen These must always be positive numbers When pushed on the stack X is always on top of Y LSB Least Significant Bit in some contexts Byte Using the Stack Figure 3 1 illustrates typical use of the stack In this case do A B C defining the variables and leaving the result in A NOTE In this and all examples the numbers appearing in the left most column are ONLY for the discussion of the example and are NOT part of the FORTH input e Wd October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands 1 O Var A declare variable A 2 2 Var B declare B 3 3 Var C declare C 4 B move B to the stack 5 Co move C to the stack 6 add B and C together 7 A save result in A Figure 3 1 Typical Stack Usage pera lines allocate three variables and give them initial values of 0 and 3 Lines 4 and 5 move B and C to the stack C is the TOS Line 6 adds them together leaving the result on the stack and line 7 saves the result in A Figure 3 1 illustrates a very simple stack operation The first three 2 NOTE All keywords tokens are separ
3. Note that each case target must be EXACTLY one word else it dies This means you shouldn t use literals in the case statement Stack 1 0 pop 1 word CEND End a case statement After the selected case entry is exe cuted the program will resume after the CEND statement Stack 1 0 none LSHIFT This word pops two items off the stack TOS is a left shift count ne the word to shift The second word is shifted left the number of places specified by the first word then pushed back on the stack Stack I 0 pop two words push 1 word RSHIFT This word pops two items off the stack TOS is a right shift count n2 the word to shift The second word is shifted right the number of places specified by the first word then pushed back on the stack Stack 1 0 pop two words push 1 word D A double precision signed multiply The top word is multiplied by the second word and the 32 bit result is pushed back to the stack so that the low 16 bits are on the top of stack Stack O0 pop two words push two words ERROR This command returns the address of the error flag word vari able The lower byte of the error flag contains the last error CS October 1984 GRAFIN2 User s Manual Metherzs FORTH code the upper byte contains the number of errors since the flag was reset The user is responsible for resetting this flag SUMMARY TABLES The following 10 tables summarize most of the keywords primi tives and operators found in Me
4. default size of the cursor is 33 by 33 pixels set by INIT GRAFIN Use the CURSOR SIZE command to change the size of the cursor The cursor remains on the screen until removed by INIT GRAFIN2 or CURSOR OFF Related Command E CURSOR OFF CURSOR ON INIT GRAFIN2 SET CURSOR SIZE 2 2 July 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary CURSOR OFF Removes the cursor from the screen Cursor Tracking Command Hex 3F Decimal 63 Arguments None Bytes Returned None Description CURSOR OFF removes the cursor from the screen Generally you will want to remove the cursor whenever you plan to cursor or else move it out of the way and draw over the cursor a shadow image of the cursor s pixels will remain at that location Related Commands CROSSHAIR CURSOR CURSOR ON INIT GRAFIN2 RUBBERBAND BOX RUBBERBAND LINE SKETCH July 1984 23 GRAFIN2 Command Dictionary GRAFIN2 User s Manual CURSOR ON Displays the currently selected cursor Cursor Tracking Command Hex 30 Decimal 48 Arguments None Bytes Returned None Description CURSOR ON displays the most recently selected cur sor While displayed the cursor tracks the mouse The cursor can be a crosshair cursor ihe default a rubberband line a rubber band box or a sketching cursor Select the cursor with the CROSSHAIR CURSOR RUBBERBAND BOX RUBBERBAND LINE or SKETCH commands The INIT GRAFIN2 command selects a 33 by 33 pixel
5. mov P2 20 new draw a new cursor 21 Figure 3 8 Implementing the TV Cursor seen by the cursor to the receiver area on the Omega screen Bltup is called with an XY coordinate on the stack Lines 5 and 6 over over and xsave ysave Il copy the coordinates and save them away in the variables zsave and ysave for temporary storage Line 7 calls exhair which replaces the XY with the commands needed to draw a complement mode cross hair cursor on the stack In line 8 we push the Omega PIXBLT instruction to the stack the opcode and three parameters Note the order that we push the parameters and opcode We now push the MOV P2 instruc tion to the stack in line 9 with the fixed address of 1FFh 1FFh This is the destination of PIXBLT instruction Finally in line 10 we October 1984 3 15 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual retrieve the cursor position from xsave and ysave and use it with MOV P1 the source of the PIXBLT When the stack is unloaded via sexec the commands sent to the Omega are 1 MOV P1 to current tablet position 2 MOV P2 to 1FFh 1FFh 3 PIXBLT a rectangle from P1 to Pe 4 Draw a cross hair cursor U35 is the installation routine First the cursor is removed from the screen by remove in line 13 We then install bltup as the cursor drawing routine by placing the address of bltup in the vari able ccup When we examine bltup we see that it uses the cross hair cur
6. 2 begins the definition of the routine eum Line 3 pushes a 0 on the stack this will be our accumulator Line 4 pushes the parameters cf the loop onto the stack and begins the Do Loop The Do Loop construction is used to iterate through a sequence of numbers The parameters of the loop 1 and 8 are popped from the stack The T and in the fifth and sixth E get the current iteration count and add it to the accumulator Line 7 ends the Do Loop and line 8 ends the definition of sum7 The routine sum7 exits with the result left on the stack We allo cated no variables since the result would be left on the stack The code in Figure 3 3 executes sum and saves its result in the vari able A which was defined ir a previous example 1 sum7 execute the routine 2 A save the result in A Figure 3 3 Executing the Sum Routine By defining this routine we have now extended the language to include a function that returns ine sum of the first seven numbers 34 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands Implementing the MINMAX Routine Figure 3 4 shows the implementation of a GRAFINZ subroutine minmax Minmax sorts the top two values on the stack bv size waits NOTE In discussing this and the remaining examples the GRAIFIN2 subroutines are referenced in boldface and the variables and pointers are referenced in italics The last section of this chapter lists the GRAF
7. READ Q AND WAIT SET Q MODE July 1984 2 11 GRAFIN2 Command Dictionary GRAFIN2 User s Manual READ Q AND WAIT Reads next entry from button event queue Fvent Queue Command Hex 43 Decimal 67 Arguments None Bytes Returned 6 bytes button ID reserved byte low x high x low y high y Description READ Q AND WAIT reads the next entry from the bullon event queue and removes the entry from the queue Events are read in first in first out order READ Q AND WAIT reports the button ID a byte reserved for future use and the coordinates when the button was hit The coordinates are in screen or tablet coordi nates depending on the SET Q MODE command READ Q AND WAIT is the same as READ Q except when the queue is empty When the queue is empty nothing is reported until an event occurs When the queue is empty READ Q reports a button ID of 00 and the current coordinates You can have more than one READ Q AND WAIT commands pending by issuing several in a row Be sure to read as many 6 byte groups as READ Q AND WAIT commands as issued Otherwise you may get inappropriate data from the Omega The FLUSH Q command clears any pending READ Q AND WAIT commands but not the data that may have been generated but not yet read Example 4A 43 4Ah must precede all GRAFIN2 commands 01 00 button 1 was hit reserved byte 2C 0i X coordinate 12Ch C8 00 Y coordinate C8h Related Commands READ Q SET Q MODE 2 12 July 198
8. a bounding box for clip and wrap modes GRAFIN sets a default bounding box according to the hardware 5 a July 1984 B1 APPENDIX C METHEUS FORTH TAR This appendix summarizes the Metheus version of FORTH used in GRAFIN2 Refer to a FORTH reference manual for more information about FORTH The following terms are used throughout the appendix TOS The top word on the FORTH Evaluation stack Each word on the stack is 16 bits wide When a byte is popped or pushed on the stack only the lower 8 bits of the word are used ni n2 n3 n4 These are used to refer to words on the stack ni is the TOS n2 is just below it etc LSB Least Significant Bit or Byte MSB Most Significant Bit or Byte SYNTAX CHANGES The following are changes from the normal FORTH syntax VAR FORTH uses VARIABLE Metheus FORTH requires initialized variables For example 10 VAR XPOS CVAR Just like VAR except it allocates a byte of storage instead of a word For example 6 CVAR COUNT CON Standard FORTH uses CONSTANT Metheus uses CON Yor example 752 CON P1 October 1984 LC Metheus FORTH GRAFIN2 User s Manual CCON Just like CON except it allocates a byte of storage instead of a word For example 1 CON ONE GENERAL PURPOSE ADDITIONS These additions are of general interest and are not related to Omega J 0 or GRAF IN2 functions CASE Begin a case statement The TOS is popped and used as an index into the case
9. by READ Q AND WAIT but not yet read by the host are not flushed See comments at READ Q AND WAIT Related Commands EVENT COUNT READ Q READ Q AND WAIT 26 July 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary INIT GRAFIN2 Initialize GRAFIN2 to its power up defaults Environment Command Hex 10 Decimal 16 Arguments None Bytes Returned None Description The INIT GRAFIN2 command initializes the GRAFIN2 environment to the following default conditions Offset Scale maps a 2200 by 2200 tablet to a 1024 by 768 screen Clip Wrap mode clip bounding box is 1024 by 768 pixels Cursor type 33 by 33 pixel crosshair Cursor is erased from screen Button event recognition leading edge mode Coordinates reported screen coordinates Event queue cleared Error status cleared oo oo oo oO INIT GRAFIN2 restores the graphics environment to its power up conditions The last section of Chapter 1 Initializing GRAFIN2 discusses the commands used to change the INIT GRAFIN2 default conditions Related Commands CROSSHAIR CURSOR CURSOR ON FLUSH Q INQUIRE ERROR SET CLIP MODE SET CURSOR SIZE SET OFFSET SCALE SET Q MODE SET SCREEN SIZE SET TABLET SIZE October 1984 27 GRAFIN2 Command Dictionary GRAFIN2 User s Manual INQUIRE ERROR Returns code indicating most recent error Environment Command Hex 25 Decimai 37 Arguments None Bytes Returned 2 bytes error code an
