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F/M\CTUT1
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 » Personal collection » Acorn ADFS disks » Electron_User_Group » EUG_19.ADF |
| Filename: | F/M\CTUT1 |
| Read OK: | ✔ |
| File size: | 1043 bytes |
| Load address: | 6D206576 |
| Exec address: | 742D632F |
File contents
USING THE ASSEMBLER 2
~~~~~~~~~~~~~~~~~~~~~
By Richard Dimond
I hope my introductory article has encouraged some experimenting with the
assembler. How have you been getting on? Have you been able to find out
how to give the commands to change MODE and the colours and clear the
screen? These are all quite simple if you think of the VDU codes -
MODE <num> .mode LDA#22:JSR&FFEE:LDA#<num>:JSR&FFEE \VDU22,<num>
COLOUR<col> .colour LDA#17:JSR&FFEE:LDA#<col>:JSR&FFEE \VDU17,<col>
GCOL0,<col> .gcol LDA#18:JSR&FFEE:LDA#0:JSR&FFEE:LDA#<col>:JSR&FFEE
\VDU18,0,col
CLS .cls LDA#12:JSR&FFEE \VDU12
CLG .clg LDA#16:JSR&FFEE \VDU16
These could all be entered as subroutines and called with JSR<label>. If
a variable is to be entered, this can be done by LDX#<num> .... TXA ....
as in the 'tab' routine. Though, as they are short, it is best to enter
them in the main loop as required.
However, if you are entering a series of commands, a simpler method is to
use a loop - you will find loops used a lot in M/code, they are rather
like REPEAT/UNTIL loops in BASIC. As I said last time, the VDU codes can
be used with the 'print' rotine and instead of using 'tab', enter in the
data -
.text EQUB31:EQUB<x>:EQUB<y>:EQUS"<..TEXT.."+CHR$&FF
\VDU31,x,y:PRINT"..TEXT.."
If you think of MODE 5:COLOUR2:COLOUR129 as -
VDU22,5,17,2,17,129
Then enter the data -
.mode_col EQUB22:EQUB5:EQUB17:EQUB2:EQUB17:EQUB129:EQUB&FF
and use the 'print' routine as before.
While you can use the print routine in this way, it cannot be used if you
need the value 255 in the code. This can occur with PLOT routines which I
hope to cover next time. It is then necessary to use a different form of
loop. You need to return from the routine after the number of values have
been printed and this can be done comparing the value of Y register -
.comms STX &70
STY &71
LDY #0
.cloop LDA(&70),Y
JSR &FFEE
INY
CPY #<num> / num = no. of values
BNE cloop
RTS
The disadvantage of this method is that the value of 'num' needs to be
altered if the number of values is changed. It is easier to do this if it
done before the routine is called as in previous routines.
It is also better to load Y register with the number of values and to
decrement Y. The routine is then stopped when Y reaches zero. Alter the
routine to -
.comms STX &70
STY &71
TAY
.cloop LDA(&70),Y
JSR &FFEE
DEY
BNE cloop
RTS
This will need the values entered in reverse order as the addresses are
read in reverse. This routine is used by -
LDA #num
LDX #data MOD256
LDY #data DIV256
JMP comms
The cursor can be switched by using the BASIC values in this routine -
Cursor off - 23,1,0,0,0,0,0,0,0,0
on - 23,1,1,0,0,0,0,0,0,0
Entered as EQUB0:EQUB0:etc....(reverse order)..EQUB1:EQUB23
If the the cursor is to be turned on and off in the program, it is better
to use a subroutine -
.cur LDA#23
JSR&FFEE
LDA#1
JSR&FFEE
TXA
JSR&FFEE
LDX#7
.lp LDA#0
JSR&FFEE
DEX
BNElp
RTS
Then LDX#0 for cursor off or LDX#1 for cursor on before calling the
routine. If you add these lines at the beginning of this routine -
.curoff LDA#1:BNEc:.curon LDA#0:TAX:.c
you may simply use JSR curoff or JSR curon.
I hope that I have given you something more to think about and to try out.
