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27-11-88/T\MOU01
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » CEEFAX disks » telesoftware11.adl |
| Filename: | 27-11-88/T\MOU01 |
| Read OK: | ✔ |
| File size: | 2C1B bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
File contents
Using a mouse with the BBC microcomputer - by - Gordon Horsington
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Module 1. Reading the mouse coordinates
---------------------------------------
The X and Y coordinates assigned to the position of a mouse can be quite
arbitrary. The range of coordinates you choose to make available and the
rate at which they change with mouse movement is entirely under software
control. If, for example, you want to use a mouse to draw on a graphics
screen it would be a good idea to use a range of coordinates from 0 to
1279 for X and 0 to 1023 for Y, with increments of 4 for each interrupt
generated by the mouse.
The movement of the mouse ball can generate an interrupt using either CB1
or CB2. An interrupt generated by CB1 indicates a movement either left or
right and an interrupt generated by CB2 indicates a movement either up or
down. The plane of the change (either X or Y) is indicated by the
handshake lines but the direction (either increasing or decreasing) is
indicated by two bits in data register B (DRB, &FE60). If an interrupt is
generated by CB1 then your program should examine bit 0 of DRB. If bit 0
of DRB is set X is decreasing, if it is clear X is increasing. Similarly
if an interrupt is generated by CB2 then your program should examine bit 2
of DRB. If bit 2 of DRB is set Y is decreasing, if it is clear Y is
increasing.
It is possible to latch the data in DRB so that the values read from the
register are those that were present when a change of signal occured on
CB1. This means that, if latching is selected, the data for movement in
the X direction will remain available until a new movement is detected.
This would be very useful if it was also available for movement in the Y
direction, but latching is not available for signals on CB2. It is only
worth selecting the latching mode (by setting bit 1 of the ACR at &FE6B)
if you are only interested in movement from side to side. In practice this
could be useful with games software.
Because latching is unavailable for movements in the Y plane the mouse
generated interrupts have to be intercepted at the high priority IRQ1V
interrupt vector to ensure that bits 0 and 2 of DRB reflect the true
change of direction in the X and Y coordinates. If the interrupts are
intercepted at the low priority IRQ2V interrupt vector then the
non-latched DRB may or may not reflect the direction of the mouse
movement. In the demonstration programs which revector an interrupt
vector, IRQ1V is used and VIA-B is in the non-latched mode.
The program MOUSE illustrates how the IRQ1V vector is revectored to point
to the new code labeled interrupt. Data register B is selected as an input
by storing zero in data direction register B. CB1 and CB2 interrupts are
enabled by storing &98 (%10011000) in the interrupt enable register, both
CB1 and CB2 produce an interrupt on a positive transition, and the
interrupt is cleared by selecting (reading from) the data register B. In
this example the initial coordinates assigned to the current mouse
position are 0,0. The initial coordinates could be anything you like
within the range from 0 to 255.
All the example programs in this series use a range of from 0 to 255 for
both the X and Y coordinates. This simplifies the demonstration programs
because only one byte is used to store each coordinate. The X and Y
coordinates can then be read with the BASIC ? indirection operator. If you
decide to modify any of the demonstration programs to use a larger range
of coordinates it is a good idea to use four bytes for each coordinate
even if you only intend to use two of the four bytes to store the actual
number. Using four bytes will allow BASIC to read the coordinate with the
! indirection operator. If only two bytes are used then the ? indirection
operator will need to be used twice for each coordinate. You might also
like to consider storing the coordinates in the memory allocated to the
system integer variables (A% to Z%) and this will simplify reading the
coordinates even further.
The interrupt handling routine in MOUSE does not use either the X or Y
registers and so only the accumulator (from &FC) is stored on the stack at
the beginning of the routine and restored at the end. The interrupt
handling routine first examines bit 7 of the interrupt flag register. Bit
7 will always be set for a User Port interrupt. If a mouse connected to
the User Port is the source of an interrupt then either bit 3 or bit 4 of
the IFR will also be set. Bit 3 will be set for an interrupt generated by
CB2 and bit 4 will be set for an interrupt generated by CB1. If either bit
4 or bit 3 of the IFR is set then the direction of the movement is found
by examining either bit 0 or bit 2 of the DRB. If the direction is
increasing the the appropriate coordinate is incremented by 1 and if it is
decreasing then the appropriate coordinate is decremented by 1.
This demonstration program must run in the I/O processor and it uses the
most simple form of polling the mouse buttons from BASIC. The mouse
coordinates are peeked from the zero page memory locations and displayed
in an endless loop. Chain the program and move the mouse around to see the
range and sensitivity of the movement. To stop the program press either
the Escape key or the Break key. In module 2 I will show how the program
MOUSE can be modified to make it Tube compatible.
10 REM> MOUSE
20 DIM mcode &200 :REM: machine code at mcode
30 xcoord=&80 :REM: x coordinate, range 0-255
40 ycoord=&81 :REM: y coordinate, range 0-255
50 savereg=&FC :REM: interrupt accumulator save register
60 irq1v=&204 :REM: primary interrupt vector
70 drb=&FE60 :REM: data register B
80 ddrb=&FE62 :REM: data direction register B
90 pcr=&FE6C :REM: peripheral control register
100 ifr=&FE6D :REM: interrupt flag register
110 ier=&FE6E :REM: interrupt enable register
120 FOR pass=0 TO 2 STEP 2
130 P%=mcode
140 [ OPT pass
150 LDX irq1v \ current primary interrupt vector, low byte
160 LDY irq1v+1 \ current primary interrupt vector, high byte
170 CPY #interrupt DIV 256 \ compare high byte
180 BEQ disable \ restore old vector if altered
190 STX oldirq1v \ save original irq1 vector, low byte
200 STY oldirq1v+1 \ save original irq1 vector, high byte
210 LDX #interrupt MOD 256 \ new irq1 vector, low byte