10. examples ere intended as a model for writing your own commands The last sec tion GRAFIN2 Subroutines Variables and Pointers lists the predefined FORTH routines and variables used by GRAFIN2 GRAFIN is written in the Metheus version of FORTH Appendix C is a summary of Metheus FORTH You should refer to the PORTH reference manuals listed in the Preface for detailed information about FORTH FORTH FUNDAMENTALS FORTH is a stack based interpreted language FORTH evajuates expressions by placing values on the evaluation stack applying operators to these values then leaving the result on the stack or saving the result away The evaluation stack is very sirnilar to the stack used by Reverse Polish Notation calculators PORTH is a registered trademark of FORTH inc October 1984 KA Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual Commandes are built up from subroutines which are in turn built from the FORTH core words and Omega instructions Data is pushed on the stack in the reverse order of execution the stack is last in first out Definition of Terms Table 3 1 contains terms used in the discussions and examples that follow Table 3 1 FORTH Terminology stack The FORTH evaluation stack FORTH uses this stack for storing intermediate results FORTH also has a return stack used for subroutine nesting which GRAFIN2 does not use TOS Top Of Stack The top word on the stack ni n2n3n4
11. mode when a button is put in the event queue See SET Q MODE opcode 41h Trigger Flag Mode Level Mode 1 Leading Edge 2 Trailing Edge 3 Both Edges twidth theight Two variables containing the tablet s width and height They are used by xfinit in calculating the tablet to screen conver sion They are initially set to 2200 by 2200 Summa bit pad size If this is not your tablet size you can use SET TABLET SIZE opcode 12h to put the correct values into these October 1984 3 23 Writing Customized GRAKINZ Commands GRAFIN2 Users Manual variables If you change these vaiues you must call xfinit zanchor yanchor Two variables used only inside the cursor tracking routines If you write a custom cursor you can use these for temporary storage xscale xoffset yscale yoffset Four variables containing the scale and offset values used to transform the tablet coordinates to screen coordinates See the SET OFFSET SCALE 20h command in Chapter 2 for their format Also see size_init Pointer Variabies These variables point to routines to execute coup ccdown These variables are set with the addresses of the routines that draw and erase the cursor Each routine is called with the current cursor position on the stack X on top Each routine replaces the coordinates with a set of Omega instructions If you need to install a routine that does nothing in one of these variables remember that the routine must drop two words the
12. 4 GRAFIN2 User s Manual GRAFIN2 Command Dictionary RUBBERBAND BOX Selects rubberband box style cursor Cursor Tracking Command Hex 33 anchor Decimal 51 anchor Arguments 4 bytes anchor low x high x low y high y Bytes Returned None Description RUBBERBAND BOX generates a rectangle between the anchor point and the cursor The anchor point is given in screen coordinates While displayed the cursor tracks the mouse lhe cursor remains on the screen until removed by INIT GRAFIN 2 or CURSOR OFF The rectangle is drawn in the complement color of the existing pixels Note that when the cursor is exactly on the X axis or Y axis reduc ing the box to a single horizontal or vertical line the line will disap pear due to complementing the pixels twice Placing the anchor point just outside a bounding box eliminates this problem See SET CLIP MODE or SET WRAP MODE Example 4A 33 4Ah must precede the GRAFIN2 command 64 00 X coordinate of anchor 64h 32 01 Y coordinate of anchor 132h Related Commands CURSOR OFF CURSOR ON RUBBERBAND LINE July 1984 2 13 GRAFIN2 Command Dictionary GRAFIN2 User s Manual RUBBERBAND LINE Selects rubber line style cursor Cursor Tracking Command Hex 32 anchor Decimal 50 anchor Arguments 4 bytes anchor low x high x low y high y Bytes Returned None Description RUBBERBAND LINE generates a line between the anchor point and the cursor The anchor po
13. A 2 A 2 Installing the Omega Microcode PROMS aaaeerrrecreee A 3 A 3 The GRAFIN2 Data Transfer Switch ccceeeeeeee A 4 A 4 RS 232 Pin Configuration for GRAFIN2 a c A 6 TABLES UE ee 1 4 1 2 Environment Commands sieren ren Ap E A AAEE 1 5 1 8 Cursor Tracking Commands 0 cceccseeee tee ceneeees eee 1 7 1 4 Event Queue Commands ccc eres eee reeeee sen ennnesteaees 1 8 2 1 Decimal and Hex Scale Factors 0 ee oer 2 18 2 2 Tablet To Screen Conversions Hexadecimal 2 18 2 3 Tablet To Screen Conversions Decimal eree 2 18 3 1 FORTH Terminologie 3 2 3 2 GRAFIN2 FORTH Commands cecccee erste eee c eet eneee eens 3 7 A t Data Rate Selection erce tp cece cece cece a a aN A 5 October 1984 x Contents TABLES C 1 C 2 C 3 C 4 C 5 C 6 C 7 C 8 C 9 Looping and Conditional Primitives Arithmetic and Logical Words Compiler Directives Defining Words 0 eee TZO Word ric oevsededhs deen Memory References Relational Operators Stack Words ceceeeeeeeee eee System Words cece eres C 10 System Variables GRAFIN2 Users Manual ER C 5 EE C8 October 1984 Chapter 1 OVERVIEW This chapter contains four sections Definition of terms used in this manual The GRAFIN2 commands listed by function A discussion of the GRAFIN2 initialization commands An example of G
14. ACE This manual is for new users of GRAFIN2 GRAFIN2 replaces the earlier GRAFIN option This manual describes the commands and features of GRAFIN2 It assumes ihat you know how to use the Omega Display Controller and your graphics input device You do not need to know how to use GRAFIN GRAFIN2 is an optional hardware interface package for Omega display controllers GRAFIN2 is compatible with all host interfaces that support the 0300 0400 and 500 series Display Controllers prog graphics tablet or mouse GRAFIN2 supports the Summagraphics tablet and mouse and GTCO tablet GRAFIN2 commands are used in programs to allow input from a t GRAFIN2 is not compatible with GRAFIN I he differences between them and the installation procedures for GRAFIN2 are discussed in Appendix A and B MANUAL OVERVIEW This manual contains three chapters and three appendixes o Chapter 1 defines terms and discusses the GRAFIN2 commands by function o Chapter 2 discusses the GRAFIN2 commands in detail o Chapter 3 illustrates how to write customized GRAFIN2 commands using the Metheus version of FORTH o Appendix A contains the installation procedure for GRAFIN2 o Appendix B describes the differences between GRAFINe and GRAFIN o Appendix C summarizes Metheus FORTH 1Summagraphics is a registered tradename of Summagraphics Corporation GTCO is a regisiered tradename of GICO Corporation SFORTH isa registered trademark of FORTH inc O
15. CALE SET SCREEN SIZE SET TABLET SIZE o Set up a bounding box on the screen SET CLIP MODE SET WRAP MODE Inquire the error status of the system INQUIRE ERROR Inquire the version of the firmware INQUIRE VERSION o Initialize the tablet WRITE TABLET Face OR ore E The environment commands are summarized in Table 1 2 TABLE 1 2 Environment Commands Hex Decimal Opcode Opcode INIT GRAFIN2 10 none INQUIRE ERROR 25 none INQUIRE VERSION 26 none Name Arguments SET CLIP MODE 22 BK Y Xa Y SET OFFSET SCALE 20 8 c SET SCREEN SIZE 11 4 d SET TABLET SIZE 12 4 d SET WRAP MODE 21 8 X Y Xa Y WRITE TABLET 24 e a first byte error code second byte error count b first byte version code second byte reserved c 2 bytes each 16 bit 2 s complement K Offset X Scale Y Offset Y Scale d 2 bytes each of width and height of screen or tablet rel variable number of bytes device dependent The Arguments and Returns columns in Table 1 2 indicate the number of bytes if any required as input or returned as output For example 8 X Y X Y means that the command opcode is followed by eight bytes of information in this case the coordinates October 1984 1 6 Overview GRAFIN2 User s Manual four bytes of one corner of the bounding box and the coordinates four bytes of the opposite corner of the bounding box Cursor Tracking Commands The cursor tracki
16. GLE TOKEN CURRENT LBP MODE 3 October 1984
17. GRAFIN2 USER S MANUAL 004 02704 01 Copyright 1984 Metheus Corporation 5510 N E Elam Young Parkway Hillsboro OR 7123 DISCLAIMER The information in this manual is subject to change without notice Methcus Corporation makes no warranty of any kind with regard to this material including but not limited to the implied warranties of merchantability and fitness for a particular purpose Metheus Corporation assumes no responsibility for any errors that may appear in this manual Metheus Corporation makes no commit ment to update nor to keep current the information contained in this document Metheus Corporation assumes no responsibility for the use of any circuitry other than circuitry embodied in a Metheus product No other circuit patent licenses are implied Metheus software products are copyrighted by and shall remain the property of Metheus Corporation Use duplication or disclosure is subject to restrictions stated in your Metheus software license No part of this document may be copied or reproduced in any form or by any means without the prior written consent of Metheus Cor poration METHEUS AXIA FLASH fill and PIXBLT are trademarks of Metheus Corporation Revision Revision History Date Number 8 8 00 First Issue Supports version 2 5 of the 7 84 Q500 microcode and version 3 6 of the Q400 and 2300 microcode 01 Adds two new commands for Ltablet to 10 84 screen conversions Adds a new cha
18. IN2 subroutines variables and pointers 1 minmax define the routine 2 over over copy the two top items on the stack 3 gt compare the 2 numbers replece with T F 4 if test if n2 is greater than n1 5 swap reverse the order 6 then end of If statement 7 exit with larger number on TOS Figure 3 4 Implementing the Minmax Routine Minmax expects two numbers on the stack and when it exits the larger number is on the top of stack The first line starts the definition of minmax Line 2 copies the two numbers on the stack so that we now have four numbers on the stack If the values were ab the stack now contains abab The gt in line 3 compares the top two numbers and replaces them with a True False flag a 9 if n2 was less than nl else a 1 In FORTH 0 is false non zero is true The stack now contains either ab0 or abt The if state ment in line 4 pops the T F flag left by the gt operator ff the second number was bigger line 5 swaps tne two numbers icit on the stack Line 6 ends the if statement and line 7 ends the definition of minmax Learning FORTH Now that you have seen some simple examples of FORTH you may want to try it yourself There are two ways to learn FORT on your Omega system The first method disables the GRAFIN2 firmware October 1984 ay Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual and allows you to directly access the FORTH int
19. N2 you will want to initialize the sys S tem and possibly change the default conditions This section looks at the defaults of the INIT GRAFIN2 command and discusses the commands used to change the default conditions INIT GRAFIN2 Initializes the graphics input environment SET SCREEN SIZE or SET TABLET SIZE Changes the defauit value of the screen or tablet size used in mapping o SET OFFSET SCALE Adjusts the mapping of the tabiet to the screen o SET Q MODE Selects the button event type and coordinate sys tem o Cursor Tracking Commands Selects and displays a cursor o SET CLIP WRAP MODE Selects the mode and defines a bound ing box INIT GRAFIN2 maps a 2200 by 2200 tablet to a 1024 by 768 pixei reen If your tablet or screen is a different size use SET SCREEN ZE or SET TABLET SIZE to change these default values You can 1 8 October 1984 GRAFIN User s Manual Overview also use SET OF FSET SCALE INIT GRAFINe clears the button event queue defines a button event as a leading edge and specifies that screen coordinates are sent to the host To select another button edge type or change to tablet NPOART coordinates use SET Q MODE INIT GRAFINe2 selects a 33 by 33 pixel crosshair cursor and erases the cursor from the screen To display the crosshair cursor use CURSOR ON or CROSSHAIR CURSOR To change the size of the crosshair cursor use SET CURSOR SIZE To select a different cur sor and display it on the scre