I learnt through trying things out and by my mistakes!!
Next time I hope to give routines for PLOT, DRAW and for VDU23 characters.
00000000 0d 55 53 49 4e 47 20 54 48 45 20 41 53 53 45 4d |.USING THE ASSEM| 00000010 42 4c 45 52 20 32 0d 7e 7e 7e 7e 7e 7e 7e 7e 7e |BLER 2.~~~~~~~~~| 00000020 7e 7e 7e 7e 7e 7e 7e 7e 7e 7e 7e 7e 0d 42 79 20 |~~~~~~~~~~~~.By | 00000030 52 69 63 68 61 72 64 20 44 69 6d 6f 6e 64 0d 0d |Richard Dimond..| 00000040 49 20 68 6f 70 65 20 6d 79 20 69 6e 74 72 6f 64 |I hope my introd| 00000050 75 63 74 6f 72 79 20 61 72 74 69 63 6c 65 1a 20 |uctory article. | 00000060 68 61 73 20 65 6e 63 6f 75 72 61 67 65 64 20 73 |has encouraged s| 00000070 6f 6d 65 20 65 78 70 65 72 69 6d 65 6e 74 69 6e |ome experimentin| 00000080 67 20 77 69 74 68 20 74 68 65 0d 61 73 73 65 6d |g with the.assem| 00000090 62 6c 65 72 2e 20 20 48 6f 77 20 68 61 76 65 20 |bler. How have | 000000a0 79 6f 75 20 62 65 65 6e 20 67 65 74 74 69 6e 67 |you been getting| 000000b0 20 6f 6e 3f 20 20 48 61 76 65 20 79 6f 75 20 62 | on? Have you b| 000000c0 65 65 6e 20 20 61 62 6c 65 20 74 6f 20 66 69 6e |een able to fin| 000000d0 64 20 6f 75 74 0d 68 6f 77 20 74 6f 20 67 69 76 |d out.how to giv| 000000e0 65 20 74 68 65 20 63 6f 6d 6d 61 6e 64 73 1a 20 |e the commands. | 000000f0 74 6f 1a 20 63 68 61 6e 67 65 1a 20 4d 4f 44 45 |to. change. MODE| 00000100 1a 20 61 6e 64 1a 20 74 68 65 20 63 6f 6c 6f 75 |. and. the colou| 00000110 72 73 20 61 6e 64 20 63 6c 65 61 72 20 74 68 65 |rs and clear the| 00000120 0d 73 63 72 65 65 6e 3f 20 20 54 68 65 73 65 20 |.screen? These | 00000130 61 72 65 20 61 6c 6c 20 71 75 69 74 65 20 73 69 |are all quite si| 00000140 6d 70 6c 65 20 69 66 20 79 6f 75 20 74 68 69 6e |mple if you thin| 00000150 6b 20 6f 66 20 74 68 65 20 56 44 55 20 63 6f 64 |k of the VDU cod| 00000160 65 73 20 2d 0d 0d 20 20 4d 4f 44 45 20 3c 6e 75 |es -.. MODE <nu| 00000170 6d 3e 20 20 2e 6d 6f 64 65 20 4c 44 41 23 32 32 |m> .mode LDA#22| 00000180 3a 4a 53 52 26 46 46 45 45 3a 4c 44 41 23 3c 6e |:JSR&FFEE:LDA#<n| 00000190 75 6d 3e 3a 4a 53 52 26 46 46 45 45 20 20 20 20 |um>:JSR&FFEE | 000001a0 20 5c 56 44 55 32 32 2c 3c 6e 75 6d 3e 0d 20 20 | \VDU22,<num>. | 000001b0 43 4f 4c 4f 55 52 3c 63 6f 6c 3e 20 2e 63 6f 6c |COLOUR<col> .col| 000001c0 6f 75 72 20 4c 44 41 23 31 37 3a 4a 53 52 26 46 |our LDA#17:JSR&F| 000001d0 46 45 45 3a 4c 44 41 23 3c 63 6f 6c 3e 3a 4a 53 |FEE:LDA#<col>:JS| 000001e0 52 26 46 46 45 45 20 20 20 5c 56 44 55 31 37 2c |R&FFEE \VDU17,| 000001f0 3c 63 6f 6c 3e 0d 20 20 47 43 4f 4c 30 2c 3c 63 |<col>. GCOL0,<c| 00000200 6f 6c 3e 20 2e 67 63 6f 6c 20 4c 44 41 23 31 38 |ol> .gcol LDA#18| 00000210 3a 4a 53 52 26 46 46 45 45 3a 4c 44 41 23 30 3a |:JSR&FFEE:LDA#0:| 00000220 4a 53 52 26 46 46 45 45 3a 4c 44 41 23 3c 63 6f |JSR&FFEE:LDA#<co| 00000230 6c 3e 3a 4a 53 52 26 46 46 45 45 0d 20 20 20 20 |l>:JSR&FFEE. | 00000240 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | * 00000270 20 20 20 20 20 20 20 5c 56 44 55 31 38 2c 30 2c | \VDU18,0,| 00000280 63 6f 6c 0d 20 20 43 4c 53 20 20 20 20 20 20 20 |col. CLS | 00000290 20 20 2e 63 6c 73 20 20 4c 44 41 23 31 32 3a 4a | .cls LDA#12:J| 000002a0 53 52 26 46 46 45 45 20 20 20 20 20 20 20 20 20 |SR&FFEE | 000002b0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 5c | \| 000002c0 56 44 55 31 32 0d 20 20 43 4c 47 20 20 20 20 20 |VDU12. CLG | 000002d0 20 20 20 20 2e 63 6c 67 20 20 4c 44 41 23 31 36 | .clg LDA#16| 000002e0 3a 4a 53 52 26 46 46 45 45 20 20 20 20 20 20 20 |:JSR&FFEE | 000002f0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00000300 20 5c 56 44 55 31 36 0d 0d 54 68 65 73 65 20 63 | \VDU16..These c| 00000310 6f 75 6c 64 20 61 6c 6c 20 62 65 20 65 6e 74 65 |ould all be ente| 00000320 72 65 64 1a 20 61 73 20 73 75 62 72 6f 75 74 69 |red. as subrouti| 00000330 6e 65 73 20 61 6e 64 20 63 61 6c 6c 65 64 20 77 |nes and called w| 00000340 69 74 68 20 4a 53 52 3c 6c 61 62 65 6c 3e 2e 20 |ith JSR<label>. | 00000350 20 49 66 0d 61 20 76 61 72 69 61 62 6c 65 20 69 | If.a variable i| 00000360 73 20 74 6f 20 62 65 20 65 6e 74 65 72 65 64 2c |s to be entered,| 00000370 1a 20 74 68 69 73 1a 20 63 61 6e 20 62 65 20 64 |. this. can be d| 00000380 6f 6e 65 20 62 79 20 4c 44 58 23 3c 6e 75 6d 3e |one by LDX#<num>| 00000390 20 2e 2e 2e 2e 20 54 58 41 20 2e 2e 2e 2e 0d 61 | .... TXA .....a| 000003a0 73 20 69 6e 20 74 68 65 20 27 74 61 62 27 20 72 |s in the 'tab' r| 000003b0 6f 75 74 69 6e 65 2e 20 20 54 68 6f 75 67 68 2c |outine. Though,| 000003c0 20 61 73 20 74 68 65 79 1a 20 61 72 65 1a 20 73 | as they. are. s| 000003d0 68 6f 72 74 2c 20 69 74 20 69 73 20 62 65 73 74 |hort, it is best| 000003e0 20 74 6f 20 65 6e 74 65 72 0d 74 68 65 6d 20 69 | to enter.them i| 000003f0 6e 20 74 68 65 20 6d 61 69 6e 20 6c 6f 6f 70 20 |n the main loop | 00000400 61 73 20 72 65 71 75 69 72 65 64 2e 0d 0d 48 6f |as required...Ho| 00000410 77 65 76 65 72 2c 20 69 66 20 79 6f 75 20 61 72 |wever, if you ar| 00000420 65 20 65 6e 74 65 72 69 6e 67 20 61 20 73 65 72 |e entering a ser| 00000430 69 65 73 1a 20 6f 66 20 63 6f 6d 6d 61 6e 64 73 |ies. of commands| 00000440 2c 20 61 20 73 69 6d 70 6c 65 72 20 6d 65 74 68 |, a simpler meth| 00000450 6f 64 20 69 73 20 74 6f 0d 75 73 65 20 61 20 6c |od is to.use a l| 00000460 6f 6f 70 20 2d 20 79 6f 75 20 77 69 6c 6c 20 66 |oop - you will f| 00000470 69 6e 64 20 6c 6f 6f 70 73 1a 20 75 73 65 64 1a |ind loops. used.