220 LDY #interrupt DIV 256 \ new irq1 vector, high byte
230 SEI \ set interrupt disable flag
240 STX irq1v \ alter irq1 vector, low byte
250 STY irq1v+1 \ alter irq1 vector, high byte
260 CLI \ clear interrupt disable flag
270 LDA #&98 \ %10011000, ie. enable CB1/2
280 STA ier \ interrupt enable register
290 LDA pcr \ peripheral control register
300 AND #&0F \ AND with %00001111, ie clear bits 4-7
310 ORA #&50 \ OR with %01010000, ie. set bits 4 and 6
320 STA pcr \ interrupt on +ve transition, CB2 input,
\ DRB to clear
330 LDA #&00 \ user port input
340 STA ddrb \ data direction register B
350 STA xcoord \ initial value for x coordinate
360 STA ycoord \ initial value for y coordinate
370 RTS \ return to BASIC
380 .disable
390 LDA #&18 \ %00011000, ready to clear bits 3 and 4 of ier
400 LDX oldirq1v \ original irq1 vector, low byte
410 LDY oldirq1v+1 \ original irq1 vector, high byte
420 SEI \ set interrupt disable flag
430 STA ier \ interrupt enable register
440 LDA pcr \ peripheral control register
450 AND #&0F \ clear bits 4-7
460 STA pcr \ peripheral control register
470 STX irq1v \ restore the original irq1 vector, low byte
480 STY irq1v+1 \ restore the original irq1 vector, high byte
490 CLI \ clear interrupt disable flag
500 RTS \ return to BASIC
510 .interrupt
520 LDA savereg \ interrupt accumulator save register
530 PHA \ and push it on the stack
540 LDA ifr \ interrupt flag register
550 BPL notuser \ bit 7 is set if VIA-B interrupt
560 AND #&18 \ AND with %00011000, ie. test bits 3 and 4
570 BEQ notuser \ exit if not CB1 or CB2
580 AND #&10 \ AND with %00010000, ie. test CB1
590 BNE xpulse \ bit 4 set for an X direction movement
600 LDA drb \ Y direction, load data register B
610 AND #&04 \ AND with %00000100, ie. test bit 2
620 BNE ydown \ if bit 2 is set then Y is going down
630 INC ycoord \ Y is going up so increment Y coordinate
640 BNE exit \ branch if in the range 1 to 255
650 BEQ decy \ if zero then alter to 255
660 .ydown
670 LDA ycoord \ load Y coordinate
680 BEQ exit \ branch if zero because it can't go any lower
690 .decy
700 DEC ycoord \ reduce Y coordinate by 1
710 JMP exit \ restore interrupt accumulator save
\ register and RTI
720 .xpulse
730 LDA drb \ data register B
740 ROR A \ bit 0 into carry
750 BCS xdown \ X is going down if bit 0 is set
760 INC xcoord \ X is going up if bit 0 is clear
770 BNE exit \ exit if X coordinate is in the range
\ from 1 to 255
780 BEQ decx \ if X coordinate = 0 then make it 255
790 .xdown
800 LDA xcoord \ load X coordinate
810 BEQ exit \ if it is zero it can't go any lower
820 .decx
830 DEC xcoord \ decrease X coordinate by 1
840 .exit
850 PLA \ pull interrupt accumulator save
\ register off the stack
860 STA savereg \ and restore zero page
870 RTI \ return from interrupt
880 .notuser
890 PLA \ pull the interrupt accumulator save
\ register off the stack
900 STA savereg \ restore the zero page address
910 JMP (oldirq1v) \ exit via the original vector
920 .oldirq1v
930 EQUW &00 \ original irq1v
940 .lastbyte
950 ]
960 NEXT
970 CALL mcode
980 MODE7
990 mouse$=CHR$141+CHR$132+CHR$157+CHR$131+
"Mouse coordinates, range &00-&FF "+CHR$156
1000 PRINTTAB(0,1)mouse$
1010 PRINTTAB(0,2)mouse$
1020 VDU23,1,0;0;0;0;
1030 ONERROR GOTO 1120
1040 PRINTTAB(10,7)"Bytes used = &";~lastbyte-mcode
1050 REPEAT
1060 PRINTTAB(10,12)"X = &";~?&80;" "TAB(20,12);"Y = &";~?&81;" "
1070 button=?drb :REM: data register B
1080 IF (button AND &80)=0 PRINTTAB(22,17)"Right"
ELSE PRINTTAB(22,17)" "
1090 IF (button AND &40)=0 PRINTTAB(15,17)"Centre"
ELSE PRINTTAB(15,17)" "
1100 IF (button AND &20)=0 PRINTTAB(10,17)"Left"
ELSE PRINTTAB(10,17)" "
1110 UNTIL FALSE
1120 VDU23,1,1;0;0;0;
1130 CALL mcode
00000000 55 73 69 6e 67 20 61 20 6d 6f 75 73 65 20 77 69 |Using a mouse wi| 00000010 74 68 20 74 68 65 20 42 42 43 20 6d 69 63 72 6f |th the BBC micro| 00000020 63 6f 6d 70 75 74 65 72 20 2d 20 62 79 20 2d 20 |computer - by - | 00000030 47 6f 72 64 6f 6e 20 48 6f 72 73 69 6e 67 74 6f |Gordon Horsingto| 00000040 6e 0d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |n.--------------| 00000050 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------| * 00000080 2d 2d 2d 0d 0d 4d 6f 64 75 6c 65 20 31 2e 20 52 |---..Module 1. R| 00000090 65 61 64 69 6e 67 20 74 68 65 20 6d 6f 75 73 65 |eading the mouse| 000000a0 20 63 6f 6f 72 64 69 6e 61 74 65 73 20 0d 2d 2d | coordinates .--| 000000b0 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------| * 000000d0 2d 2d 2d 2d 2d 0d 0d 54 68 65 20 58 20 61 6e 64 |-----..The X and| 000000e0 20 59 20 63 6f 6f 72 64 69 6e 61 74 65 73 20 61 | Y coordinates a| 000000f0 73 73 69 67 6e 65 64 20 74 6f 20 74 68 65 20 70 |ssigned to the p| 00000100 6f 73 69 74 69 6f 6e 20 6f 66 20 61 20 6d 6f 75 |osition of a mou| 00000110 73 65 20 63 61 6e 20 62 65 20 71 75 69 74 65 0d |se can be quite.| 00000120 61 72 62 69 74 72 61 72 79 2e 20 54 68 65 20 72 |arbitrary. The r| 00000130 61 6e 67 65 20 6f 66 20 63 6f 6f 72 64 69 6e 61 |ange of coordina| 00000140 74 65 73 20 79 6f 75 20 63 68 6f 6f 73 65 20 74 |tes you choose t| 00000150 6f 20 6d 61 6b 65 20 61 76 61 69 6c 61 62 6c 65 |o make available| 00000160 20 61 6e 64 20 74 68 65 0d 72 61 74 65 20 61 74 | and the.rate at| 00000170 20 77 68 69 63 68 20 74 68 65 79 20 63 68 61 6e | which they chan| 00000180 67 65 20 77 69 74 68 20 6d 6f 75 73 65 20 6d 6f |ge with mouse mo| 00000190 76 65 6d 65 6e 74 20 69 73 20 65 6e 74 69 72 65 |vement is entire| 000001a0 6c 79 20 75 6e 64 65 72 20 73 6f 66 74 77 61 72 |ly under softwar| 000001b0 65 0d 63 6f 6e 74 72 6f 6c 2e 20 49 66 2c 20 66 |e.control. If, f| 000001c0 6f 72 20 65 78 61 6d 70 6c 65 2c 20 79 6f 75 20 |or example, you | 000001d0 77 61 6e 74 20 74 6f 20 75 73 65 20 61 20 6d 6f |want to use a mo| 000001e0 75 73 65 20 74 6f 20 64 72 61 77 20 6f 6e 20 61 |use to draw on a| 000001f0 20 67 72 61 70 68 69 63 73 0d 73 63 72 65 65 6e | graphics.screen| 00000200 20 69 74 20 77 6f 75 6c 64 20 62 65 20 61 20 67 | it would be a g| 00000210 6f 6f 64 20 69 64 65 61 20 74 6f 20 75 73 65 20 |ood idea to use | 00000220 61 20 72 61 6e 67 65 20 6f 66 20 63 6f 6f 72 64 |a range of coord| 00000230 69 6e 61 74 65 73 20 66 72 6f 6d 20 30 20 74 6f |inates from 0 to| 00000240 0d 31 32 37 39 20 66 6f 72 20 58 20 61 6e 64 20 |.1279 for X and | 00000250 30 20 74 6f 20 31 30 32 33 20 66 6f 72 20 59 2c |0 to 1023 for Y,| 00000260 20 77 69 74 68 20 69 6e 63 72 65 6d 65 6e 74 73 | with increments| 00000270 20 6f 66 20 34 20 66 6f 72 20 65 61 63 68 20 69 | of 4 for each i| 00000280 6e 74 65 72 72 75 70 74 0d 67 65 6e 65 72 61 74 |nterrupt.generat| 00000290 65 64 20 62 79 20 74 68 65 20 6d 6f 75 73 65 2e |ed by the mouse.