20. RAFIN2 use GOCO DEFINITION OF TERMS The GRAFIN2 interface accepts graphics input from a bit pad tablet or mouse In this manual the input device is referred to as the tablet The tracking part of the tablet the stylus puck or mouse is referred to in this manual as the mouse The mouse s position is indicated on the screen by the cursor GRAFIN2 keeps track of button events Button event information includes which button on the mouse was pressed the button ID and the coordinates when the button was pressed Button events are stored in the button event queue Events are read from the queue in first in first out order A button event can be defined as the push of a button leading edge mode the release of a button trailing edge mode the button held down level mode or the push and release of the button both edge mode two events are recorded The button ID byte is identical to the data format byte sent from the tablet The button ID is formed from the button information bits in the Summagraphics Bit Pad One Binary Data Format bits FO through F3 the SummaMouse Bit Pad One Data Format bits L M and R or the GTCO DIGI PAD 5 High Resolution Format bits PB1 PB2 PB4 PB8 and PBA Figure 1 1 illustrates these formats Refer to your tablet manual for information on interpreting the button ID October 1984 1 1 Overview GRAFIN2 User s Manual Summagraphics Dn Pad One P 1 F3 Binary Data Format S
21. See SET OFFSET SCALE opcode 20h in Chapter 2 xhair_set l Removes the cursor and installs the crosshair cursor as the current cursor type by setting ccup and ccdown to the address of exhair 322 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands Scaler Variables cheight curdth Two variables containing the height and width of the current bounding box as set by SET WRAP MODE and SET CLIP MODE opcodes 21h and 22h Also see size_init ecount Tells how many button events are stored in the event queue 0 means empty hiXclip hiYclip loXclip lo Yclip Four variables that define the bounding box for the clip and wrap routines HiXclip gt loXclip and hiYclip gt loYclip or you will get unpredictable results Also cwidth and cheight must be set so that they agree with the bounding box These vari ables are set by SET WRAP MODE and SET CLIP MODE opcodes 21h and 22h and are also set by size_init swidth sheight Two variables containing the screen s width and height They are used in computing the tablet to screen conversion They are initially set to 1024 by 768 If this is not your screen size use SET SCREEN SIZE opcode 11h to put the correct values into these variables See also routines size_init and xfinit syncon Enables an Omega SYNC instruction between cursor draw and erase when this variable is set to 1 Most cursors look better with this variable set to 1 trig Selects the trigger
22. X and Y from the stack clpwrp Contains the address of either the clip routine or the wrap rou tine You would typically set it by wrap clpwrp or clip clpwrp scaleat Points to the routine that converts tablet coordinates to screen coordinates for bution reporting GRAFIN2 normally sets this to null for tablet coordinates or tosereen for screen coordinates uscaleat Points to a user defined position scaling routine The routine is called after the current position is converted from tablet to screen coordinates After the routine is called the result is clipped or wrapped This variabie is normally set to null and 324 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands can only be changed by a user created GRAFIN2 commana routine uscaleat points to is called with XY on the stack must return with an XY on the stack Also see toscreen October 1984 The and APPENDIX A GRAFIN2 INSTALLATION This chapter explains how Lo install GRAFIN2 in your Omega sys tem The GRAFIN2 update package includes the GRAFIN2 board and eight new PROMs for the Omega display controller board Specifically the instructions in this chapter describe CO 1 2 3 Position of the GRAFIN2 board Replacing the microcode PROMs in the Omega display con troller board Selecting GRAFIN 2 data rates Connecting the graphics tablet CAUTION Only qualified service personnel shoul
23. al WRITE TABLET Sends initialization bytes to tablet or mouse Environment Command Hex 24 init byfes 1B Decimal 36 init bytes 27 Arguments init bytes device dependent bytes to initialize spe cial functions of the tablet Argument is terminated by an ASCII escape 1Bh Bytes Returned None Description WRITE TABLET allows you to send initialization bytes to the tablet for example to change the sampling rate Refer to the manual of your tablet for the appropriate bytes In most cases you will not need this command The command is terminat ed by an ASCII escape code 1Bh Related Commands None 2 26 October 1984 Chapter 3 WRITING CUSTOMIZED GRAFIN2 COMMANDS This chapter shows by example how to write customized GRATIN2 commands using the Metheus version of FORTH In this chapter we assume that you are an experienced programmer and that you want to expand the functionality provided by GRAFIN2 If the exist ing GRAFIN2 commands meet your needs you do not have to read this chapter The chapter contains three sections o FORTH Fundamentals o Command Examples o GRAFIN2 Subroutines Variables and Pointers The first part FORTH Fundamentals introduces FORTH with seme simple examples The second section Cornmand Examples con tains examples with comments The section shows you the imple mentation of the Rubberband Line cursor the Sketch cursor a TV cursor and some grid drawing routines The
24. ap put X on TOS turn grid on U18 remove remove the cursor hget xgrid init the X and Y grid spacing hget ygrid grid uscaleat ifon turn grid off U19 remove null uscaleat ifon Figure 3 9 Implementing Grid Drawing Routines October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands draw a grid on the screen in current color 27 U81 28 hget xgrid init the X and Y grid spacing 29 hget ygrid 30 swidth 0 do draw vertical lines 31 draw 32 OIpl 33 sheight 1 p2 34 sexec drop 35 xgrid loop 36 sheight 0 do draw horizontal lines 37 draw 38 10pl 39 I swidth p2 40 sexec drop 41 ygrid loop 42 Figure 3 9 Cont Implementing Grid Drawing Routines GRAFIN2 SUBROUTINES VARIABLES AND POINTERS This section contains subroutines variables and pointers used by GRAFINe Entries are arranged alphabetically within each group ing Variables and pointers are referenced by italics and subrou tines by bold text GRAFIN2 Subroutines anchor Reads an XY coordinate from the host and initializes the vari ables zanchor and yanchor with the values bget Gets a byte from the Omega fills leading zeros to 16 bits and returns that word as the TOS October 1984 3 19 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual bsend Sends the lower byte of the TOS word to the Omega button Retur
25. ated by spaces or tabs In Metheus FORTH tokens differ by length and by the first three characters Case is not considered lower case is converted to upper case There and theory differ in length but treat and trees are considered identical Comments are within parentheses Be sure to include the right parenthesis Extending FORTH With Subroutines Because FORTH is a threaded interpreted language it is very easy to extend the language by defining new subroutines Metheus pro vides some subroutines for use with GRAFIN2 these are discussed in the last section of this chapter Once a routine is defined it can be called by other routines the same way FORTH core words or previously defined routines are called The Mctheus FORTH core words are covered in Appendix C Figure 3 2 shows a subroutine that finds the sum of the numbers 1 through 7 October 1984 33 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual 1 decimal set base 10 2 sum7 define a routine named sum7 3 0 init the accumulator 4 8ido startat 1 count till we reach 8 5 I get the current iteration count 6 add it to our accumulator 7 loop bump the iteration count exit if 8 D end definition of routine eum Figure 3 2 Sum Subroutine This summing example illustrates the construction of a simple sub routine The first line sets the radix of the numbers in this case decimal Line
26. ates are reported as screen or tablet coordinates Only the lower two bits of the detect byte are significant only the lowest bit of the report byte is significant All other bits are reserved for future use and should be set to zero Detect byte values 0 level mode events are recorded while a button is held down and the coordinates change 1 leading edge mode button pushed 2 trailing edge mode button released 3 both edge mode two events button pushed and released The default for INIT GRAFIN is leading edge detection value 1 FReport byte values 0 reports in tablet coordinates 1 reports in screen coordinates The default for INIT GRAFIN2 is screen coordinates value 1 2 20 July 1984 GRAFINe2 User s Manual GRAFIN2 Command Dictionary Example 4A 41 4Ah must precede all GRAFIN2 commands 00 01 Selects level button input and screen coordinates Related Commands INIT GRAFIN2 READ CURRENT POSITION READ Q READ Q AND WAIT July 1984 221 GRAFIN2 Command Dictionary GRAFIN2 User s Manual SET SCREEN SIZE Sets screen size for mapping Environment Command Hex 11 screenwidth screenheight Arguments 4 bytes screenuidth low width high width screenheight low height high height Bytes Returned None Description SET SCREEN SIZE maps the default tablet size to the screen size specified in the arguments The default tablet size is 2200 by 2200 pixels The tablet size can be changed
27. crosshair cursor but does not display it on the screen The cursor remains on the screen until removed by INIT GRAFIN2 or CURSOR OFF Related Commands CROSSHAIR CURSOR CURSOR OFF INIT GRAFIN2 RUBBERBAND BOX RUBBERBAND LINE SET CURSOR SIZE SKETCH 24 July 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary EVENT COUNT Returns the number of events in the event queue Event Queue Command Hex 40 Decimal 64 Arguments None Bytes Returned 2 bytes low high of event count Description EVENT COUNT tells you the number of items in the event queue The event queue holds up to 100 events Events that occur after the queue is full are ignored You can check if the queue has overflowed with the INQUIRE ERROR command Events are read from the queue in first in first out order EVENT COUNT returns a 16 bit two s complement number low byte high byte Example 4A 40 4Ah must precede all GRAFIN2 commands 1A 00 The event queue contains 26 button hits Related Commands FLUSH Q INQUIRE ERROR July 1984 25 GRAFIN2 Command Dictionary GRAFIN User s Manual FLUSH Q Clears the button event queue Event Queue Command Hex 45 Decimal 69 Arguments None Bytes Returned None Description FLUSH Q deletes all information in the button event queue and resets the count in EVENT COUNT to zero Any pending requests from the READ Q AND WAIT command are aiso flushed However data generated