| 00000480 20 61 1a 20 6c 6f 74 1a 20 69 6e 20 4d 2f 63 6f | a. lot. in M/co| 00000490 64 65 2c 20 74 68 65 79 20 61 72 65 20 72 61 74 |de, they are rat| 000004a0 68 65 72 0d 6c 69 6b 65 20 52 45 50 45 41 54 2f |her.like REPEAT/| 000004b0 55 4e 54 49 4c 20 6c 6f 6f 70 73 20 69 6e 20 42 |UNTIL loops in B| 000004c0 41 53 49 43 2e 20 20 41 73 20 49 20 73 61 69 64 |ASIC. As I said| 000004d0 20 6c 61 73 74 20 74 69 6d 65 2c 20 74 68 65 20 | last time, the | 000004e0 56 44 55 1a 20 63 6f 64 65 73 20 63 61 6e 0d 62 |VDU. codes can.b| 000004f0 65 1a 20 75 73 65 64 20 77 69 74 68 20 74 68 65 |e. used with the| 00000500 20 27 70 72 69 6e 74 27 20 72 6f 74 69 6e 65 20 | 'print' rotine | 00000510 20 61 6e 64 20 69 6e 73 74 65 61 64 20 6f 66 20 | and instead of | 00000520 75 73 69 6e 67 20 27 74 61 62 27 2c 20 65 6e 74 |using 'tab', ent| 00000530 65 72 20 69 6e 20 74 68 65 0d 64 61 74 61 20 2d |er in the.data -| 00000540 0d 20 20 20 20 20 20 20 20 2e 74 65 78 74 20 45 |. .text E| 00000550 51 55 42 33 31 3a 45 51 55 42 3c 78 3e 3a 45 51 |QUB31:EQUB<x>:EQ| 00000560 55 42 3c 79 3e 3a 45 51 55 53 22 3c 2e 2e 54 45 |UB<y>:EQUS"<..TE| 00000570 58 54 2e 2e 22 2b 43 48 52 24 26 46 46 0d 20 20 |XT.."+CHR$&FF. | 00000580 20 20 20 20 20 20 20 20 20 5c 56 44 55 33 31 2c | \VDU31,| 00000590 78 2c 79 3a 50 52 49 4e 54 22 2e 2e 54 45 58 54 |x,y:PRINT"..TEXT| 000005a0 2e 2e 22 0d 0d 49 66 20 79 6f 75 20 74 68 69 6e |.."..If you thin| 000005b0 6b 20 6f 66 20 4d 4f 44 45 20 35 3a 43 4f 4c 4f |k of MODE 5:COLO| 000005c0 55 52 32 3a 43 4f 4c 4f 55 52 31 32 39 20 61 73 |UR2:COLOUR129 as| 000005d0 20 2d 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 | -. | 000005e0 20 20 20 56 44 55 32 32 2c 35 2c 31 37 2c 32 2c | VDU22,5,17,2,| 000005f0 31 37 2c 31 32 39 0d 0d 54 68 65 6e 20 65 6e 74 |17,129..Then ent| 00000600 65 72 20 74 68 65 20 64 61 74 61 20 2d 0d 20 20 |er the data -. | 00000610 20 20 20 20 20 20 20 2e 6d 6f 64 65 5f 63 6f 6c | .mode_col| 00000620 20 45 51 55 42 32 32 3a 45 51 55 42 35 3a 45 51 | EQUB22:EQUB5:EQ| 00000630 55 42 31 37 3a 45 51 55 42 32 3a 45 51 55 42 31 |UB17:EQUB2:EQUB1| 00000640 37 3a 45 51 55 42 31 32 39 3a 45 51 55 42 26 46 |7:EQUB129:EQUB&F| 00000650 46 0d 61 6e 64 20 75 73 65 20 74 68 65 20 27 