| 000002a0 0d 0d 54 68 65 20 6d 6f 76 65 6d 65 6e 74 20 6f |..The movement o| 000002b0 66 20 74 68 65 20 6d 6f 75 73 65 20 62 61 6c 6c |f the mouse ball| 000002c0 20 63 61 6e 20 67 65 6e 65 72 61 74 65 20 61 6e | can generate an| 000002d0 20 69 6e 74 65 72 72 75 70 74 20 75 73 69 6e 67 | interrupt using| 000002e0 20 65 69 74 68 65 72 20 43 42 31 0d 6f 72 20 43 | either CB1.or C| 000002f0 42 32 2e 20 41 6e 20 69 6e 74 65 72 72 75 70 74 |B2. An interrupt| 00000300 20 67 65 6e 65 72 61 74 65 64 20 62 79 20 43 42 | generated by CB| 00000310 31 20 69 6e 64 69 63 61 74 65 73 20 61 20 6d 6f |1 indicates a mo| 00000320 76 65 6d 65 6e 74 20 65 69 74 68 65 72 20 6c 65 |vement either le| 00000330 66 74 20 6f 72 0d 72 69 67 68 74 20 61 6e 64 20 |ft or.right and | 00000340 61 6e 20 69 6e 74 65 72 72 75 70 74 20 67 65 6e |an interrupt gen| 00000350 65 72 61 74 65 64 20 62 79 20 43 42 32 20 69 6e |erated by CB2 in| 00000360 64 69 63 61 74 65 73 20 61 20 6d 6f 76 65 6d 65 |dicates a moveme| 00000370 6e 74 20 65 69 74 68 65 72 20 75 70 20 6f 72 0d |nt either up or.| 00000380 64 6f 77 6e 2e 20 54 68 65 20 70 6c 61 6e 65 20 |down. The plane | 00000390 6f 66 20 74 68 65 20 63 68 61 6e 67 65 20 28 65 |of the change (e| 000003a0 69 74 68 65 72 20 58 20 6f 72 20 59 29 20 69 73 |ither X or Y) is| 000003b0 20 69 6e 64 69 63 61 74 65 64 20 62 79 20 74 68 | indicated by th| 000003c0 65 0d 68 61 6e 64 73 68 61 6b 65 20 6c 69 6e 65 |e.handshake line| 000003d0 73 20 62 75 74 20 74 68 65 20 64 69 72 65 63 74 |s but the direct| 000003e0 69 6f 6e 20 28 65 69 74 68 65 72 20 69 6e 63 72 |ion (either incr| 000003f0 65 61 73 69 6e 67 20 6f 72 20 64 65 63 72 65 61 |easing or decrea| 00000400 73 69 6e 67 29 20 69 73 0d 69 6e 64 69 63 61 74 |sing) is.indicat| 00000410 65 64 20 62 79 20 74 77 6f 20 62 69 74 73 20 69 |ed by two bits i| 00000420 6e 20 64 61 74 61 20 72 65 67 69 73 74 65 72 20 |n data register | 00000430 42 20 28 44 52 42 2c 20 26 46 45 36 30 29 2e 20 |B (DRB, &FE60). | 00000440 49 66 20 61 6e 20 69 6e 74 65 72 72 75 70 74 20 |If an interrupt | 00000450 69 73 0d 67 65 6e 65 72 61 74 65 64 20 62 79 20 |is.generated by | 00000460 43 42 31 20 74 68 65 6e 20 79 6f 75 72 20 70 72 |CB1 then your pr| 00000470 6f 67 72 61 6d 20 73 68 6f 75 6c 64 20 65 78 61 |ogram should exa| 00000480 6d 69 6e 65 20 62 69 74 20 30 20 6f 66 20 44 52 |mine bit 0 of DR| 00000490 42 2e 20 49 66 20 62 69 74 20 30 0d 6f 66 20 44 |B. If bit 0.of D| 000004a0 52 42 20 69 73 20 73 65 74 20 58 20 69 73 20 64 |RB is set X is d| 000004b0 65 63 72 65 61 73 69 6e 67 2c 20 69 66 20 69 74 |ecreasing, if it| 000004c0 20 69 73 20 63 6c 65 61 72 20 58 20 69 73 20 69 | is clear X is i| 000004d0 6e 63 72 65 61 73 69 6e 67 2e 20 53 69 6d 69 6c |ncreasing. Simil| 000004e0 61 72 6c 79 0d 69 66 20 61 6e 20 69 6e 74 65 72 |arly.if an inter| 000004f0 72 75 70 74 20 69 73 20 67 65 6e 65 72 61 74 65 |rupt is generate| 00000500 64 20 62 79 20 43 42 32 20 74 68 65 6e 20 79 6f |d by CB2 then yo| 00000510 75 72 20 70 72 6f 67 72 61 6d 20 73 68 6f 75 6c |ur program shoul| 00000520 64 20 65 78 61 6d 69 6e 65 20 62 69 74 20 32 0d |d examine bit 2.| 00000530 6f 66 20 44 52 42 2e 20 49 66 20 62 69 74 20 32 |of DRB. If bit 2| 00000540 20 6f 66 20 44 52 42 20 69 73 20 73 65 74 20 59 | of DRB is set Y| 00000550 20 69 73 20 64 65 63 72 65 61 73 69 6e 67 2c 20 | is decreasing, | 00000560 69 66 20 69 74 20 69 73 20 63 6c 65 61 72 20 59 |if it is clear Y| 00000570 20 69 73 0d 69 6e 63 72 65 61 73 69 6e 67 2e 0d | is.increasing..| 00000580 0d 49 74 20 69 73 20 70 6f 73 73 69 62 6c 65 20 |.It is possible | 00000590 74 6f 20 6c 61 74 63 68 20 74 68 65 20 64 61 74 |to latch the dat| 000005a0 61 20 69 6e 20 44 52 42 20 73 6f 20 74 68 61 74 |a in DRB so that| 000005b0 20 74 68 65 20 76 61 6c 75 65 73 20 72 65 61 64 | the values read| 000005c0 20 66 72 6f 6d 20 74 68 65 0d 72 65 67 69 73 74 | from the.regist| 000005d0 65 72 20 61 72 65 20 74 68 6f 73 65 20 74 68 61 |er are those tha| 000005e0 74 20 77 65 72 65 20 70 72 65 73 65 6e 74 20 77 |t were present w| 000005f0 68 65 6e 20 61 20 63 68 61 6e 67 65 20 6f 66 20 |hen a change of | 00000600 73 69 67 6e 61 6c 20 6f 63 63 75 72 65 64 20 6f |signal occured o| 00000610 6e 0d 43 42 31 2e 20 54 68 69 73 20 6d 65 61 6e |n.CB1. This mean| 00000620 73 20 74 68 61 74 2c 20 69 66 20 6c 61 74 63 68 |s that, if latch| 00000630 69 6e 67 20 69 73 20 73 65 6c 65 63 74 65 64 2c |ing is selected,| 00000640 20 74 68 65 20 64 61 74 61 20 66 6f 72 20 6d 6f | the data for mo| 00000650 76 65 6d 65 6e 74 20 69 6e 0d 74 68 65 20 58 20 |vement in.the X | 00000660 64 69 72 65 63 74 69 6f 6e 20 77 69 6c 6c 20 72 |direction will r| 00000670 65 6d 61 69 6e 20 61 76 61 69 6c 61 62 6c 65 20 |emain available | 00000680 75 6e 74 69 6c 20 61 20 6e 65 77 20 6d 6f 76 65 |until a new move| 00000690 6d 65 6e 74 20 69 73 20 64 65 74 65 63 74 65 64 |ment is detected| 000006a0 2e 0d 54 68 69 73 20 77 6f 75 6c 64 20 62 65 20 |..This would be | 000006b0 76 65 72 79 20 75 73 65 66 75 6c 20 69 66 20 69 |very useful if i| 000006c0 74 20 77 61 73 20 61 6c 73 6f 20 61 76 61 69 6c |t was also avail| 000006d0 61 62 6c 65 20 66 6f 72 20 6d 6f 76 65 6d 65 6e |able for movemen| 000006e0 74 20 69 6e 20 74 68 65 20 59 0d 64 69 72 65 63 |t in the Y.direc| 000006f0 74 69 6f 6e 2c 20 62 75 74 20 6c 61 74 63 68 69 |tion, but latchi| 00000700 6e 67 20 69 73 20 6e 6f 74 20 61 76 61 69 6c 61 |ng is not availa| 00000710 62 6c 65 20 66 6f 72 20 73 69 67 6e 61 6c 73 20 |ble for signals | 00000720 6f 6e 20 43 42 32 2e 20 49 74 20 69 73 20 6f 6e |on CB2. It is on| 00000730 6c 79 0d 77 6f 72 74 68 20 73 65 6c 65 63 74 69 |ly.worth selecti| 00000740 6e 67 20 74 68 65 20 6c 61 74 63 68 69 6e 67 20 |ng the latching | 00000750 6d 6f 64 65 20 28 62 79 20 73 65 74 74 69 6e 67 |mode (by setting| 00000760 20 62 69 74 20 31 20 6f 66 20 74 68 65 20 41 43 | bit 1 of the AC| 00000770 52 20 61 74 20 26 46 45 36 42 29 0d 69 66 20 79 |R at &FE6B).if y| 00000780 6f 75 20 61 72 65 20 6f 6e 6c 79 20 69 6e 74 65 |ou are only inte| 00000790 72 65 73 74 65 64 20 69 6e 20 6d 6f 76 65 6d 65 |rested in moveme| 000007a0 6e 74 20 66 72 6f 6d 20 73 69 64 65 20 74 6f 20 |nt from side to | 000007b0 73 69 64 65 2e 20 49 6e 20 70 72 61 63 74 69 63 |side. In practic| 000007c0 65 20 74 68 69 73 0d 63 6f 75 6c 64 20 62 65 20 |e this.could be | 000007d0 75 73 65 66 75 6c 20 77 69 74 68 20 67 61 6d 65 |useful with game| 000007e0 73 20 73 6f 66 74 77 61 72 65 2e 0d 0d 42 65 63 |s software...Bec| 000007f0 61 75 73 65 20 6c 61 74 63 68 69 6e 67 20 69 73 |ause latching is| 00000800 20 75 6e 61 76 61 69 6c 61 62 6c 65 20 66 6f 72 | unavailable for| 00000810 20 6d 6f 76 65 6d 65 6e 74 73 20 69 6e 20 74 68 | movements in th| 00000820 65 20 59 20 70 6c 61 6e 65 20 74 68 65 20 6d 6f |e Y plane the mo| 00000830 75 73 65 0d 67 65 6e 65 72 61 74 65 64 20 69 6e |use.generated in| 00000840 74 65 72 72 75 70 74 73 20 68 61 76 65 20 74 6f |terrupts have to| 00000850 20 62 65 20 69 6e 74 65 72 63 65 70 74 65 64 20 | be intercepted | 00000860 61 74 20 74 68 65 20 68 69 67 68 20 70 72 69 6f |at the high prio| 00000870 72 69 74 79 20 49 52 51 31 56 0d 69 6e 74 65 72 |rity IRQ1V.inter| 00000880 72 75 70 74 20 76 65 63 74 6f 72 20 74 6f 20 65 |rupt vector to e| 00000890 6e 73 75 72 65 20 74 68 61 74 20 62 69 74 73 20 |nsure that bits | 000008a0 30 20 61 6e 64 20 32 20 6f 66 20 44 52 42 20 72 |0 and 2 of DRB r| 000008b0 65 66 6c 65 63 74 20 74 68 65 20 74 72 75 65 0d |eflect the true.