28. ctober 1984 vii Preface GRAFIN2 User s Manuai NOTE If you are installing GRAFIN2 or upgrading GRAFIN to GRAFIN2 you should read Appendix A first Installation should be per formed by a qualified service person only RELATED PUBLICATIONS AXIA Graphics Package User s Manual Order Number 004 01086 FORTRAN Opcode Library User s Manual Order Number 004 01705 0400 User s Manual Order Number 004 01085 Q500 User s Manual Order Number 004 02207 The MicroFORTH Primer FORTH Inc Manhattan Beach CA 1976 FORTH Fundamentals Dilitheum Press Beaverton OR 1983 viii L CONTENTS CHAPTER 1 OVERVIEW Definition Ol Terms aena e ieee ate Aere oa gaat a cng erty ta oh wee gee GRAFING Commands a a 5 00 role Wiech date E ek renters Environment Commands ccecceeceece cnet ee cnet este seeeeeeeeineees Cursor Tracking Commands 0 cccccce eee cece tenet ee ttereet eerie Event Queue Commands ccceeeccceeee eee ee rete ne eee een eneeeteneied Tnitializinig GRAPING eet EENS ENNEN me EE EAR GRAFING Example earannan E EAEE EAEE ETETA CHAPTER 2 GRAFIN2 COMMAND DICTIONARY Crosshair Cursor mierne eei teer An SRE AA EAE a ED E Cursor OFF aed ise ia aa a ei A EE Eer Cursor O a EEEE E ET A Byemt E EE Fish ET mit GRAFIN saoe esciecouandoadee cs esl cetis de E Ea a A Inquire Error ssssssseeerrerertererereresereves EE Inquire Version EE Read Current Position 0cccccccccc
29. d attempt any procedure where the covers must be removed Read and follow the instal lation instructions carefully Failure to properly install the GRAFIN2 board or microcode PROMs could result in improper operation or equipment damage to your Omega system Unplug the Omega from the AC power source Remove the top cover by removing the screws that hold it in place Remove the interface board and if you are upgrading from GRAFIN also remove the GRAFIN board Figure A 1 illustrates the position of the interface and GRAFIN2 GRAFIN boards July 1984 Al GRAFIN Installation GRAFIN2 User s Manual OMEGA CHASSIS Back J1 on Q300 2400 not marked on 500 Omega Display Controller Board F 0080 Figure A 1 Position of the Interface and GRAFIN2 Boards 4 Replace the Omega microcode PROMs Figure A 2 illustrates the location of the microcode PROMs for the 0300 0400 and for the 0500 Note the arrangement of the PROMs WARNING Be sure that each PROM is in the correct socket and is correctly oriented Failure to install the PROMs correctly may damage the PROMs and result in improper operation A2 July 1984 GRAFIN2 User s Manual GRAFIN2 Installation 06 CH a Q N Q Q 300 amp 400 500 Display Display Controller Controller Board Board Front Front SRS F 0079 Figure A 2 Installing the Omega Microcode PROMs e
30. d error count Description INQUIRE ERROR returns two bytes The first byte con tains the code of the most recent error and the second byte con tains the number of errors up to 2d6 since the iast INQUIRE ERROR command The error codes are 0 no error when error count byte is 0 macro compilation error when error count byte is non 0 1 cold start error 2 warm start error 3 stack error 4 unknown FORTH command 5 reserved 6 event queue overflow too many button hits 7 unknown GRAFINe command These errors are informational and non fatal with the exception of errors 1 2 and 3 However it is unlikely you will ever see those three errors Example 4A 25 4Ah must precede all GRAFIN2 commands 06 OC Indicates 12 errors event queue overflow was most recent Related Commands EVENT COUNT 28 July 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary INQUIRE VERSION Returns the GRAFINe firmware version Environment Command Hex 26 Decimal 38 Arguments None Bytes Returned 2 bytes version code and reserved byte Description INQUIRE VERSION reports the current implementa tion version of the GRAFIN2 firmware The first byte returns the GRAFINE firmware version number The second byte is reserved for future use Example 4A 26 4Ah must precede all GRAFIN2 commands 10 00 Indicates version 1 0 of the GRAFIN firmware Related Commands None July 1984 29 GRAFIN2 Command Dictionar
31. ds ifon Redraws a cursor on the screen if remove erased one Ifon calls new to do this init Removes the cursor then resets all variables to their power up stale See INIT GRAFIN2 opcode 10h in Chapter 2 User defined routines are not affected minmax Sorts the top two numbers on the stack so that the larger is on the TOS and the smaller is beneath it new Checks if a cursor is displayed on the screen If not new pushes the current XY coordinates on the stack It then com putes the new cursor drawing data and instructions by calling the routine whose address is in ccup New leaves the Omega data and instructions on the stack The stack contents are later automatically sent to the Omega by sexec null Does nothing and is the default routine pointed to by uscaleat ppad Sends the low byte from the TOS to the tablet devices qflush Discards any data in the event queue remove Checks if a cursor is displayed on the screen If so remove pushes the cursor s XY position to the stack It then removes the cursor by calling the routine whose address is in ccdown Remove then invokes sexec to send the instructions and data stored on the stack to the Omega sexec Pops instructions and data from the stack and sends thern to the Omega until a zero opcode is found Sexec leaves the zero on the stack and also returns a garbage word on TOS Sexec is invoked automatically at 60Hz size_init Uses the top two words on the stack
32. e October 1984 Table C 6 Memory References Function Save n2 at address n1 Add n2 to variable whose address is nl Set variable whose address is n1 to 0 Set variable whose address is n1 to 1 Move variable whose address is n1 to n1 Set the character variable whose address is n1 to n2 Add n2 to the character variable whose address is ni Move the character variable whose address is nl to n1 Set the character variable whose address is n1 to 0 Set the character variable whose address is n1 to 1 Table C 7 Relational Operators Function Compare TOS to zero lt 0 sets true on TOS else false Compare TOS to zero 0 sets true on TOS else false Compare top two words on stack replaces words with true false Compare top two words on stack replaces words with true false Compare top two words on stack replaces words with true false Metheus FORTH GRAFIN2 User s Manual Table C 8 Stack Words Name STACK Mr OO 2DUP 20VER 2SWAP ASPACE CJOIN CSPLIT DROP DUP H I J K LROT OVER RROT SWAP c8 Function Push a 0 to the stack Reset the stack pointer Lo power up value Push a 1 to the stack Push a 2 to the stack Copy nl to TOS twice Copy n3 to TOS Swap TOS and nd Push a space character to the stack Merge high byte of n2 and low byte t Split TOS so high byte is in n2 low in n1 Drop the TOS Duplicate the TOS Get value of previous iteration counter to stack
33. e any cursor that may currently be visible by calling remove set ccdown and ccup and draw the new cursor with the new routine 1 U35 GRAFIN2 names begin with U 2 remove removes a cursor if visible 3 Draw ccup instails Draw 4 Erase ccdown installs Erase 5 new draws the new cursor Bi end definition of U35 Figure 3 5 An Installation Routine Figure 3 5 illustrates an installation routine that defines a new 38 October 1984 oo GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands cursor as opcode 35h Assume that we have previously defined the Draw and Erase routines The first line starts the definition of the routine By convention all GRAFIN2 commands are named Unn where nn is a hex number To execute the command you would enter 4Ann Remove in line 2 pushes the cursor s coordi nates on the stack and removes the current cursor if one is visible At this point ccdowm contains the last cursor erasing routine used Line 3 takes the address of Draw and stores it in the pointer variable ccup Likewise line 4 puts the address of Erase in ccdowm New in line 5 causes the new cursor to be drawn When new exe cutes it places the current coordinates on the stack X on top Y as the second word then calls the Draw routine Likewise remove places the current coordinates on the stack then calls the Erase routine After the Draw or Erase routine exec
34. ee July 1984 GRAFIN Installation GRAFIN2 User s Manual 5 6 AA Select GRAFIN2 Data Rates GRAFIN2 interface boards are set at the factory for 9600 baud If you need to change this setting follow these instructions Find the 8 position switch near the center of the GRAFIN2 board Four positions numbered 1 through 4 in Figure A 3 select the transfer rates This figure shows the default switch positions selecting 9600 baud Tablet Eight position Switch Connector set for 9600 Baud Eug Interface Board Connector 12345678 Off Off F 0014 Figure A 3 The GRAFIN2 Data Transfer Switch Select the new baud rate from Table A 1 and set the switches accordingly July 1984 GRAFIN2 User s Manual GRAFIN Installation Table A 1 Data Rate Selection Baud Switch Settings Rate 1 2 3 4 unused 1 1 1 1 19 2K W 1 1 1 9600 1 0 1 1 7200 0 0 1 1 4800 1 1 0 1 3600 0 1 0 1 2400 1 0 0 1 1800 0 0 0 1 1200 1 1 1 0 600 0 1 1 0 300 1 O 1 0 150 0 0 1 0 134 5 1 1 6 0 110 0 1 D 0 75 1 0 Q 0 50 0 0 0 0 NOTE 0 Off 1 On 7 Switch 5 determines resolution format When set in the 0 off position the GTCO binary high resolution format is selected The 1 on position selects the Summagraphics Bit Pad format July 1984 AS GRAFIN Installation GRAFIN2 User s Manual Refer to the tablet manual for compatibility information The factory setting is 1 selecting t
35. eeceeeceeteeeree ee eet eneeenpeeteneeeeennes Read Qrar een ei a i Ea E AA TEE Read Qand Wait eeen ank aE aa T ATE EE ens esas Rubberband Box aae dE Zeen ed aea SEON A Rubberband Lines e eeiieeg geet ea wh dee EE AAN A E e EN Set Clip Mode EE Set Cursor Size naene a nA E E AAEE EATE NE a ces Set Offset SCAale ea Greet ai E E hy TT EEA AAAA Set O Mode cornete a rki ead R S Er A R EER RA A Set Screen Sie raare e aan a A O aA Set Tablet Size ANE Leeder nore e Set Wrap Mode E SK EECH ugeet EE Ae Bee eebe Eege Nee Write Tablet oo rasie d e EA ege ENEE ad ed DEEN October 1984 ix Contents GRAFIN2 Users Manual CHAPTER 3 WRITING CUSTOMIZED GRAFIN2 COMMANDS FORTH Fundamentals Nee EC esse sesso EE EENS EN 3 1 Definition Of Terms td cians ates eater ease wins Pee ea eee ae 3 2 Using the Stack eege eege ae Bebe 3 2 Extending FORTH With Subroutines 0 cceeeeeeeeseteeeeeeee 3 3 Implementing the MINMAX Routine cece 3 5 Lediming FORTH oaair eaen a ESN EAER AA cas stead Soci 3 5 Method One Hardware Direct eeescerressrrrerrerererrrrererers 3 6 Method Two Downloading 3 7 Command BXampleS odati e aE E E ENS 3 8 Writing Custom Cursors sisari iiureraces ioneina AEE E n TaS 3 8 Implementing the Rubberband Line Cursor ees 3 9 Stack Management With SEXEC oo cece terete eee eee 3 11 Implementing the Sketch Cursor esseeeeeeteteeteeees 3 12 Implementing the TV C