70 |F.and use the 'p| 00000660 72 69 6e 74 27 20 72 6f 75 74 69 6e 65 20 61 73 |rint' routine as| 00000670 20 62 65 66 6f 72 65 2e 0d 0d 57 68 69 6c 65 20 | before...While | 00000680 79 6f 75 20 63 61 6e 20 75 73 65 20 74 68 65 20 |you can use the | 00000690 70 72 69 6e 74 20 72 6f 75 74 69 6e 65 1a 20 69 |print routine. i| 000006a0 6e 20 74 68 69 73 20 77 61 79 2c 20 69 74 20 63 |n this way, it c| 000006b0 61 6e 6e 6f 74 20 62 65 20 75 73 65 64 20 69 66 |annot be used if| 000006c0 20 79 6f 75 0d 6e 65 65 64 20 74 68 65 20 76 61 | you.need the va| 000006d0 6c 75 65 20 32 35 35 20 69 6e 20 74 68 65 20 63 |lue 255 in the c| 000006e0 6f 64 65 2e 20 20 54 68 69 73 20 63 61 6e 20 6f |ode. This can o| 000006f0 63 63 75 72 20 77 69 74 68 20 50 4c 4f 54 20 72 |ccur with PLOT r| 00000700 6f 75 74 69 6e 65 73 20 77 68 69 63 68 20 49 0d |outines which I.| 00000710 68 6f 70 65 20 74 6f 20 63 6f 76 65 72 20 6e 65 |hope to cover ne| 00000720 78 74 20 74 69 6d 65 2e 1a 20 20 49 74 20 69 73 |xt time.. It is| 00000730 20 74 68 65 6e 20 6e 65 63 65 73 73 61 72 79 20 | then necessary | 00000740 74 6f 20 75 73 65 20 61 20 64 69 66 66 65 72 65 |to use a differe| 00000750 6e 74 20 66 6f 72 6d 20 6f 66 0d 6c 6f 6f 70 2e |nt form of.loop.| 00000760 20 20 59 6f 75 20 6e 65 65 64 20 74 6f 20 72 65 | You need to re| 00000770 74 75 72 6e 20 66 72 6f 6d 20 74 68 65 20 72 6f |turn from the ro| 00000780 75 74 69 6e 65 20 61 66 74 65 72 20 74 68 65 20 |utine after the | 00000790 6e 75 6d 62 65 72 20 6f 66 20 76 61 6c 75 65 73 |number of values| 000007a0 20 68 61 76 65 0d 62 65 65 6e 20 70 72 69 6e 74 | have.been print| 000007b0 65 64 20 61 6e 64 20 74 68 69 73 20 63 61 6e 20 |ed and this can | 000007c0 62 65 20 64 6f 6e 65 20 63 6f 6d 70 61 72 69 6e |be done comparin| 000007d0 67 20 74 68 65 20 76 61 6c 75 65 20 6f 66 20 59 |g the value of Y| 000007e0 20 72 65 67 69 73 74 65 72 20 2d 0d 0d 20 20 20 | register -.. | 000007f0 20 20 20 20 2e 63 6f 6d 6d 73 20 20 20 53 54 58 | .comms STX| 00000800 20 26 37 30 0d 20 20 20 20 20 20 20 20 20 20 20 | &70. | 00000810 20 20 20 20 20 53 54 59 20 26 37 31 0d 20 20 20 | STY &71. | 00000820 20 20 20 20 20 20 20 20 20 20 20 20 20 4c 44 59 | LDY| 00000830 20 23 30 0d 20 20 20 20 20 20 20 2e 63 6c 6f 6f | #0. .cloo| 00000840 70 20 20 20 4c 44 41 28 26 37 30 29 2c 59 0d 20 |p LDA(&70),Y. | 00000850 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 4a | J| 00000860 53 52 20 26 46 46 45 45 0d 20 20 20 20 20 20 20 |SR &FFEE. | 00000870 20 20 20 20 20 20 20 20 20 49 4e 59 0d 20 20 20 | INY. | 00000880 20 20 20 20 20 20 20 20 20 20 20 20 20 43 50 59 | CPY| 00000890 20 23 3c 6e 75 6d 3e 20 20 20 20 2f 20 6e 75 6d | #<num> / num| 000008a0 20 3d 20 6e 6f 2e 20 6f 66 20 76 61 6c 75 65 73 | = no. of values| 000008b0 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |. | 000008c0 20 42 4e 45 20 63 6c 6f 6f 70 0d 20 20 20 20 20 | BNE cloop. | 000008d0 20 20 20 20 20 20 20 20 20 20 20 52 54 53 0d 0d | RTS..| 000008e0 54 68 65 1a 20 64 69 73 61 64 76 61 6e 74 61 67 |The. disadvantag| 000008f0 65 20 6f 66 20 74 68 69 73 20 6d 65 74 68 6f 64 |e of this method| 00000900 20 69 73 20 74 68 61 74 20 74 68 65 20 76 61 6c | is that the val| 00000910 75 65 20 6f 66 20 27 6e 75 6d 27 1a 20 6e 65 65 |ue of 'num'. nee| 00000920 64 73 1a 20 74 6f 1a 20 62 65 0d 61 6c 74 65 72 |ds. to. be.alter| 00000930 65 64 20 69 66 20 74 68 65 20 6e 75 6d 62 65 72 |ed if the number| 00000940 20 6f 66 20 76 61 6c 75 65 73 20 69 73 20 63 68 | of values is ch| 00000950 61 6e 67 65 64 2e 20 20 49 74 20 69 73 20 65 61 |anged. It is ea| 00000960 73 69 65 72 20 74 6f 20 64 6f 20 74 68 69 73 20 |sier to do this | 00000970 69 66 20 69 74 0d 64 6f 6e 65 20 62 65 66 6f 72 |if it.done befor| 00000980 65 20 74 68 65 20 72 6f 75 74 69 6e 65 20 69 73 |e the routine is| 00000990 20 63 61 6c 6c 65 64 20 61 73 20 69 6e 20 70 72 | called as in pr| 000009a0 65 76 69 6f 75 73 20 72 6f 75 74 69 6e 65 73 2e |evious routines.| 000009b0 0d 0d 49 74 20 69 73 1a 20 61 6c 73 6f 1a 20 62 |..It is. also. b| 000009c0 65 74 74 65 72 1a 20 74 6f 1a 20 6c 6f 61 64 1a |etter. to. load.| 000009d0 20 59 20 72 65 67 69 73 74 65 72 20 77 69 74 68 | Y register with| 000009e0 20 74 68 65 20 6e 75 6d 62 65 72 20 6f 66 20 76 | the number of v| 000009f0 61 6c 75 65 73 20 61 6e 64 20 74 6f 0d 64 65 63 |alues and to.dec| 00000a00 72 65 6d 65 6e 74 20 59 2e 20 20 54 68 65 20 72 |rement Y. The r| 00000a10 6f 75 74 69 6e 65 20 69 73 20 74 68 65 6e 20 73 |outine is then s| 00000a20 74 6f 70 70 65 64 1a 20 77 68 65 6e 20 59 20 72 |topped. when Y r| 00000a30 65 61 63 68 65 73 20 7a 65 72 6f 2e 20 20 41 6c |eaches zero. Al| 00000a40 74 65 72 20 74 68 65 0d 72 6f 75 74 69 6e 65 20 |ter the.routine | 00000a50 74 6f 20 2d 0d 20 20 0d 20 20 20 20 20 20 20 20 |to -. . | 00000a60 20 2e 63 6f 6d 6d 73 20 20 20 53 54 58 20 26 37 | .comms STX &7| 00000a70 30 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |0. | 00000a80 20 20 20 20 53 54 59 20 26 37 31 0d 20 20 20 20 | STY &71. | 00000a90 20 20 20 20 20 20 20 20 20 20 20 20 20 20 54 41 | TA| 00000aa0 59 0d 