| 000008c0 63 68 61 6e 67 65 20 6f 66 20 64 69 72 65 63 74 |change of direct| 000008d0 69 6f 6e 20 69 6e 20 74 68 65 20 58 20 61 6e 64 |ion in the X and| 000008e0 20 59 20 63 6f 6f 72 64 69 6e 61 74 65 73 2e 20 | Y coordinates. | 000008f0 49 66 20 74 68 65 20 69 6e 74 65 72 72 75 70 74 |If the interrupt| 00000900 73 20 61 72 65 0d 69 6e 74 65 72 63 65 70 74 65 |s are.intercepte| 00000910 64 20 61 74 20 74 68 65 20 6c 6f 77 20 70 72 69 |d at the low pri| 00000920 6f 72 69 74 79 20 49 52 51 32 56 20 69 6e 74 65 |ority IRQ2V inte| 00000930 72 72 75 70 74 20 76 65 63 74 6f 72 20 74 68 65 |rrupt vector the| 00000940 6e 20 74 68 65 0d 6e 6f 6e 2d 6c 61 74 63 68 65 |n the.non-latche| 00000950 64 20 44 52 42 20 6d 61 79 20 6f 72 20 6d 61 79 |d DRB may or may| 00000960 20 6e 6f 74 20 72 65 66 6c 65 63 74 20 74 68 65 | not reflect the| 00000970 20 64 69 72 65 63 74 69 6f 6e 20 6f 66 20 74 68 | direction of th| 00000980 65 20 6d 6f 75 73 65 0d 6d 6f 76 65 6d 65 6e 74 |e mouse.movement| 00000990 2e 20 49 6e 20 74 68 65 20 64 65 6d 6f 6e 73 74 |. In the demonst| 000009a0 72 61 74 69 6f 6e 20 70 72 6f 67 72 61 6d 73 20 |ration programs | 000009b0 77 68 69 63 68 20 72 65 76 65 63 74 6f 72 20 61 |which revector a| 000009c0 6e 20 69 6e 74 65 72 72 75 70 74 0d 76 65 63 74 |n interrupt.vect| 000009d0 6f 72 2c 20 49 52 51 31 56 20 69 73 20 75 73 65 |or, IRQ1V is use| 000009e0 64 20 61 6e 64 20 56 49 41 2d 42 20 69 73 20 69 |d and VIA-B is i| 000009f0 6e 20 74 68 65 20 6e 6f 6e 2d 6c 61 74 63 68 65 |n the non-latche| 00000a00 64 20 6d 6f 64 65 2e 0d 0d 54 68 65 20 70 72 6f |d mode...The pro| 00000a10 67 72 61 6d 20 4d 4f 55 53 45 20 69 6c 6c 75 73 |gram MOUSE illus| 00000a20 74 72 61 74 65 73 20 68 6f 77 20 74 68 65 20 49 |trates how the I| 00000a30 52 51 31 56 20 76 65 63 74 6f 72 20 69 73 20 72 |RQ1V vector is r| 00000a40 65 76 65 63 74 6f 72 65 64 20 74 6f 20 70 6f 69 |evectored to poi| 00000a50 6e 74 0d 74 6f 20 74 68 65 20 6e 65 77 20 63 6f |nt.to the new co| 00000a60 64 65 20 6c 61 62 65 6c 65 64 20 69 6e 74 65 72 |de labeled inter| 00000a70 72 75 70 74 2e 20 44 61 74 61 20 72 65 67 69 73 |rupt. 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In.thi| 00000bc0 73 20 65 78 61 6d 70 6c 65 20 74 68 65 20 69 6e |s example the in| 00000bd0 69 74 69 61 6c 20 63 6f 6f 72 64 69 6e 61 74 65 |itial coordinate| 00000be0 73 20 61 73 73 69 67 6e 65 64 20 74 6f 20 74 68 |s assigned to th| 00000bf0 65 20 63 75 72 72 65 6e 74 20 6d 6f 75 73 65 0d |e current mouse.| 00000c00 70 6f 73 69 74 69 6f 6e 20 61 72 65 20 30 2c 30 |position are 0,0| 00000c10 2e 20 54 68 65 20 69 6e 69 74 69 61 6c 20 63 6f |. The initial co| 00000c20 6f 72 64 69 6e 61 74 65 73 20 63 6f 75 6c 64 20 |ordinates could | 00000c30 62 65 20 61 6e 79 74 68 69 6e 67 20 79 6f 75 20 |be anything you | 00000c40 6c 69 6b 65 0d 77 69 74 68 69 6e 20 74 68 65 20 |like.within the | 00000c50 72 61 6e 67 65 20 66 72 6f 6d 20 30 20 74 6f 20 |range from 0 to | 00000c60 32 35 35 2e 0d 0d 41 6c 6c 20 74 68 65 20 65 78 |255...All the ex| 00000c70 61 6d 70 6c 65 20 70 72 6f 67 72 61 6d 73 20 69 |ample programs i| 00000c80 6e 20 74 68 69 73 20 73 65 72 69 65 73 20 75 73 |n this series us| 00000c90 65 20 61 20 72 61 6e 67 65 20 6f 66 20 66 72 6f |e a range of fro| 00000ca0 6d 20 30 20 74 6f 20 32 35 35 20 66 6f 72 0d 62 |m 0 to 255 for.b| 00000cb0 6f 74 68 20 74 68 65 20 58 20 61 6e 64 20 59 20 |oth the X and Y | 00000cc0 63 6f 6f 72 64 69 6e 61 74 65 73 2e 20 54 68 69 |coordinates. Thi| 00000cd0 73 20 73 69 6d 70 6c 69 66 69 65 73 20 74 68 65 |s simplifies the| 00000ce0 20 64 65 6d 6f 6e 73 74 72 61 74 69 6f 6e 20 70 | demonstration p| 00000cf0 72 6f 67 72 61 6d 73 0d 62 65 63 61 75 73 65 20 |rograms.because | 00000d00 6f 6e 6c 79 20 6f 6e 65 20 62 79 74 65 20 69 73 |only one byte is| 00000d10 20 75 73 65 64 20 74 6f 20 73 74 6f 72 65 20 65 | used to store e| 00000d20 61 63 68 20 63 6f 6f 72 64 69 6e 61 74 65 2e 20 |ach coordinate. | 00000d30 54 68 65 20 58 20 61 6e 64 20 59 0d 63 6f 6f 72 |The X and Y.coor| 00000d40 64 69 6e 61 74 65 73 20 63 61 6e 20 74 68 65 6e |dinates can then| 00000d50 20 62 65 20 72 65 61 64 20 77 69 74 68 20 74 68 | be read with th| 00000d60 65 20 42 41 53 49 43 20 3f 20 69 6e 64 69 72 65 |e BASIC ? indire| 00000d70 63 74 69 6f 6e 20 6f 70 65 72 61 74 6f 72 2e 20 |ction operator. | 00000d80 49 66 20 79 6f 75 0d 64 65 63 69 64 65 20 74 6f |If you.decide to| 00000d90 20 6d 6f 64 69 66 79 20 61 6e 79 20 6f 66 20 74 | modify any of t| 00000da0 68 65 20 64 65 6d 6f 6e 73 74 72 61 74 69 6f 6e |he demonstration| 00000db0 20 70 72 6f 67 72 61 6d 73 20 74 6f 20 75 73 65 | programs to use| 00000dc0 20 61 20 6c 61 72 67 65 72 20 72 61 6e 67 65 0d | a larger range.| 00000dd0 6f 66 20 63 6f 6f 72 64 69 6e 61 74 65 73 20 69 |of coordinates i| 00000de0 74 20 69 73 20 61 20 67 6f 6f 64 20 69 64 65 61 |t is a good idea| 00000df0 20 74 6f 20 75 73 65 20 66 6f 75 72 20 62 79 74 | to use four byt| 00000e00 65 73 20 66 6f 72 20 65 61 63 68 20 63 6f 6f 72 |es for each coor| 00000e10 64 69 6e 61 74 65 0d 65 76 65 6e 20 69 66 20 79 |dinate.even if y| 00000e20 6f 75 20 6f 6e 6c 79 20 69 6e 74 65 6e 64 20 74 |ou only intend t| 00000e30 6f 20 75 73 65 20 74 77 6f 20 6f 66 20 74 68 65 |o use two of the| 00000e40 20 66 6f 75 72 20 62 79 74 65 73 20 74 6f 20 73 | four bytes to s| 00000e50 74 6f 72 65 20 74 68 65 20 61 63 74 75 61 6c 0d |tore the actual.| 00000e60 6e 75 6d 62 65 72 2e 20 55 73 69 6e 67 20 66 6f |number. 