36. en use RUBBERBAND BOX RUBBER BAND LINE or SKETCH CURSOR OFF erases the cursor from the screen CURSOR ON displays the most recently selected cursor INIT GRAFIN selects clip mode with a 1024 by 768 pixel screen as the bounding box To set a different bounding box use SET CLIP MODE To change to wrap mode and set a bounding box use SET WRAP MODE GRAFIN2 EXAMPLE Figure 1 3 contains sample GRAFIN2 commands followed by com ments The numbers in the left most column refer to the com ments and are not part of the GRAFIN2 commands October 1984 1 9 Overview GRAFIN2 User s Manual 1 4A 10 INIT GRAFIN2 2 4A 11 00 05 00 04 SET SCREEN SIZE 3 4A 41 02 00 SET Q MODE 4 4A 33 64 00 32 01 RUBBERBAND BOX 5 4A 44 READ CURRENT POSITION 4 bytes returned Move the mouse around the tablet and press a few buttons 6 4A 42 READ Q 6 bytes returned 7 AA 45 FLUSH Q 8 4A 3F CURSOR OFF OV yj 4E 00 60 Sct color 0 black and clear screen Figure 1 3 Sample of GRAFIN2 Commands The code in the above example performs these actions 1 Initializes GRAFIN2 2 Adjusts the mapping to an 1280 by 1024 screen GEN 3 Sets the queue mode to trailing edge and tablet coordinates 4 Enables and displays a rubberband box cursor 5 Reads the current position of the mouse 6 Reads information from the event queue 7 Clears the event queue 8 Removes the cursor from the screen 9 Sets co
37. erpreter on the GRAFIN2 card Routines developed this way are lost when you enable GRAFIN2 again This method is intended only for learning FORTH The second method downloads routines to the FORTH interpreter with one of the GRAFIN2 FORTH commands opcodes 50h 51h 52h or 53h The GRAFIN2 FORTH commands like all GRAFIN2 com mands must be preceded by opcode 4Ah Your routines are stored in the user dictionary NOTE The stack and the user dictionary share approximately 1200 bytes of memory on the GRAFIN2 card The stack and diction ary are located at opposite ends of memory and each grows toward the middle If you define too many routines the stack area may become so small that the system crashes METHOD ONE HARDWARE DIRECT The first method of learning FORTH requires you to remove SE cover of your Omega and turn off switch 7 of the data iransisr switch on the GRAFIN2 card See Appendix A for instructions Refer to Figure A 3 for the location of the switch Switch 7 OFF dis ables the normal GRAFIN2 firmware and allows you to communicate directly with the FORTH interpreter on the GRAFIN2 card You can plug your terminal into tablet port J4 on the back of the Omega Be sure the baud rate of your terminal matches the baud rate of the Omega With switch 7 OFF all input from J4 goes directly to the FCRTH interpreter A control C will usually break you out of a FORTH program and return control to the interpreter If your p
38. from the mouse There are two types of event queue commands o Commands to manage the event queue itself EVENT COUNT FLUSH Q SET Q MODE o Commands that return event information to the host READ CURRENT POSITION READ Q READ Q AND WAIT EVENT COUNT keeps track of the number of events in the event queue If the queue count exceeds 100 new events are ignored and a queue overflow error will be indicated by the INQUIRE ERROR command FLUSH Q clears the event queue Use the SET Q MODE command to select which edge is recorded and whether tablet or screen coordinates are reported The event queue commands are summarized in Table 1 4 The Arguments and Returns columns indicates the number of bytes if any required as input or returned as output X Y indicates coor dinates October 1984 1 7 Overview GRAFIN2 User s Manual TABLE 1 4 Event Queue Commands Hex Decimal Name Opcode Opcode Arguments Returns EVENT COUNT 40 64 none 2 a FLUSH Q 45 69 none none READ CURRENT POSITION 44 68 none 4 X Y READ Q 42 66 none amp b READ Q AND WAIT 43 67 none 6 b SET Q MODE 41 65 2 c none nal first byte event count second byte reserved nb first byte button ID second byte reserved third through sixth byte X Y coordinates c first byte type of button edge recorded second byte screen or tablet coordinates reported INITIALIZING GRAFIN2 In general when you use GRAFI
39. h C8 00 Y C8h Related Commands SET WRAP MODE July 1984 2 15 GRAFIN2 Command Dictionary GRAFIN2 User s Manual SET CURSOR SIZE Sets the size of the crosshair cursor Cursor Tracking Command Hex 23 halfwidth halfheight Decimal 35 Aalfurtdt Arguments 4 bytes halfwidth low halfwidth high halfwidth halfheight low halfheight high halfheight Range is 1 to 2047 ih to 7FFh pixels Bytes Returned None Description SET CURSOR SIZE aiiows you to select the size of crosshair cursor The actual cursor size is 2 x halfwidth or halfheight 1 The default size of the crosshair cursor is 33 by 33 pixels tha Vlitc Example To make a 45 by 45 2Dh by 2Dh pixel cursor 4A 23 4Ah must precede all GRAFIN2 commands 16 00 halfwidth 16h C 16 00 halfheight 16h i Related Commands CROSSHAIR CURSOR SKETCH 2 16 July 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary SET OFFSET SCALE Maps the tablet to the screen Environment Command Hex 20 X Offset X Scale Y Offset Y Scale Decimal 32 X Offset X Scale Y Offset Y Scale Arguments 8 bytes X Offset low X offset high X offset X Scale low X scale high X scale Y Offset low Y offset high Y offset Y Scale low Y scale high Y scale Bytes Returned None Description The SET CFFSET SCALE command sets values used to map tablet coordinates to screen coordinates The tablet to screen conversion equations are Scree
40. h Cursor October 1984 2 13 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual called with XY coordinates on the stack Line 5 calls the routine exhair Cxhair replaces the coordinates with the appropriate Omega moving and drawing instructions to create a complemented crosshair cursor The epos Loscreen in line 6 takes the current tablet position and converts it to screen coordinates Line 7 checks the button status If a button is being pressed line 8 0161 rrot pushes an Omega DRAW instruction then rotates the top three stack entries so that the X and Y are back on the TOS Lines 8 through 13 draw a vector from the last cursor position to the current position The 0753 in line 9 pushes MOV P2 to the stack it will use the X and Y on the stack as data Lines 10 and 11 move the previous cursor position to the stack and store the current position in zanchor and yanchor Then in line 12 MOV P1 is pushed to the stack The last line of the if statement pushes an Omega PATTERN instruction and data to set a solid line The else statement in line 14 updates the cursor s position when no button was pressed Routine U34 installs the SKETCH cursor Xhair_set removes the old cursor and sets ccup and ccdown to the address of exhair Line 20 rr inkup ccup places the address of inkup in ccup New pushes the current coordinates to the stack and calls the routine whose address is in ccup inkup Implementing the TV Curso
41. he Summagraphics Bit Pad for mat i 8 Switches 6 7 and 8 are reserved for future use and should remain as illustrated switches 6 and 7 are on and switch 8 is off 9 After changing switch positions replace boards as in Figure A 1 Replace the top cover and the power cord 10 Connect the input device to the Omega Attach the input dev ice to socket J4 on the back of the Omega The pin arrange ment of the RS 232 connector is illustrated in Figure A 4 Ground Transmit Data to tablet k Receive Data from tablet RTS Request to Send always high CTS Clear to Send ignored DSR Data Set Ready ignored Ground DTR Data Terminal Ready always high ONOORWN A F 0082 Figure A 4 RS 232 Pin Configuration for GRAFIN2 A July 1984 Appendix B GRAFIN AND GRAFIN2 DIFFERENCES GRAFIN2 differs from GRAFIN in the following ways 1 GRAFIN2 stores button hits in the button event queue GRAFIN sends button hits to the host immediately no event queue 2 GRAFIN2 returns six bytes of information about button hits GRAFIN returns five 3 GRAFIN2 allows a choice of four styles of cursor plus varying the size of the default crosshair cursor GRAFIN supports only the crosshair cursor 4 GRAFIN2 keeps the cursor on the screen unless taken down explicitly with the INIT GRAFIN2 or CURSOR OFF commands GRAFIN takes down the cursor whenever a command is exe cuted GRAFIN2 allows you to specify
42. he current Omega drawing color Cursor is not snapped to this grid The size of the grid for either U18 or U81 is given as one byte of X spacing and one byte of Y spacing and stored in zgrid and ygrid defined in lines 2 and 3 Snapping the cursor to the grid means that the cursor moves in discrete jumps The jump size is specified by the XY spacing Snapping uses a feature called filtering One example of filtering is shown in the GRID routine in Figure 3 9 This routine intercepts the tablet data and modifies it before the GRAFIN2 firmware draws the cursor More importantly you can write routines that are unrelated to graphics input The routine U81 also shown in Figure 3 9 simply draws a grid on the screen in the currently selected drawing color The ability to download general purpose routines to the FORT interpreter offers an efficient alternative to host resident software October 1984 217 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual ray m WANS e CO CO Es ageet e 7 8 9 hex set hexadecimal format for numbers O var xgrid declare 2 variables to hold the grid spacing O var ygrid 752 con pl constants for use in grid drawing routine 753 con pe 161 con draw filter the XY on the stack so that it is snapped to the grid grid xgrid 2 get 1 2 the xgrid value add to X dup xgrid mod swap do the same for Y yerid 2 dup ygrid mod sw
43. he final value stop Start of a DO loop Middle of an IF ELSE THEN construct Start of the IF construct Exit a DO loop End of a DO loop 1 is added to the current iteration count End of a BEGIN WHILE REPEAT loop End of a IF construct End of a BEGIN UNTIL Middle of a BEGIN WHILE REPEAT Start a ASCII string End an ASCH string two single quote marks together Move dictionary ad dress of next token to TOS NOTE These commands only work if you are in compile mode They cannot be executed in command mode October 1984 C45 Mctheus FORTH GRAFIN2 User s Manua Table C 4 Defining Words Name Function Begin dictionary definition End dictionary definition CON Assign a constant word CCON Assign a constent byte CVAR Assign a variable byte VAR Assign a variable word Table Ca 1 0 Words Not available to GRAFIN2 application code Name C ASCII CRET DISPLAY ECHO KEY MSG Function Prints the 16 bit number whose address is the TOS Prints the 8 bit number whose address s the TOs Converts low byte of TOS to ASCH Send a carriage return line feed Prints low bytes from successive TOSs until low byte is non ASCII gt 80h Prints low byte of TOS Pushes byte from terminal to TOS Type out a prompt based on the current error flag October 1984 GRAFIN2 User s Manual Metheus FORTH Name OSET 1SET C C OAOT VO C1SET Nam