20 20 20 20 20 20 20 20 20 2e 63 6c 6f 6f |Y. .cloo| 00000ab0 70 20 20 20 4c 44 41 28 26 37 30 29 2c 59 0d 20 |p LDA(&70),Y. | 00000ac0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00000ad0 20 4a 53 52 20 26 46 46 45 45 0d 20 20 20 20 20 | JSR &FFEE. | 00000ae0 20 20 20 20 20 20 20 20 20 20 20 20 20 44 45 59 | DEY| 00000af0 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |. | 00000b00 20 20 20 42 4e 45 20 63 6c 6f 6f 70 0d 20 20 20 | BNE cloop. | 00000b10 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 52 | R| 00000b20 54 53 0d 0d 54 68 69 73 20 77 69 6c 6c 20 6e 65 |TS..This will ne| 00000b30 65 64 20 74 68 65 20 76 61 6c 75 65 73 20 65 6e |ed the values en| 00000b40 74 65 72 65 64 20 69 6e 20 72 65 76 65 72 73 65 |tered in reverse| 00000b50 1a 20 6f 72 64 65 72 1a 20 61 73 1a 20 74 68 65 |. order. as. the| 00000b60 20 61 64 64 72 65 73 73 65 73 20 61 72 65 0d 72 | addresses are.r| 00000b70 65 61 64 20 69 6e 20 72 65 76 65 72 73 65 2e 20 |ead in reverse. | 00000b80 20 54 68 69 73 20 72 6f 75 74 69 6e 65 20 69 73 | This routine is| 00000b90 20 75 73 65 64 20 62 79 20 2d 0d 0d 20 20 20 20 | used by -.. | 00000ba0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 4c 44 | LD| 00000bb0 41 20 23 6e 75 6d 0d 20 20 20 20 20 20 20 20 20 |A #num. | 00000bc0 20 20 20 20 20 20 20 20 20 4c 44 58 20 23 64 61 | LDX #da| 00000bd0 74 61 20 4d 4f 44 32 35 36 0d 20 20 20 20 20 20 |ta MOD256. | 00000be0 20 20 20 20 20 20 20 20 20 20 20 20 4c 44 59 20 | LDY | 00000bf0 23 64 61 74 61 20 44 49 56 32 35 36 0d 20 20 20 |#data DIV256. | 00000c00 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 4a | J| 00000c10 4d 50 20 63 6f 6d 6d 73 0d 0d 54 68 65 20 63 75 |MP comms..The cu| 00000c20 72 73 6f 72 20 63 61 6e 20 62 65 20 73 77 69 74 |rsor can be swit| 00000c30 63 68 65 64 20 62 79 20 75 73 69 6e 67 20 74 68 |ched by using th| 00000c40 65 20 42 41 53 49 43 20 76 61 6c 75 65 73 20 69 |e BASIC values i| 00000c50 6e 20 74 68 69 73 20 72 6f 75 74 69 6e 65 20 2d |n this routine -| 00000c60 0d 0d 20 20 20 20 43 75 72 73 6f 72 20 6f 66 66 |.. Cursor off| 00000c70 20 2d 20 32 33 2c 31 2c 30 2c 30 2c 30 2c 30 2c | - 23,1,0,0,0,0,| 00000c80 30 2c 30 2c 30 2c 30 20 20 0d 20 20 20 20 20 20 |0,0,0,0 . | 00000c90 20 20 20 20 20 6f 6e 20 20 2d 20 32 33 2c 31 2c | on - 23,1,| 00000ca0 31 2c 30 2c 30 2c 30 2c 30 2c 30 2c 30 2c 30 0d |1,0,0,0,0,0,0,0.| 00000cb0 0d 45 6e 74 65 72 65 64 20 61 73 20 45 51 55 42 |.Entered as EQUB| 00000cc0 30 3a 45 51 55 42 30 3a 65 74 63 2e 2e 2e 2e 28 |0:EQUB0:etc....