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The mous| 000013d0 65 0d 63 6f 6f 72 64 69 6e 61 74 65 73 20 61 72 |e.coordinates ar| 000013e0 65 20 70 65 65 6b 65 64 20 66 72 6f 6d 20 74 68 |e peeked from th| 000013f0 65 20 7a 65 72 6f 20 70 61 67 65 20 6d 65 6d 6f |e zero page memo| 00001400 72 79 20 6c 6f 63 61 74 69 6f 6e 73 20 61 6e 64 |ry locations and| 00001410 20 64 69 73 70 6c 61 79 65 64 0d 69 6e 20 61 6e | displayed.in an| 00001420 20 65 6e 64 6c 65 73 73 20 6c 6f 6f 70 2e 20 43 | endless loop. C| 00001430 68 61 69 6e 20 74 68 65 20 70 72 6f 67 72 61 6d |hain the program| 00001440 20 61 6e 64 20 6d 6f 76 65 20 74 68 65 20 6d 6f | and move the mo| 00001450 75 73 65 20 61 72 6f 75 6e 64 20 74 6f 20 73 65 |use around to se| 00001460 65 20 74 68 65 0d 72 61 6e 67 65 20 61 6e 64 20 |e the.range and | 00001470 73 65 6e 73 69 74 69 76 69 74 79 20 6f 66 20 74 |sensitivity of t| 00001480 68 65 20 6d 6f 76 65 6d 65 6e 74 2e 20 54 6f 20 |he movement. To | 00001490 73 74 6f 70 20 74 68 65 20 70 72 6f 67 72 61 6d |stop the program| 000014a0 20 70 72 65 73 73 20 65 69 74 68 65 72 0d 74 68 | press either.th| 000014b0 65 20 45 73 63 61 70 65 20 6b 65 79 20 6f 72 20 |e Escape key or | 000014c0 74 68 65 20 42 72 65 61 6b 20 6b 65 79 2e 20 49 |the Break key. I| 000014d0 6e 20 6d 6f 64 75 6c 65 20 32 20 49 20 77 69 6c |n module 2 I wil| 000014e0 6c 20 73 68 6f 77 20 68 6f 77 20 74 68 65 20 70 |l show how the p| 000014f0 72 6f 67 72 61 6d 0d 4d 4f 55 53 45 20 63 61 6e |rogram.MOUSE can| 00001500 20 62 65 20 6d 6f 64 69 66 69 65 64 20 74 6f 20 | be modified to | 00001510 6d 61 6b 65 20 69 74 20 54 75 62 65 20 63 6f 6d |make it Tube com| 00001520 70 61 74 69 62 6c 65 2e 0d 0d 0d 20 20 20 31 30 |patible.... 10| 00001530 20 52 45 4d 3e 20 4d 4f 55 53 45 0d 20 20 20 32 | REM> MOUSE. 2| 00001540 30 20 44 49 4d 20 6d 63 6f 64 65 20 26 32 30 30 |0 DIM mcode &200| 00001550 20 3a 52 45 4d 3a 20 6d 61 63 68 69 6e 65 20 63 | :REM: machine c| 00001560 6f 64 65 20 61 74 20 6d 63 6f 64 65 0d 20 20 20 |ode at mcode. | 00001570 33 30 20 78 63 6f 6f 72 64 3d 26 38 30 20 3a 52 |30 xcoord=&80 :R| 00001580 45 4d 3a 20 78 20 63 6f 6f 72 64 69 6e 61 74 65 |EM: x coordinate| 00001590 2c 20 72 61 6e 67 65 20 30 2d 32 35 35 0d 20 20 |, range 0-255. | 000015a0 20 34 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20 20 | 130 P%=mcode. | 00001750 31 34 30 20 5b 20 20 20 20 20 20 20 4f 50 54 20 |140 [ OPT | 00001760 70 61 73 73 0d 20 20 31 35 30 20 20 20 20 20 20 |pass. 150 | 00001770 20 20 20 4c 44 58 20 69 72 71 31 76 20 20 20 20 | LDX irq1v | 00001780 20 5c 20 63 75 72 72 65 6e 74 20 70 72 69 6d 61 | \ current prima| 00001790 72 79 20 69 6e 74 65 72 72 75 70 74 20 76 65 63 |ry interrupt vec| 000017a0 74 6f 72 2c 20 6c 6f 77 20 62 79 74 65 0d 20 20 |tor, low byte. | 000017b0 31 36 30 20 20 20 20 20 20 20 20 20 4c 44 59 20 |160 LDY | 000017c0 69 72 71 31 76 2b 31 20 20 20 5c 20 63 75 72 72 |irq1v+1 \ curr| 000017d0 65 6e 74 20 70 72 69 6d 61 72 79 20 69 6e 74 65 |ent primary inte| 000017e0 72 72 75 70 74 20 76 65 63 74 6f 72 2c 20 68 69 |rrupt vector, hi| 000017f0 67 68 20 62 79 74 65 0d 20 20 31 37 30 20 20 20 |gh byte. 170 | 00001800 20 20 20 20 20 20 43 50 59 20 23 69 6e 74 65 72 | CPY #inter| 00001810 72 75 70 74 20 44 49 56 20 32 35 36 20 5c 20 63 |rupt DIV 256 \ c| 00001820 6f 6d 70 61 72 65 20 68 69 67 68 20 62 79 74 65 |ompare high byte| 00001830 0d 20 20 31 38 30 20 20 20 20 20 20 20 20 20 42 |. 180 B| 00001840 45 51 20 64 69 73 61 62 6c 65 20 20 20 5c 20 72 |EQ disable \ r| 00001850 65 73 74 6f 72 65 20 6f 6c 64 20 76 65 63 74 6f |estore old vecto| 00001860 72 20 69 66 20 61 6c 74 65 72 65 64 0d 20 20 31 |r if altered. 1| 00001870 39 30 20 20 20 20 20 20 20 20 20 53 54 58 20 6f |90 STX o| 00001880 6c 64 69 72 71 31 76 20 20 5c 20 73 61 76 65 20 |ldirq1v \ save | 00001890 6f 72 69 67 69 6e 61 6c 20 69 72 71 31 20 76 65 |original irq1 ve| 000018a0 63 74 6f 72 2c 20 6c 6f 77 20 62 79 74 65 0d 20 |ctor, low byte. | 000018b0 20 32 30 30 20 20 20 20 20 20 20 20 20 53 54 59 | 200 STY| 000018c0 20 6f 6c 64 69 72 71 31 76 2b 31 20 5c 20 73 61 | oldirq1v+1 \ sa| 000018d0 76 65 20 6f 72 69 67 69 6e 61 6c 20 69 72 71 31 |ve original irq1| 000018e0 20 76 65 63 74 6f 72 2c 20 68 69 67 68 20 62 79 | vector, high by| 000018f0 74 65 0d 20 20 32 31 30 20 20 20 20 20 20 20 20 |te. 210 | 00001900 20 4c 44 58 20 23 69 6e 74 65 72 72 75 70 74 20 | LDX #interrupt | 00001910 4d 4f 44 20 32 35 36 20 5c 20 6e 65 77 20 69 72 |MOD 256 \ new ir| 00001920 71 31 20 76 65 63 74 6f 72 2c 20 6c 6f 77 20 62 |q1 vector, low b| 00001930 79 74 65 0d 20 20 32 32 30 20 20 20 20 20 20 20 |yte. 220 | 00001940 20 20 4c 44 59 20 23 69 6e 74 65 72 72 75 70 74 | LDY #interrupt| 00001950 20 44 49 56 20 32 35 36 20 5c 20 6e 65 77 20 69 | DIV 256 \ new i| 00001960 72 71 31 20 76 65 63 74 6f 72 2c 20 68 69 67 68 |rq1 vector, high| 00001970 20 62 79 74 65 0d 20 20 32 33 30 20 20 20 20 20 | byte. 230 | 00001980 20 20 20 20 53 45 49 20 20 20 20 20 20 20 20 20 | SEI | 00001990 20 20 5c 20 73 65 74 20 69 6e 74 65 72 72 75 70 | \ set interrup| 000019a0 74 20 64 69 73 61 62 6c 65 20 66 6c 61 67 0d 20 |t disable flag. | 000019b0 20 32 34 30 20 20 20 20 20 20 20 20 20 53 54 58 | 240 STX| 000019c0 20 69 72 71 31 76 20 20 20 20 20 5c 20 61 6c 74 | irq1v \ alt| 000019d0 65 72 20 69 72 71 31 20 76 65 63 74 6f 72 2c 20 |er irq1 vector, | 000019e0 6c 6f 77 20 62 79 74 65 0d 20 20 32 35 30 20 20 |low byte. 250 | 000019f0 20 20 20 20 20 20 20 53 54 59 20 69 72 71 31 76 | STY irq1v| 00001a00 2b 31 20 20 20 5c 20 61 6c 74 65 72 20 69 72 71 |+1 \ alter irq| 00001a10 31 20 76 65 63 74 6f 72 2c 20 68 69 67 68 20 62 |1 vector, high b| 00001a20 79 74 65 0d 20 20 32 36 30 20 20 20 20 20 20 20 |yte. 260 | 00001a30 20 20 43 4c 49 20 20 20 20 20 20 20 20 20 20 20 | CLI | 00001a40 5c 20 63 6c 65 61 72 20 69 6e 74 65 72 72 75 70 |\ clear interrup| 00001a50 74 20 64 69 73 61 62 6c 65 20 66 6c 61 67 0d 20 |t disable flag. | 00001a60 20 32 37 30 20 20 20 20 20 20 20 20 20 4c 44 41 | 270 LDA| 00001a70 20 23 26 39 38 20 20 20 20 20 20 5c 20 25 31 30 | #&98 \ %10| 00001a80 30 31 31 30 30 30 2c 20 69 65 2e 20 65 6e 61 62 |011000, ie. enab| 00001a90 6c 65 20 43 42 31 2f 32 0d 20 20 32 38 30 20 20 |le CB1/2. 280 | 00001aa0 20 20 20 20 20 20 20 53 54 41 20 69 65 72 20 20 | STA ier | 00001ab0 20 20 20 20 20 5c 20 69 6e 74 65 72 72 75 70 74 | \ interrupt| 00001ac0 20 65 6e 61 62 6c 65 20 72 65 67 69 73 74 65 72 | enable register| 00001ad0 0d 20 20 32 39 30 20 20 20 20 20 20 20 20 20 4c |. 290 L| 00001ae0 44 41 20 70 63 72 20 20 20 20 20 20 20 5c 20 70 |DA pcr \ p| 00001af0 65 72 69 70 68 65 72 61 6c 20 63 6f 6e 74 72 6f |eripheral contro| 00001b00 6c 20 72 65 67 69 73 74 65 72 0d 20 20 33 30 30 |l register. 