44. int is given in screen coordinates While displayed ine cursor tracks the mouse The cursor remains on the screen until removed by INIT GRAFIN2 or CURSOR OFF The line is drawn in the complement color of the existing pixels Note that when the cursor is exactly on the anchor point the cur sor will disappear due to complementing the pixels twice Placing the anchor point just outside a bounding box eliminates this prob lem See SET CLIP MODE or SET WRAP MODE Example 4A 32 4Ah must precede the GRAFIN2 command 20 02 X coordinate of anchor 220h 32 01 Y coordinate of anchor 132h Related Command CURSOR OFF CURSOR ON RUBBERBAND BOX 214 July 1984 GRAFIN2 User a Manual GRAFIN2 Command Dictionary SET CLIP MODE Sets clip mode for cursor tracking Environment Command Hex 22 corners Decimal 34 corners Arguments 8 bytes corners low x high x low y high y low x high x low y high y Bytes Returned None Description SET CLIP MODE turns on clip mode and defines the diagonai corners of the bounding box The coordinates of the bounding box are always screen coordinates In clip mode when you move the mouse beyond the area defined by the bounding box the cursor is clipped at the boundary The cursor will still move along the other axis as long it is within the boundary Refer to Fig ure 1 2 Example 4A 22 4Ah must precede all GRAFIN2 commands 64 00 X 64h 32 00 Y 32h 2C 01 2 12C
45. iting Customized GRAFIN2 Commands GRAFIN2 Users Manual The algorithm in C for making the upper byte is int upper_byte upper_byte 1 check all parameters for size for i number_params i gt 0 i f we have a parameter shift upper_byte up 1 upper_byte 2 now set the LSB to 1 if a word parameter if param i WORD upper_byte 1 Here is how sexec interprets the upper byte When the upper byte equals 1 there are no parameters left on the stack When the upper byte is greater than 1 the LSB of the upper byte represents the next parameter of the opcode If it is 0 the parameter is a byte if a 1 the parameter is a word The firmware then performs a right shift and tests if the upper byte is greater than 1 When the upper byte is equal to 1 there are no more parameters for that opcode on the stack Some typical upper bytes are Opcode Upper_Byte Composite Opcode 61h Draw Oih 0161h 72h Compdr Oih 0172h 52h Mov P1 07h 0752h 4Eh Mov Color 02h 024Eh 70h Pixblt OBh OB70h The byte word distinction is important Since the stack is allocated in words sexec must know which stack entries are byte parame ters which are words and which are opcodes The stack always pops words when a byte is sent the upper byte is thrown away Sexec stops when it sees a 0 opcode This 0 is preloaded at the bot tom of the stack by the GRAFINe firmware Implementing the Sketch Cursor The Sketch cursor opc
46. lor to black and clears the screen 1 10 October 1984 Chapter 2 GRAFIN2 COMMAND DICTIONARY This chapter alphabetically lists the GRAFIN2 commands Terms used in this chapter are defined in Chapter 1 The commands are summarized by function in tables in Chapter 1 The command entries in this chapter follow a standard format which includes Name and short description of the command The functional group of the command Hex opcode and arguments if any Decimal opcode and arguments if any Definition of the argument s Bytes returned if any Description of the command o Related commands ooooo0o o In the command arguments opcodes are in boldface while vari ables you must supply are in italics Be sure to precede the opcode with 4Ah to indicate a GRAFIN2 command In the examples bytes that you enter are given in boldface bytes that the computer returns are given in regular this style type July 1984 21 GRAFIN2 Command Dictionary GRAFIN2 User s Manual CROSSHAIR CURSOR Selects a crosshair cursor shape Cursor Tracking Command Hex 31 Decimal 49 Arguments None Bytes Returned None Description CROSSHAIR CURSOR selects the crosshair shape for the cursor and displays the cursor on the screen While displayed the cursor tracks the mouse The cursor is drawn in the comple mentary color of the existing pixels A crosshair cursor is the default shape of the INIT GRAFIN2 and SKETCH commands The
47. n FORTH is invoked Errors are displayed on the Omega screen When leaving FORTH the error count is displayed 52h Text mode Used to download code that may contain er rors The error count is reset to zero when FORTH is in voked All FORTH code except comments is displayed on the Omega screen When leaving FORTH the error count is displayed 53h Forget Words Used to delete all user defined commands from the dictionary See also the FORTH forget rou tine October 1984 37 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual COMMAND EXAMPLES This section contains examples that show the implementation of three cursors and some grid drawing routines Writing Custom Cursors In general you need to create three routines to draw a custom cur sor o acursor erasing routine o acursor drawing routine o an installation routine The three routines are linked by the pointer variables ccdown and ccup The installation routine puts the address of the curser erasing routine in ccdown and the address of the cursor drawing routine in ccup The routine remove uses the erasing routine pointed to by ccdown to erase the cursor In addition remove pushes the current cursor coordinates on the stack before using ccdown The routine new uses the drawing routine pointed to by ccup to draw the new cursor New pushes the current cursor coordinates on the stack before using ccup The installation routine needs to eras
48. n X X Offset X Scale x Tablet X Screen Y Y Offset Y Scale x Tablet Y The offsets move the coordinates a constant amount along each axis The offsets are each two bytes of data in 16 bit two s comple ment form X Offset Y Offset 32768 through 32767 8000h through 7FFFh The scale factor shrinks or expands the tablet coordinates to fit the screen The scale factors are each two bytes of data in 16 bit two s complement form The most significant 4 bits form a signed integer and the least significant 12 bits form the fractional part X Scale Y Scale 8 00000 through 7 99976 8000h through 7FFFh To convert a decimal scale factor to hex multiply the decimal number by 4096 convert to hex and truncate to 16 bits Table 2 1 contains some decimal scale factors and their hex equivalents July 1984 2 17 GRAFIN2 Command Dictionary GRAFIN2 User s Manual Table 2 1 Decimal and Hex Scale Factors Decimal Hex Decimal Hex 1 00000 1000 1 50000 1800 0 50000 0800 1 50000 E800 0 50000 F800 3 00000 3000 0 75000 0C00 3 00000 DOCO 0 75000 F400 7 50000 8800 Le The 0 0 point on the Omega screen is the upper left corner while on most tablets it is the lower left corner Therefore you will usu ally want to reverse the Y coordinate system so that cursor move ment on the screen is the same as the mouse You can do this by setting a negative Y Scale factor and a positive full screen Offset Tables 2 2 and 2 3 con
49. ng commands allow you to select different cursor types The cursor types are o Crosshair cursor default CROSSHAIR CURSOR SET CURSCR SIZE Rubberband box cursor RUBBERBAND BOX Rubberband line cursor RUBBERBAND LINE Sketching cursor SKETCH When you select a cursor type it becomes the currently selected cursor and is displayed on the screen The cursor remains on the screen until explicitly removed with INIT GRAFIN2 or CURSOR OFF Generally you will want to remove the cursor before drawing over its location If you draw over the cursor a shadow image of the cursor s pixels will remain on the screen The CURSOR ON command displays the currently selected cursor To change cursors enter one of the four cursor commands The cursor tracking commands are summarized in Table 1 3 The Arguments and Returns columns indicate the number of bytes if any required as input or returned as output X Y indicates coor dinates 14 October 1984 GRAFIN2 User s Manual Overview TABLE 1 3 Cursor Tracking Commands A Name a ee E Arguments Returns CROSSHAIR CURSOR 31 49 none none CURSOR OFF 3F 63 none none CURSOR ON 30 48 none none RUBBERBAND BOX 33 51 4 X Y none RUBBERBAND LINE 32 50 4 X Y none SET CURSOR SIZE 23 35 4 a none SKETCH 34 52 none none al 2 bytes each halfwidth and haifheight of the crosshair cursor in pixels Event Queue Commands The event queue stores up to 100 button events
50. ns the current button ID on the TOS This word is 0 if no buttons are pressed The button ID format is tablet dependent clip Clips the XY coordinates on the TOS so that it is within the current bounding box defined by hiXclip loXclip hiYclip and lo Yeltp cpos Pushes the current tablet coordinates on the stack X is TOS csend Gets a byte from the Omega and puts it on the stack exhair Uses the XY coordinates on the TOS to produce the appropriate Omega move and draw instructions needed to create a comple mented crosshair cursor The XY are replaced on the stack by the Omega instructions and data event Moves a button from the event queue to the stack If the event queue is empty event puts a 1 on the stack otherwise event pushes a word with the button in the low byte top of stack followed by a word of X coordinate then a word of Y coordinate The X and Y are in tablet coordinates hcoord Gets an XY coordinate from the host computer and places it on the stack The host must send four bytes low_x hi x low_y hiy The Omega must be ready to accept an opcode hget Gets a byte from the host computer fills leading zeros to 16 bits and returns that word as the TOS The Omega must be ready to accept an opcode hput Sends the low byte of the TOS to the host computer discarding the high byte The Omega must be ready to accept an opcode 320 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Comman
51. ode 34h leaves a trail behind the cursor during the time a button is pushed on the mouse Figure 3 7 illus trates the implementation of the Sketch cursor 312 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands Sketch contains two roulines inkup and U34 U34 uses the xhair_set routine instead of remove to erase the previous cursor To implement Sketch we first set hexadecimal as the current radix and define the variables zanchor and yanchor Next we create a routine inkup that draws the cursor s trail in che current Omega drawing color while a button is pressed Inkup is 1 hex set hexadecimal format for numbers 2 O var xanchor initialize our variables 3 Ovar yanchor compute cursor routine ink lines if button pressed 4 inkup 5 exhair compute the Xhair cursor 6 cpostoscreen get tablet and convert to screen coords 7 button if eet the button status if a button is pressed 8 0161 rrot push draw rotate XY to TOS 9 0753 mov P2 10 2over yanchor swap yanchor store Y in yanchor 11 Zover xanchor swap xanchor store X in xanchor 12 0752 mov P1 13 680250 set solid line 14 else 15 xanchor yanchor update last position 16 then 17 sketch in current drawing color while a button is pressed 18 U34 19 xhair_set set crosshair cursor 20 inkup ccup install new routine 21 new 23 Figure 3 7 Implementing the Sketc
52. pter on writing commands in FORTH Adds an appendix on Metheus FORTH This equipment complies with the requirements in part 15 of FCC rules for a class A computing device Operation of this equipment in a residential area may cause unacceptable interference to radio and TV reception requiring the operator to take whatever steps are necessary to correct interference October 1984 att SERVICE INFORMATION Contact the Graphics System Service Center GSSC when you need any Metheus graphics system repaired replaced or upgraded This includes both hardware and firmware products Following these simple instructions when you call or write will insure the quickest possible response to your request 1 You must provide these three items when you call or write to ihe service center Model Number Serial Number Purchase Order Number Model numbers and serial numbers are marked on the outside of the chassis packaged products on the board artwork or on the firmware The purchase order number authorizes the ser vice center to charge for services They can also provide the latest upgrade and service contract costs 2 Obtain a Return Authorization RA number from the service center BEFORE sending any equipment Use this number in all correspondence Contact the Service Center at this address Graphics System Service Center Metheus Corporation 5510 N E Elam Young Parkway Hillsboro Oregon 97123 503 640 8000 PREF
53. r The TV cursor opcode 35h is not supplied with the standard GRAFIN2 firmware The command draws a small rectangle on the screen to be the TV receiver and the cursor acts as a roving camera The command performs a block transfer of the informa tion the cursor sees to the receiver area It is helpful to have something on the Omega screen for the cursor to see when you invoke the TV cursor The TV cursor defines two routines bltup and U35 But first we set the current radix to hex and define two variables vsave and ysave The bltup routine performs a block transfer of the information 314 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands 1 hex set hexadecimal format for numbers 2 O var xsave define our variables 3 0 var ysave routine to compute the cursor drawing commands 4 bltup 5 over over copy the XY 6 xsave ysave save the X Y away for now 7 cxhair compute the cross hair 8 0 80 80 0B70 data for the pixblt 9 1FF dup 0783 mov P2 pixbit destination 10 ysave xsave 0752 mov P1 pixblt source 11 install this as a new cursor name it U35 12 U35 13 remove remove a cursor if visible 14 bltup ccup install cursor draw routine 15 exhair ccdown install cursor erase routine 16 0163 draw rectangle around destination 17 OFF 024E set color 255 white 18 1FE dup 0752 mov P1 19 280 dup 0753
54. rogram completely crashes you can regain control by turning the Omega off and back on Be sure to turn switch 7 ON when you are coii playing with FORTH otherwise the Omega will not boot up CAUTION Be sure to replace the cover of the Omega after setting the switch or you may damage the circuit board The Omega s cooling system requires the cover to be in place 3 6 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands METHOD TWO DOWNLOADING You can download routines to the FORTH interpreter with the GRAFIN firmware User defined routines execute before the rou tines located in the firmware Therefore if you write a new version of an existing command your command executes instead of the original The original is not affected Entering opcodes 50h 51h or 52h performs three functions removes the cursor if it was visible sets the cursor type to crosshair and opens a channel to the host FORTH input is ter minated by an escape 1Bh Opcode 53h Forget Words is used to delete all user defined entries from the FORTH dictionary You can Table 3 2 summarizes the GRAFIN2 commands that call FORTH TABLE 3 2 GRAFIN2 FORTH COMMANDS Opcode Meaning 50h Comm mode Used to download debugged code The er ror count is reset to zero when FORTH is invoked Noth ing is displayed on the Omega screen 51ih Error mode Used to download code that may contain errors The error count is reset to zero whe
55. ser s Manua GRAFIN2 COMMANDS GRAFIN2 commands fall into three categories o Environment commands o Cursor Tracking commands o Event Queue commands Environment commands initialize the system inquire the version number and inquire the error status The last section of this chapter discusses the default initialization conditions and how tc change them Cursor Tracking commands allow you to select a style of cursor and to control when it appears on the screen When the cursor is displayed it tracks the mouse Event Queue commands keep track of button events so that button input is sent to the host in an orderly manner Table 1 1 lists the GRAFIN2 commands Following the table cach category of commands is discussed separately TABLE 1 1 GRAFIN2 Commands Environment Cursor Tracking Event Queue INIT GRAFIN2 CROSSHAIR CURSOR EVENT COUNT INQUIRE ERROR CURSOR OFF FLUSH Q INQUIRE VERSION CURSOR ON READ CURRENT POSITION SET CLIP MODE RUBBERBAND BOX READ Q SET OFFSET SCALE RUBBERBAND LINE READ Q AND WAIT SET SCREEN SIZE SET CURSOR SIZE SET Q MODE SET TABLET SIZE SKETCH SET WRAP MODE WRITE TABLE NOTE Every GRAFIN2 opcode must begin with these two bytes the first is 4Ah 74 decimal and the second is the specific com mand opcode 14 October 1934 GRAFIN2 User s Manual Overview Environment Commands The environment commands allow you to o Map the tablet to the screen INIT GRAFIN2 SET OFFSET S
56. sor routine exhair Because of this we install exhair as the cursor erasing routine Next in line 16 we draw a box around the TV receiver Since the stack is unloaded in reverse order the first thing we push is the Omega RECT instruction outline box We then set the drawing color to white color 255 Next we push coordinates for the two corners of the box with the appropriate MOV P1 and MOV P2 instructions in lines 18 and 19 One corner is at 1FEh 1FEh and the other is at 280h 280h Finally we call ne in line 20 to draw the cursor the first time New will call bltup to draw the cursor Before the next cursor is drawn the previous cursor must be removed Since the routine exhair was installed as the erase rou tine the GRAFIN2 firmware will automatically invoke cxhair after bitup so that the crosshair cursor erase instructions and data are on the TOS Thus the previous cursor is erased before the next one is drawn since the stack is unloaded top to bottom Implementing Grid and Grid Drawing Routines The final command example shown in Figure 3 9 contains three grid routines U18 Followed by one byte each of X spacing and Y spacing to set grid size The cursor is snapped to the grid U19 Turns off snapping the cursor to the grid 316 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands U81 Followed by one byte each of X spacing and Y spacing to set grid size Draws a grid on the screen in t
57. st xanchor 6 wgethost yanchor 7 routine to push the complement vector data to the stack 8 rlcomp begin definition of rubberline compute 9 0172 push compdr 10 rrot get X to TOS then Y 11 0752 push mov P1 flag 12 yanchor xanchor get the anchor points 13 0753 push mov P2 flag 14 68 0250 sets a solid line Th end definition of rleomp rubber line cursor 16 U32 17 remove 18 rlcomp dup ccdown ccup install new routine 19 anchor 20 new SLL Figure 3 6 Implementing the Rubberband Line Cursor position on the stack Since we are pushing Omega instructions on the stack the first actions are the last items pushed on the stack For rleomp the last action is the complement draw Thus the first Omega opcode that we push is the COMPDR instruction in line 9 After pushing the COMPDR opcode we move the XY on top of it 3 10 October 1984 GRAFIN2 Users Manual Writing Customized GRAFIN2 Commands using the RROT command RROT rotates the top three stack entries so that nl becomes n3 If the stack contained abc it now contains cab This leaves X on top of the stack with Y beneath it Next we push the MOV P1 opcode 0752h to the stack its parame ters are the X and Y already on the stack In line 12 we retrieve the anchor points from yanchor and zanchor the X coordinate will be on top then push the MOV P2 instruction in line 13 Finally we push
58. tain the scale and offset values in hex and decimal to map a 2200 by 2200 Summagraphics tablet to the 0300 0400 and 500 Kee eg Table 2 2 Tablet To Screen Conversions Hexadecimal Screen Size xX Offset xX Scale YOffset Y Scale 1024 by 768 0000 0072 OH FA6C 736 by 552 0000 055A O27 F6FF 1280 by 1024 0000 094E OFF F890 640 by 512 0000 04A7 OFF FC49 GE Table 2 3 Tablet To Screen Conversions Decimal Screen Size xX Offset X Scale Y Offset Y Scale 1024 by 768 0000 1906 767 1424 736 by 552 0000 1370 511 1025 1280 by 1024 0000 2382 1023 1904 640 by 512 0000 1191 oil 951 2 18 July 1984 GRAFIN User s Manual GRAFIN2 Command Dictionary Example To map a 2200 by 2200 tablet to a 736 by 552 screen 4A 20 4Ah must precede all GRAFIN2 commands 00 00 X Offset 0000h 5A 05 X Scale 055Ah 27 02 Y Offset 0227h FF F6 Y Scale F6FFh Related Commands INIT GRAFIN2 SET SCREEN SIZE SET TABLET SIZE October 1984 2 19 GRAFIN2 Command Dictionary GRAFIN2 User s Manual SET Q MODE Sets button detect and data reporting modes Fvent Queue Command Hex 41 detect byte report byte Decimal 65 detect byte report byte Arguments 2 bytes detect byte type of button edge that con stitutes an event report byte whether tablet or screen coordi nates are reported to the host Bytes Returned None Description SET Q MODE determines which button edge s are detected and selects whether coordin
59. the Omega PATTERN instruction and data in line 14 to seta solid line The routine U32 installs the rubber line cursor In line 17 it calls remove to erase any currently drawn cursor In line 18 it gets the address of rlcomp to the stack duplicates it then saves it in ccup and ccdown It then calls anchor in line 19 to get the XY coordi nates of the anchor location from the host computer Finally it calls new in line 20 to draw the new cursor Once the stack contains the instructions and data the routines sexec new and remove are automatically invoked at the 60Hz refresh rate After this the routine rleomp is called automatically whenever the system needs to update the cursor position Stack Management With SEXEC Since the stack uses 16 bit numbers the upper byte of each Omega opcode on the stack tells sexec the location and size of the opcode s parameters Note that only the low byte of the opcode is sent to the Omega The upper byte is used for stack management If the upper byte is 0 the next word on the stack points to a block of data to be sent to the Omega The first word of the block is the byte count 16 bits and the following bytes are data If the upper byte is non zero the parameters for the opcode are on the stack The upper byte specifies how many parameters are on the stack which of them are bytes and which of them are words Only seven parameters can be passed in this manner October 1984 3 11 Wr
60. theus FORTH Table C 1 Looping and Conditional Primitives Structure BEGIN AGAIN BEGIN flag UNTIL BEGIN flag WHILE REPEAT IF THEN IF ELSE THEN DO LOOP DO ent LOOP CDO CLOOP CDO ent C LOOP DO LEAVE LOOP CDO CLEAVE CLOOP October 1984 Description Infinite loop Loop until flag on stack is true Exit loop when flag is false If TOS is true execute inner code If TOS is true execute IF code other wise ELSE code Iteration loop uses words for counters Ditto increment by ent Iteration loop uses bytes for counters Ditto increment by cnt Do loop but LEAVE forces exit CDO loop but CLEAVE forces exit Metheus FORTH GRAFIN2 User s Manual Name MOD 1 2 1 2 Qe 2 ABS AND Di INTEGER IOR LSHIFT MAX MIN MOD NEGATE RSHIFT XOR CA Table C 2 Arithmetic and Logical Words Function Signed multiply n2 by n1 return 16 bit word on stack 16 bit add n1 and n2 replace both with 16 bit result on stack 16 bit subtract n2 from ni replace both with 16 bit result on stack X Divide pn by n2 replace with 16 bit result on stack Given n1 n2 and n3 on the stack perform n2 n3 n1 and leave the 16 bit result on the stack Divide n2 by n1 Replace both by a 16 bit quotient as n2 and a 16 bit remainder as TOS Increment TOS by 1 Increment TOS by 2 Decrement TOS by 1 Decrement TOS b