300| 00001b10 20 20 20 20 20 20 20 20 20 41 4e 44 20 23 26 30 | AND #&0| 00001b20 46 20 20 20 20 20 20 5c 20 41 4e 44 20 77 69 74 |F \ AND wit| 00001b30 68 20 25 30 30 30 30 31 31 31 31 2c 20 69 65 20 |h %00001111, ie | 00001b40 63 6c 65 61 72 20 62 69 74 73 20 34 2d 37 0d 20 |clear bits 4-7. | 00001b50 20 33 31 30 20 20 20 20 20 20 20 20 20 4f 52 41 | 310 ORA| 00001b60 20 23 26 35 30 20 20 20 20 20 20 5c 20 4f 52 20 | #&50 \ OR | 00001b70 77 69 74 68 20 25 30 31 30 31 30 30 30 30 2c 20 |with %01010000, | 00001b80 69 65 2e 20 73 65 74 20 62 69 74 73 20 34 20 61 |ie. set bits 4 a| 00001b90 6e 64 20 36 0d 20 20 33 32 30 20 20 20 20 20 20 |nd 6. 320 | 00001ba0 20 20 20 53 54 41 20 70 63 72 20 20 20 20 20 20 | STA pcr | 00001bb0 20 5c 20 69 6e 74 65 72 72 75 70 74 20 6f 6e 20 | \ interrupt on | 00001bc0 2b 76 65 20 74 72 61 6e 73 69 74 69 6f 6e 2c 20 |+ve transition, | 00001bd0 43 42 32 20 69 6e 70 75 74 2c 0d 20 20 20 20 20 |CB2 input,. | 00001be0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00001bf0 20 20 20 20 20 20 20 5c 20 44 52 42 20 74 6f 20 | \ DRB to | 00001c00 63 6c 65 61 72 0d 20 20 33 33 30 20 20 20 20 20 |clear. 330 | 00001c10 20 20 20 20 4c 44 41 20 23 26 30 30 20 20 20 20 | LDA #&00 | 00001c20 20 20 5c 20 75 73 65 72 20 70 6f 72 74 20 69 6e | \ user port in| 00001c30 70 75 74 0d 20 20 33 34 30 20 20 20 20 20 20 20 |put. 340 | 00001c40 20 20 53 54 41 20 64 64 72 62 20 20 20 20 20 20 | STA ddrb | 00001c50 5c 20 64 61 74 61 20 64 69 72 65 63 74 69 6f 6e |\ data direction| 00001c60 20 72 65 67 69 73 74 65 72 20 42 0d 20 20 33 35 | register B. 35| 00001c70 30 20 20 20 20 20 20 20 20 20 53 54 41 20 78 63 |0 STA xc| 00001c80 6f 6f 72 64 20 20 20 20 5c 20 69 6e 69 74 69 61 |oord \ initia| 00001c90 6c 20 76 61 6c 75 65 20 66 6f 72 20 78 20 63 6f |l value for x co| 00001ca0 6f 72 64 69 6e 61 74 65 0d 20 20 33 36 30 20 20 |ordinate. 360 | 00001cb0 20 20 20 20 20 20 20 53 54 41 20 79 63 6f 6f 72 | STA ycoor| 00001cc0 64 20 20 20 20 5c 20 69 6e 69 74 69 61 6c 20 76 |d \ initial v| 00001cd0 61 6c 75 65 20 66 6f 72 20 79 20 63 6f 6f 72 64 |alue for y coord| 00001ce0 69 6e 61 74 65 0d 20 20 33 37 30 20 20 20 20 20 |inate. 370 | 00001cf0 20 20 20 20 52 54 53 20 20 20 20 20 20 20 20 20 | RTS | 00001d00 20 20 5c 20 72 65 74 75 72 6e 20 74 6f 20 42 41 | \ return to BA| 00001d10 53 49 43 0d 20 20 33 38 30 20 2e 64 69 73 61 62 |SIC. 380 .disab| 00001d20 6c 65 0d 20 20 33 39 30 20 20 20 20 20 20 20 20 |le. 390 | 00001d30 20 4c 44 41 20 23 26 31 38 20 20 20 20 20 20 5c | LDA #&18 \| 00001d40 20 25 30 30 30 31 31 30 30 30 2c 20 72 65 61 64 | %00011000, read| 00001d50 79 20 74 6f 20 63 6c 65 61 72 20 62 69 74 73 20 |y to clear bits | 00001d60 33 20 61 6e 64 20 34 20 6f 66 20 69 65 72 0d 20 |3 and 4 of ier. | 00001d70 20 34 30 30 20 20 20 20 20 20 20 20 20 4c 44 58 | 400 LDX| 00001d80 20 6f 6c 64 69 72 71 31 76 20 20 5c 20 6f 72 69 | oldirq1v \ ori| 00001d90 67 69 6e 61 6c 20 69 72 71 31 20 76 65 63 74 6f |ginal irq1 vecto| 00001da0 72 2c 20 6c 6f 77 20 62 79 74 65 0d 20 20 34 31 |r, low byte. 41| 00001db0 30 20 20 20 20 20 20 20 20 20 4c 44 59 20 6f 6c |0 LDY ol| 00001dc0 64 69 72 71 31 76 2b 31 20 5c 20 6f 72 69 67 69 |dirq1v+1 \ origi| 00001dd0 6e 61 6c 20 69 72 71 31 20 76 65 63 74 6f 72 2c |nal irq1 vector,| 00001de0 20 68 69 67 68 20 62 79 74 65 0d 20 20 34 32 30 | high byte. 420| 00001df0 20 20 20 20 20 20 20 20 20 53 45 49 20 20 20 20 | SEI | 00001e00 20 20 20 20 20 20 20 5c 20 73 65 74 20 69 6e 74 | \ set int| 00001e10 65 72 72 75 70 74 20 64 69 73 61 62 6c 65 20 66 |errupt disable f| 00001e20 6c 61 67 0d 20 20 34 33 30 20 20 20 20 20 20 20 |lag. 430 | 00001e30 20 20 53 54 41 20 69 65 72 20 20 20 20 20 20 20 | STA ier | 00001e40 5c 20 69 6e 74 65 72 72 75 70 74 20 65 6e 61 62 |\ interrupt enab| 00001e50 6c 65 20 72 65 67 69 73 74 65 72 0d 20 20 34 34 |le register. 44| 00001e60 30 20 20 20 20 20 20 20 20 20 4c 44 41 20 70 63 |0 LDA pc| 00001e70 72 20 20 20 20 20 20 20 5c 20 70 65 72 69 70 68 |r \ periph| 00001e80 65 72 61 6c 20 63 6f 6e 74 72 6f 6c 20 72 65 67 |eral control reg| 00001e90 69 73 74 65 72 0d 20 20 34 35 30 20 20 20 20 20 |ister. 450 | 00001ea0 20 20 20 20 41 4e 44 20 23 26 30 46 20 20 20 20 | AND #&0F | 00001eb0 20 20 5c 20 63 6c 65 61 72 20 62 69 74 73 20 34 | \ clear bits 4| 00001ec0 2d 37 0d 20 20 34 36 30 20 20 20 20 20 20 20 20 |-7. 460 | 00001ed0 20 53 54 41 20 70 63 72 20 20 20 20 20 20 20 5c | STA pcr \| 00001ee0 20 70 65 72 69 70 68 65 72 61 6c 20 63 6f 6e 74 | peripheral cont| 00001ef0 72 6f 6c 20 72 65 67 69 73 74 65 72 0d 20 20 34 |rol register. 4| 00001f00 37 30 20 20 20 20 20 20 20 20 20 53 54 58 20 69 |70 STX i| 00001f10 72 71 31 76 20 20 20 20 20 5c 20 72 65 73 74 6f |rq1v \ resto| 00001f20 72 65 20 74 68 65 20 6f 72 69 67 69 6e 61 6c 20 |re the original | 00001f30 69 72 71 31 20 76 65 63 74 6f 72 2c 20 6c 6f 77 |irq1 vector, low| 00001f40 20 62 79 74 65 0d 20 20 34 38 30 20 20 20 20 20 | byte. 480 | 00001f50 20 20 20 20 53 54 59 20 69 72 71 31 76 2b 31 20 | STY irq1v+1 | 00001f60 20 20 5c 20 72 65 73 74 6f 72 65 20 74 68 65 20 | \ restore the | 00001f70 6f 72 69 67 69 6e 61 6c 20 69 72 71 31 20 76 65 |original irq1 ve| 00001f80 63 74 6f 72 2c 20 68 69 67 68 20 62 79 74 65 0d |ctor, high byte.| 00001f90 20 20 34 39 30 20 20 20 20 20 20 20 20 20 43 4c | 490 CL| 00001fa0 49 20 20 20 20 20 20 20 20 20 20 20 5c 20 63 6c |I \ cl| 00001fb0 65 61 72 20 69 6e 74 65 72 72 75 70 74 20 64 69 |ear interrupt di| 00001fc0 73 61 62 6c 65 20 66 6c 61 67 0d 20 20 35 30 30 |sable flag. 500| 00001fd0 20 20 20 20 20 20 20 20 20 52 54 53 20 20 20 20 | RTS | 00001fe0 20 20 20 20 20 20 20 5c 20 72 65 74 75 72 6e 20 | \ return | 00001ff0 74 6f 20 42 41 53 49 43 0d 20 20 35 31 30 20 2e |to BASIC. 510 .| 00002000 69 6e 74 65 72 72 75 70 74 0d 20 20 35 32 30 20 |interrupt. 520 | 00002010 20 20 20 20 20 20 20 20 4c 44 41 20 73 61 76 65 | LDA save| 00002020 72 65 67 20 20 20 5c 20 69 6e 74 65 72 72 75 70 |reg \ interrup| 00002030 74 20 61 63 63 75 6d 75 6c 61 74 6f 72 20 73 61 |t accumulator sa| 00002040 76 65 20 72 65 67 69 73 74 65 72 0d 20 20 35 33 |ve register. 53| 00002050 30 20 20 20 20 20 20 20 20 20 50 48 41 20 20 20 |0 PHA | 00002060 20 20 20 20 20 20 20 20 5c 20 61 6e 64 20 70 75 | \ and pu| 00002070 73 68 20 69 74 20 6f 6e 20 74 68 65 20 73 74 61 |sh it on the sta| 00002080 63 6b 0d 20 20 35 34 30 20 20 20 20 20 20 20 20 |ck. 540 | 00002090 20 4c 44 41 20 69 66 72 20 20 20 20 20 20 20 5c | LDA ifr \| 000020a0 20 69 6e 74 65 72 72 75 70 74 20 66 6c 61 67 20 | interrupt flag | 000020b0 72 65 67 69 73 74 65 72 0d 20 20 35 35 30 20 20 |register. 550 | 000020c0 20 20 20 20 20 20 20 42 50 4c 20 6e 6f 74 75 73 | BPL notus| 000020d0 65 72 20 20 20 5c 20 62 69 74 20 37 20 69 73 20 |er \ bit 7 is | 000020e0 73 65 74 20 69 66 20 56 49 41 2d 42 20 69 6e 74 |set if VIA-B int| 000020f0 65 72 72 75 70 74 0d 20 20 35 36 30 20 20 20 20 |errupt. 560 | 00002100 20 20 20 20 20 41 4e 44 20 23 26 31 38 20 20 20 | AND #&18 | 00002110 20 20 20 5c 20 41 4e 44 20 77 69 74 68 20 25 30 | \ AND with %0| 00002120 30 30 31 31 30 30 30 2c 20 69 65 2e 20 74 65 73 |0011000, ie. tes| 00002130 74 20 62 69 74 73 20 33 20 61 6e 64 20 34 0d 20 |t bits 3 and 4. | 00002140 20 35 37 30 20 20 20 20 20 20 20 20 20 42 45 51 | 570 BEQ| 00002150 20 6e 6f 74 75 73 65 72 20 20 20 5c 20 65 78 69 | notuser \ exi| 00002160 74 20 69 66 20 6e 6f 74 20 43 42 31 20 6f 72 20 |t if not CB1 or | 00002170 43 42 32 0d 20 20 35 38 30 20 20 20 20 20 20 20 |CB2. 580 | 00002180 20 20 41 4e 44 20 23 26 31 30 20 20 20 20 20 20 | AND #&10 | 00002190 5c 20 41 4e 44 20 77 69 74 68 20 25 30 30 30 31 |\ AND with %0001| 000021a0 30 30 30 30 2c 20 69 65 2e 20 74 65 73 74 20 43 |0000, ie. test C| 000021b0 42 31 0d 20 20 35 39 30 20 20 20 20 20 20 20 20 |B1. 590 | 000021c0 20 42 4e 45 20 78 70 75 6c 73 65 20 20 20 20 5c | BNE xpulse \| 000021d0 20 62 69 74 20 34 20 73 65 74 20 66 6f 72 20 61 | bit 4 set for a| 000021e0 6e 20 58 20 64 69 72 65 63 74 69 6f 6e 20 6d 6f |n X direction mo| 000021f0 76 65 6d 65 6e 74 0d 20 20 36 30 30 20 20 20 20 |vement. 600 | 00002200 20 20 20 20 20 4c 44 41 20 64 72 62 20 20 20 20 | LDA drb | 00002210 20 20 20 5c 20 59 20 64 69 72 65 63 74 69 6f 6e | \ Y direction| 00002220 2c 20 6c 6f 61 64 20 64 61 74 61 20 72 65 67 69 |, load data regi| 00002230 73 74 65 72 20 42 0d 20 20 36 31 30 20 20 20 20 |ster B. 610 | 00002240 20 20 20 20 20 41 4e 44 20 23 26 30 34 20 20 20 | AND #&04 | 00002250 20 20 20 5c 20 41 4e 44 20 77 69 74 68 20 25 30 | \ AND with %0| 00002260 30 30 30 30 31 30 30 2c 20 69 65 2e 20 74 65 73 |0000100, ie. tes| 00002270 74 20 62 69 74 20 32 0d 20 20 36 32 30 20 20 20 |t bit 2. 620 | 00002280 20 20 20 20 20 20 42 4e 45 20 79 64 6f 77 6e 20 | BNE ydown | 00002290 20 20 20 20 5c 20 69 66 20 62 69 74 20 32 20 69 | \ if bit 2 i| 000022a0 73 20 73 65 74 20 74 68 65 6e 20 59 20 69 73 20 |s set then Y is | 000022b0 67 6f 69 6e 67 20 64 6f 77 6e 0d 20 20 36 33 30 |going down. 630| 000022c0 20 20 20 20 20 20 20 20 20 49 4e 43 20 79 63 6f | INC yco| 000022d0 6f 72 64 20 20 20 20 5c 20 59 20 69 73 20 67 6f |ord \ Y is go| 000022e0 69 6e 67 20 75 70 20 73 6f 20 69 6e 63 72 65 6d |ing up so increm| 000022f0 65 6e 74 20 59 20 63 6f 6f 72 64 69 6e 61 74 65 |ent Y coordinate| 00002300 0d 20 20 36 34 30 20 20 20 20 20 20 20 20 20 42 |. 640 B| 00002310 4e 45 20 65 78 69 74 20 20 20 20 20 20 5c 20 62 |NE exit \ b| 00002320 72 61 6e 63 68 20 69 66 20 69 6e 20 74 68 65 20 |ranch if in the | 00002330 72 61 6e 67 65 20 31 20 74 6f 20 32 35 35 0d 20 |range 1 to 255. | 00002340 20 36 35 30 20 20 20 20 20 20 20 20 20 42 45 51 | 650 BEQ| 00002350 20 64 65 63 79 20 20 20 20 20 20 5c 20 69 66 20 | decy \ if | 00002360 7a 65 72 6f 20 74 68 65 6e 20 61 6c 74 65 72 20 |zero then alter | 00002370 74 6f 20 32 35 35 0d 20 20 36 36 30 20 2e 79 64 |to 255. 660 .yd| 00002380 6f 77 6e 0d 20 20 36 37 30 20 20 20 20 20 20 20 |own. 670 | 00002390 20 20 4c 44 41 20 79 63 6f 6f 72 64 20 20 20 20 | LDA ycoord | 000023a0 5c 20 6c 6f 61 64 20 59 20 63 6f 6f 72 64 69 6e |\ load Y coordin| 000023b0 61 74 65 0d 20 20 36 38 30 20 20 20 20 20 20 20 |ate. 680 | 000023c0 20 20 42 45 51 20 65 78 69 74 20 20 20 20 20 20 | BEQ exit | 000023d0 5c 20 62 72 61 6e 63 68 20 69 66 20 7a 65 72 6f |\ branch if zero| 000023e0 20 62 65 63 61 75 73 65 20 69 74 20 63 61 6e 27 | because it can'| 000023f0 74 20 67 6f 20 61 6e 79 20 6c 6f 77 65 72 0d 20 |t go any lower. | 00002400 20 36 39 30 20 2e 64 65 63 79 0d 20 20 37 30 30 | 690 .decy. 700| 00002410 20 20 20 20 20 20 20 20 20 44 45 43 20 79 63 6f | DEC yco| 00002420 6f 72 64 20 20 20 20 5c 20 72 65 64 75 63 65 20 |ord \ reduce | 00002430 59 20 63 6f 6f 72 64 69 6e 61 74 65 20 62 79 20 |Y coordinate by | 00002440 31 0d 20 20 37 31 30 20 20 20 20 20 20 20 20 20 |1. 710 | 00002450 4a 4d 50 20 65 78 69 74 20 20 20 20 20 20 5c 20 |JMP exit \ | 00002460 72 65 73 74 6f 72 65 20 69 6e 74 65 72 72 75 70 |restore interrup| 00002470 74 20 61 63 63 75 6d 75 6c 61 74 6f 72 20 73 61 |t accumulator sa| 00002480 76 65 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 |ve. | 00002490 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 5c | \| 000024a0 20 72 65 67 69 73 74 65 72 20 61 6e 64 20 52 54 | register and RT| 000024b0 49 0d 20 20 37 32 30 20 2e 78 70 75 6c 73 65 0d |I. 720 .xpulse.| 000024c0 20 20 37 33 30 20 20 20 20 20 20 20 20 20 4c 44 | 730 LD| 000024d0 41 20 64 72 62 20 20 20 20 20 20 20 5c 20 64 61 |A drb \ da| 000024e0 74 61 20 72 65 67 69 73 74 65 72 20 42 0d 20 20 |ta register B. | 000024f0 37 34 30 20 20 20 20 20 20 20 20 20 52 4f 52 20 |740 ROR | 00002500 41 20 20 20 20 20 20 20 20 20 5c 20 62 69 74 20 |A \ bit | 00002510 30 20 69 6e 74 6f 20 63 61 72 72 79 0d 20 20 37 |0 into carry. 7| 00002520 35 30 20 20 20 20 20 20 20 20 20 42 43 53 20 78 |50 BCS x| 00002530 64 6f 77 6e 20 20 20 20 20 5c 20 58 20 69 73 20 |down \ X is | 00002540 67 6f 69 6e 67 20 64 6f 77 6e 20 69 66 20 62 69 |going down if bi| 00002550 74 20 30 20 69 73 20 73 65 74 0d 20 20 37 36 30 |t 0 is set. 760| 00002560 20 20 20 20 20 20 20 20 20 49 4e 43 20 78 63 6f | INC xco| 00002570 6f 72 64 20 20 20 20 5c 20 58 20 69 73 20 67 6f |ord \ X is go| 00002580 69 6e 67 20 75 70 20 69 66 20 62 69 74 20 30 20 |ing up if bit 0 | 00002590 69 73 20 63 6c 65 61 72 0d 20 20 37 37 30 20 20 |is clear. 770 | 000025a0 20 20 20 20 20 20 20 42 4e 45 20 65 78 69 74 20 | BNE exit | 000025b0 20 20 20 20 20 5c 20 65 78 69 74 20 69 66 20 58 | \ exit if X| 000025c0 20 63 6f 6f 72 64 69 6e 61 74 65 20 69 73 20 69 | coordinate is i| 000025d0 6e 20 74 68 65 20 72 61 6e 67 65 0d 20 20 20 20 |n the range. | 000025e0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 000025f0 20 20 20 20 20 20 20 20 5c 20 66 72 6f 6d 20 31 | \ from 1| 00002600 20 74 6f 20 32 35 35 0d 20 20 37 38 30 20 20 20 | to 255. 780 | 00002610 20 20 20 20 20 20 42 45 51 20 64 65 63 78 20 20 | BEQ decx | 00002620 20 20 20 20 5c 20 69 66 20 58 20 63 6f 6f 72 64 | \ if X coord| 00002630 69 6e 61 74 65 20 3d 20 30 20 74 68 65 6e 20 6d |inate = 0 then m| 00002640 61 6b 65 20 69 74 20 32 35 35 0d 20 20 37 39 30 |ake it 255. 790| 00002650 20 2e 78 64 6f 77 6e 0d 20 20 38 30 30 20 20 20 | .xdown. 800 | 00002660 20 20 20 20 20 20 4c 44 41 20 78 63 6f 6f 72 64 | LDA xcoord| 00002670 20 20 20 20 5c 20 6c 6f 61 64 20 58 20 63 6f 6f | \ load X coo| 00002680 72 64 69 6e 61 74 65 0d 20 20 38 31 30 20 20 20 |rdinate. 