61. to reset values used in tablet to screen transformations and screen clipping The TOS is the screen width the word beneath it is the screen height October 1984 3 21 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manual Size_init sets these variables yoffset twidth xoffset theight yscale hiXclip xscale loXclip swidth hiYclip sheight lo Yclip toscreen Converts the XY coordinates on the TOS from tablet coordi nates to screen coordinates using the current offsets and scales After conversion a user defined filter can be applied by the routine pointed to by uscaleat Finally the position is clipped or wrapped by invoking the routine whose address is in clpwrp weethost Gets a word from the host computer and puts it on the stack The Omega must be ready to accept an opcode If the host does not send a word the Omega will hang and need to be reset C wputhost Sends the word on the TOS to the host computer The Omega must be ready to accept an opcode wrap Wraps the XY coordinates on the TOS so that the point is within the current bounding box defined by hiXclip loXclip hiYclip and lo Yclip wsend Sends the top word on the stack to the Omega xfinit Uses the variables swidth and tundth to calculate xscale and xoffset and sheight and thetght to calculate yoffset and yscale The scale and offset values are used to convert tablet to screen coordinates so that the full tablet size is mapped to the full screen
62. umma Mouse Bit Pad One 1 L Data Format GTCO DIGI PAD5 F 0081 S Figure 1 1 Button ID Formats The origin 0 0 point on the Omega screen is the upper left corner while on most tablets it is the lower left corner Several commands map the tablet to the screen and adjust the coordinate systems A default mapping is performed by the INIT GRAFIN2 command Coordinates can be reported to or from the host as either tablet coordinates or screen coordinates Coordinates are given in the format X Y Each coordinate is two bytes low x high x lew y high y The borders of the mapped area on the screen form a bounding box This is usually the edge of the screen but you can also specify a different bounding box with the SET CLIP MODE and Si WRAP MODE commands The coordinates of the corners of the bounding box are always given in screen coordinates When the mouse reaches the edge of the area mapped to the 1 2 October 1954 GRAFIN2 User s Manual Overview bounding box the cursor either clips or wraps Figure i 2 itus trates the behavior of the cursor in clip and wrap modes In ciip mode the cursor always remains within the bounding box In wrap mode when the mouse moves beyond the mapped area the cursor reappears on the opposite side of the bounding box _ Area Corresponding to Bounding Box Bounding Box Clip Mode Wrap Mode F 0078 Figure 1 2 Clip Mode and Wrap Mode October 1984 1 5 Overview GRAFIN2 U
63. ursor 0 ccccesceeeeeeeetnteeetneeees 3 14 Implementing Grid and Grid Drawing Routines 2 3 16 GRAFIN2 Subroutines Variables and Pointers sncccenee 3 19 GRAFIN2 Subroutines 0 ce ete e eninene ernie eneeneee 3 19 Scalar Variables xcs 0c scraided gence head A IRI ERA ENSCH 3 23 Pointer Variables aieri socors ta bids triyo cs aint Eienenn 3 24 APPENDIX A GRAFIN2 INSTALLATION APPENDIX B GRAFIN AND GRAFIN2 DIFFERENCES APPENDIX C METHEUS FORTH Syntax Changes eessen deeg ett ee EEN C 1 General Purpose Additions cc ccceeeceteneceeceeeeseesaeeeseeeneas C 2 Summary EE C 3 Dele tionisis egent eben aduvahersaeai Ed bsdsun beac adeno C 10 x October 1984 Contents GRAFINE Users Manuel FIGURES Fei Button ID Formats NERVEN ened AE R G 1 2 1 2 Clip Mode and Wrap Mode E 1 3 1 3 Sample of GRAFIN2 Commande e Le 10 3 1 Typical Stack Usage EEN EEN EEN 3 3 3 2 Sum Subroutine 0 coda atthe ee 3 4 3 3 Executing the Sum7 Routine 0c eeeeeeeeees 3 4 3 4 Implementing the Minmax Routine seere 3 5 3 5 An Installation Routine 0 cc eee tnenee ese eeneereenereees 3 8 36 Implementing the Rubberband Line Cursor errre 3 10 3 7 Implementing the Sketch Cursor AE 3 13 3 8 Implementing the TV Cursor ceteris 3 15 3 9 Implementing Grid Drawing Routines eee Gtia 3 18 A 1 Position of the Interface and GRAFIN2 Boards
64. utes the stack contains the Omega instructions placed on it by the routines The instructions on the stack are executed unloaded by the sexee Stack EXECu tion routine The GRAFIN2 firmware automatically calls new remove and sexec at the 60Hz refresh rate until it receives another command Implementing the Rubberband Line Cursor The Rubberband Line cursor is supplied in the GRAFIN2 firmware The Rubberband Line cursor draws a complement vector between an anchor point and the cursor s location Figure 3 6 shows the implementation of the Rubberband Line cursor The Rubberband Line command contains three subroutines anchor rlcomp and U32 Before defining the subroutines we set hex as the radix and define two variables zanchor and yanchor These variables hold the location of the anchor point for the com plement vector The routine anchor in line 4 reads an XY coordi nate from the host and saves it in zanchor and yanchor Line 8 begins the definition of the rleomp Rubber Line COMPute routine Rlcomp pushes the data and opcodes needed to draw a complement mode vector from the anchor location to the current tablet position Rlcomp is entered with the current XY cursor October 1984 3 9 Writing Customized GRAFIN2 Commands GRAFIN2 Users Manua 1 hex set hexadecimal format for numbers 2 Ovar xanchor define anchor points 3 0 var yanchor 4 anchor routine to set anchor point from host data 5 wgetho
65. with SET TA BLET SIZE If you need to change both tablet and screen sizes is sue both commands The bounding box for clip or wrap mode is set to the full screen SET SCREEN SIZE does not change the default values used by INIT GRAFIN2 Example 4A 11 4A must precede all GRAFIN2 commands 00 05 screenwidth 1280 500h 00 04 screenheight 1024 400h Related Commands INIT GRAFIN2 SET OFFSET SCALE SET TABLET SIZE 2 22 October 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary SET TABLET SIZE Sets tablet size for mapping Environment Command Hex 12 tabletwidth tabletheight Arguments 4 bytes tablefwidth low width high width ta bletheight low height high height Bytes Returned None Description SET TABLET SIZE maps the tablet size specified in the arguments to the default screen size The default screen size is 1024 by 768 pixels The screen size can be changed with SET SCREEN SIZE If you need to change both tablet and screen sizes issue both commands SET TABLET SIZE does not change the default values used by INIT GRAFIN2 Example 4A 12 4A must precede all GRAFIN2 commands 00 04 tabletwidth 1024 400h 00 04 tabletheight 1024 400h Related Commands INIT GRAFIN2 SET OFFSET SCALE SET SCREEN SIZE October 1984 223 GRAFIN2 Command Dictionary GRAFIN2 User s Manual SET WRAP MODE Sets wrap around mode for cursor tracking Environment Command He
66. x 21 corners Arguments 8 bytes corners low x high x low y high y low X high x low yp high y Bytes Returned None Description SET WRAP MODE turns on wrap mode and defines the diagonal corners of the bounding box The coordinates of the bounding box are always screen coordinates If you move the mouse beyond the area defined by the bounding box the cursor wraps around the boundary and reappears on the opposite side of the bounding box Refer to Figure 1 2 Example 4A 22 4Ah must precede all GRAFIN2 commands 64 00 X 64h 32 00 Y 32h SC 01 X 12Ch CH 00 Y gt C8h Related Command SET CLIP MODE 2 24 October 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary SKETCH Turns on sketching mode Cursor Tracking Command Hex 34 Decimal mal 52 Arguments None Bytes Returned None Description SKETCH is used to make freeform drawings ou the screen SKETCH draws in the currently selected Omega color while any button is held down on the mouse Use the Omega SETCOL command to change color while drawing SKETCH uses the crosshair cursor While displayed the cursor tracks the mouse The cursor remains on the screen until removed by INIT GRAFIN2 or CURSOR OFF Button events are entered in the event queue as defined by the SET Q MODE command Related Commands CURSOR OFF CURSOR ON SET CURSOR SIZE SET Q MODE October 1984 220 GRAFIN2 Command Dictionary GRAFIN2 User s Manu
67. y 2 Multiply TOS by 2 Divide TOS by 2 Absolute value of TOS Bit AND Signed multiply n2 by TOS Replaces both with a 32 bit signed number the 16 LSBs in TOS Convert from 32 bit fixed point to integer n2 contains the 16 MSBs the TOS is the 16 LSBs The 32 bit number is divided by 4096 and a 16 bit number is returned Bit inclusive OR Arithmetic left shift of n2 by the number of bits specified in the TOS word Compare ni and nz larger value becomes TOS Compare n1 and n2 smaller value becomes TOS Signed divide n2 by the low byte of the TOS Replace both words by the 8 bit remainder expanded to 16 bits 2 s complement the TOS word Arithmetic right shift n2 by the number of bits specified in the TOS word Bit exclusive OR October 1984 GRAFIN2 User s Manual Metheus FORTH Name LOOP AGAIN BEGIN CASE CEND CLOOP DO ELSE IF LEAVE LOOP REPEAT THEN UNTIL WHILE Table C 3 Compiler Directives Function Terminate a DO loop The number on TOS is added to the current iteration count If the result is gt the final value stop End token for a BEGIN AGAIN infinite loop Start of a BEGIN loop Start of CASE statement The word on TOS indexes into the case statement Each word in the case statement must be exactly 1 word no literals allowed End of CASE statement Terminate a CDO loop The low byte on TOS is added to the current iteration count If the result is gt t
68. y GRAFIN2 User s Manual READ CURRENT POSITION Reports the position of the mouse Fvent Queue Command Hex 44 Decimal 68 Arguments None Bytes Returned 4 bytes low x high x low y high y Description READ CURRENT POSITION reads and reports the current location of the mouse in either tablet or screen coordi nates The SET Q MODE command determines whether the iocation of the mouse is reported in tablet or screen coordinates READ CURRENT POSITION does not affect the event queue Related Commands SET Q MODE 2 10 July 1984 GRAFIN2 User s Manual GRAFIN2 Command Dictionary READ Q Reads next entry from the button event quew Event Queue Command Arguments None Bytes Returned 6 bytes button ID reserved byte low x high x low y high y Description READ Q reads the next entry from the button event queue and removes the entry from the queue Fvents are read in first in first out order READ Q returns the button ID a byte reserved for future use and the coordinates when the button was hit READ Q reports either tablet or screen coordinates depending on the setting of the SET Q MODE command When the queue is empty the button ID is 00 and the current X and Y coordinates are returned as in READ CURRENT POSITION Example 4A 42 4Ah must precede all GRAFIN2 commands 02 00 button 2 was hit reserved byte 2C 01 X coordinate 12Ch C8 00 Y coordinate C8h Related Commands READ CURRENT POSITION

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