810 | 00002690 20 20 20 20 20 20 42 45 51 20 65 78 69 74 20 20 | BEQ exit | 000026a0 20 20 20 20 5c 20 69 66 20 69 74 20 69 73 20 7a | \ if it is z| 000026b0 65 72 6f 20 69 74 20 63 61 6e 27 74 20 67 6f 20 |ero it can't go | 000026c0 61 6e 79 20 6c 6f 77 65 72 0d 20 20 38 32 30 20 |any lower. 820 | 000026d0 2e 64 65 63 78 0d 20 20 38 33 30 20 20 20 20 20 |.decx. 830 | 000026e0 20 20 20 20 44 45 43 20 78 63 6f 6f 72 64 20 20 | DEC xcoord | 000026f0 20 20 5c 20 64 65 63 72 65 61 73 65 20 58 20 63 | \ decrease X c| 00002700 6f 6f 72 64 69 6e 61 74 65 20 62 79 20 31 0d 20 |oordinate by 1. | 00002710 20 38 34 30 20 2e 65 78 69 74 0d 20 20 38 35 30 | 840 .exit. 850| 00002720 20 20 20 20 20 20 20 20 20 50 4c 41 20 20 20 20 | PLA | 00002730 20 20 20 20 20 20 20 5c 20 70 75 6c 6c 20 69 6e | \ pull in| 00002740 74 65 72 72 75 70 74 20 61 63 63 75 6d 75 6c 61 |terrupt accumula| 00002750 74 6f 72 20 73 61 76 65 0d 20 20 20 20 20 20 20 |tor save. | 00002760 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00002770 20 20 20 20 20 5c 20 72 65 67 69 73 74 65 72 20 | \ register | 00002780 6f 66 66 20 74 68 65 20 73 74 61 63 6b 0d 20 20 |off the stack. | 00002790 38 36 30 20 20 20 20 20 20 20 20 20 53 54 41 20 |860 STA | 000027a0 73 61 76 65 72 65 67 20 20 20 5c 20 61 6e 64 20 |savereg \ and | 000027b0 72 65 73 74 6f 72 65 20 7a 65 72 6f 20 70 61 67 |restore zero pag| 000027c0 65 0d 20 20 38 37 30 20 20 20 20 20 20 20 20 20 |e. 870 | 000027d0 52 54 49 20 20 20 20 20 20 20 20 20 20 20 5c 20 |RTI \ | 000027e0 72 65 74 75 72 6e 20 66 72 6f 6d 20 69 6e 74 65 |return from inte| 000027f0 72 72 75 70 74 0d 20 20 38 38 30 20 2e 6e 6f 74 |rrupt. 880 .not| 00002800 75 73 65 72 0d 20 20 38 39 30 20 20 20 20 20 20 |user. 890 | 00002810 20 20 20 50 4c 41 20 20 20 20 20 20 20 20 20 20 | PLA | 00002820 20 5c 20 70 75 6c 6c 20 74 68 65 20 69 6e 74 65 | \ pull the inte| 00002830 72 72 75 70 74 20 61 63 63 75 6d 75 6c 61 74 6f |rrupt accumulato| 00002840 72 20 73 61 76 65 0d 20 20 20 20 20 20 20 20 20 |r save. | 00002850 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00002860 20 20 20 5c 20 72 65 67 69 73 74 65 72 20 6f 66 | \ register of| 00002870 66 20 74 68 65 20 73 74 61 63 6b 0d 20 20 39 30 |f the stack. 90| 00002880 30 20 20 20 20 20 20 20 20 20 53 54 41 20 73 61 |0 STA sa| 00002890 76 65 72 65 67 20 20 20 5c 20 72 65 73 74 6f 72 |vereg \ restor| 000028a0 65 20 74 68 65 20 7a 65 72 6f 20 70 61 67 65 20 |e the zero page | 000028b0 61 64 64 72 65 73 73 0d 20 20 39 31 30 20 20 20 |address. 910 | 000028c0 20 20 20 20 20 20 4a 4d 50 20 28 6f 6c 64 69 72 | JMP (oldir| 000028d0 71 31 76 29 20 5c 20 65 78 69 74 20 76 69 61 20 |q1v) \ exit via | 000028e0 74 68 65 20 6f 72 69 67 69 6e 61 6c 20 76 65 63 |the original vec| 000028f0 74 6f 72 0d 20 20 39 32 30 20 2e 6f 6c 64 69 72 |tor. 920 .oldir| 00002900 71 31 76 0d 20 20 39 33 30 20 20 20 20 20 20 20 |q1v. 930 | 00002910 20 20 45 51 55 57 20 26 30 30 20 20 20 20 20 20 | EQUW &00 | 00002920 5c 20 6f 72 69 67 69 6e 61 6c 20 69 72 71 31 76 |\ original irq1v| 00002930 0d 20 20 39 34 30 20 2e 6c 61 73 74 62 79 74 65 |. 940 .lastbyte| 00002940 0d 20 20 39 35 30 20 5d 0d 20 20 39 36 30 20 4e |. 950 ]. 960 N| 00002950 45 58 54 0d 20 20 39 37 30 20 43 41 4c 4c 20 6d |EXT. 970 CALL m| 00002960 63 6f 64 65 0d 20 20 39 38 30 20 4d 4f 44 45 37 |code. 980 MODE7| 00002970 0d 20 20 39 39 30 20 6d 6f 75 73 65 24 3d 43 48 |. 990 mouse$=CH| 00002980 52 24 31 34 31 2b 43 48 52 24 31 33 32 2b 43 48 |R$141+CHR$132+CH| 00002990 52 24 31 35 37 2b 43 48 52 24 31 33 31 2b 0d 20 |R$157+CHR$131+. | 000029a0 20 20 20 20 20 22 4d 6f 75 73 65 20 63 6f 6f 72 | "Mouse coor| 000029b0 64 69 6e 61 74 65 73 2c 20 72 61 6e 67 65 20 26 |dinates, range &| 000029c0 30 30 2d 26 46 46 20 20 22 2b 43 48 52 24 31 35 |00-&FF "+CHR$15| 000029d0 36 0d 20 31 30 30 30 20 50 52 49 4e 54 54 41 42 |6. 1000 PRINTTAB| 000029e0 28 30 2c 31 29 6d 6f 75 73 65 24 0d 20 31 30 31 |(0,1)mouse$. 101| 000029f0 30 20 50 52 49 4e 54 54 41 42 28 30 2c 32 29 6d |0 PRINTTAB(0,2)m| 00002a00 6f 75 73 65 24 0d 20 31 30 32 30 20 56 44 55 32 |ouse$. 1020 VDU2| 00002a10 33 2c 31 2c 30 3b 30 3b 30 3b 30 3b 0d 20 31 30 |3,1,0;0;0;0;. 10| 00002a20 33 30 20 4f 4e 45 52 52 4f 52 20 47 4f 54 4f 20 |30 ONERROR GOTO | 00002a30 31 31 32 30 0d 20 31 30 34 30 20 50 52 49 4e 54 |1120. 1040 PRINT| 00002a40 54 41 42 28 31 30 2c 37 29 22 42 79 74 65 73 20 |TAB(10,7)"Bytes | 00002a50 75 73 65 64 20 3d 20 26 22 3b 7e 6c 61 73 74 62 |used = &";~lastb| 00002a60 79 74 65 2d 6d 63 6f 64 65 0d 20 31 30 35 30 20 |yte-mcode. 1050 | 00002a70 52 45 50 45 41 54 0d 20 31 30 36 30 20 50 52 49 |REPEAT. 1060 PRI| 00002a80 4e 54 54 41 42 28 31 30 2c 31 32 29 22 58 20 3d |NTTAB(10,12)"X =| 00002a90 20 26 22 3b 7e 3f 26 38 30 3b 22 20 22 54 41 42 | &";~?&80;" "TAB| 00002aa0 28 32 30 2c 31 32 29 3b 22 59 20 3d 20 26 22 3b |(20,12);"Y = &";| 00002ab0 7e 3f 26 38 31 3b 22 20 22 0d 20 31 30 37 30 20 |~?&81;" ". 1070 | 00002ac0 62 75 74 74 6f 6e 3d 3f 64 72 62 20 3a 52 45 4d |button=?drb :REM| 00002ad0 3a 20 64 61 74 61 20 72 65 67 69 73 74 65 72 20 |: data register | 00002ae0 42 0d 20 31 30 38 30 20 49 46 20 28 62 75 74 74 |B. 1080 IF (butt| 00002af0 6f 6e 20 41 4e 44 20 26 38 30 29 3d 30 20 50 52 |on AND &80)=0 PR| 00002b00 49 4e 54 54 41 42 28 32 32 2c 31 37 29 22 52 69 |INTTAB(22,17)"Ri| 00002b10 67 68 74 22 0d 20 20 20 20 20 20 45 4c 53 45 20 |ght". ELSE | 00002b20 50 52 49 4e 54 54 41 42 28 32 32 2c 31 37 29 22 |PRINTTAB(22,17)"| 00002b30 20 20 20 20 20 22 0d 20 31 30 39 30 20 49 46 20 | ". 1090 IF | 00002b40 28 62 75 74 74 6f 6e 20 41 4e 44 20 26 34 30 29 |(button AND &40)| 00002b50 3d 30 20 50 52 49 4e 54 54 41 42 28 31 35 2c 31 |=0 PRINTTAB(15,1| 00002b60 37 29 22 43 65 6e 74 72 65 22 0d 20 20 20 20 20 |7)"Centre". | 00002b70 20 45 4c 53 45 20 50 52 49 4e 54 54 41 42 28 31 | ELSE PRINTTAB(1| 00002b80 35 2c 31 37 29 22 20 20 20 20 20 20 22 0d 20 31 |5,17)" ". 1| 00002b90 31 30 30 20 49 46 20 28 62 75 74 74 6f 6e 20 41 |100 IF (button A| 00002ba0 4e 44 20 26 32 30 29 3d 30 20 50 52 49 4e 54 54 |ND &20)=0 PRINTT| 00002bb0 41 42 28 31 30 2c 31 37 29 22 4c 65 66 74 22 0d |AB(10,17)"Left".| 00002bc0 20 20 20 20 20 20 45 4c 53 45 20 50 52 49 4e 54 | ELSE PRINT| 00002bd0 54 41 42 28 31 30 2c 31 37 29 22 20 20 20 20 22 |TAB(10,17)" "| 00002be0 0d 20 31 31 31 30 20 55 4e 54 49 4c 20 46 41 4c |. 1110 UNTIL FAL| 00002bf0 53 45 0d 20 31 31 32 30 20 56 44 55 32 33 2c 31 |SE. 1120 VDU23,1| 00002c00 2c 31 3b 30 3b 30 3b 30 3b 0d 20 31 31 33 30 20 |,1;0;0;0;. 1130 | 00002c10 43 41 4c 4c 20 6d 63 6f 64 65 0d |CALL mcode.| 00002c1b
27-11-88/T\MOU01.m0
27-11-88/T\MOU01.m1
27-11-88/T\MOU01.m2
27-11-88/T\MOU01.m4
27-11-88/T\MOU01.m5
.