(| 00000cd0 72 65 76 65 72 73 65 20 6f 72 64 65 72 29 2e 2e |reverse order)..| 00000ce0 45 51 55 42 31 3a 45 51 55 42 32 33 0d 0d 49 66 |EQUB1:EQUB23..If| 00000cf0 20 74 68 65 20 74 68 65 20 63 75 72 73 6f 72 1a | the the cursor.| 00000d00 20 69 73 20 74 6f 20 62 65 20 74 75 72 6e 65 64 | is to be turned| 00000d10 20 6f 6e 20 61 6e 64 20 6f 66 66 20 69 6e 20 74 | on and off in t| 00000d20 68 65 20 70 72 6f 67 72 61 6d 2c 20 69 74 20 69 |he program, it i| 00000d30 73 20 62 65 74 74 65 72 0d 74 6f 20 20 75 73 65 |s better.to use| 00000d40 20 61 20 73 75 62 72 6f 75 74 69 6e 65 20 2d 0d | a subroutine -.| 00000d50 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 2e 63 |. .c| 00000d60 75 72 20 20 4c 44 41 23 32 33 0d 20 20 20 20 20 |ur LDA#23. | 00000d70 20 20 20 20 20 20 20 20 20 20 20 20 20 20 4a 53 | JS| 00000d80 52 26 46 46 45 45 0d 20 20 20 20 20 20 20 20 20 |R&FFEE. | 00000d90 20 20 20 20 20 20 20 20 20 20 4c 44 41 23 31 0d | LDA#1.| 00000da0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00000db0 20 20 20 4a 53 52 26 46 46 45 45 0d 20 20 20 20 | JSR&FFEE. | 00000dc0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 54 | T| 00000dd0 58 41 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 |XA. | 00000de0 20 20 20 20 20 20 4a 53 52 26 46 46 45 45 0d 20 | JSR&FFEE. | 00000df0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00000e00 20 20 4c 44 58 23 37 0d 20 20 20 20 20 20 20 20 | LDX#7. | 00000e10 20 20 20 20 20 20 2e 6c 70 20 20 4c 44 41 23 30 | .lp LDA#0| 00000e20 0d 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |. | 00000e30 20 20 20 20 4a 53 52 26 46 46 45 45 0d 20 20 20 | JSR&FFEE. | 00000e40 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00000e50 44 45 58 0d 20 20 20 20 20 20 20 20 20 20 20 20 |DEX. | 00000e60 20 20 20 20 20 20 20 42 4e 45 6c 70 0d 20 20 20 | BNElp. | 00000e70 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | | 00000e80 52 54 53 0d 0d 54 68 65 6e 20 4c 44 58 23 30 20 |RTS..Then LDX#0 | 00000e90 66 6f 72 20 63 75 72 73 6f 72 20 6f 66 66 1a 20 |for cursor off. | 00000ea0 6f 72 1a 20 4c 44 58 23 31 1a 20 66 6f 72 1a 20 |or. LDX#1. for. | 00000eb0 63 75 72 73 6f 72 1a 20 6f 6e 1a 20 62 65 66 6f |cursor. on. befo| 00000ec0 72 65 1a 20 63 61 6c 6c 69 6e 67 20 74 68 65 0d |re. calling the.| 00000ed0 72 6f 75 74 69 6e 65 2e 20 49 66 20 79 6f 75 20 |routine. If you | 00000ee0 61 64 64 20 74 68 65 73 65 20 6c 69 6e 65 73 20 |add these lines | 00000ef0 61 74 20 74 68 65 20 62 65 67 69 6e 6e 69 6e 67 |at the beginning| 00000f00 20 6f 66 20 74 68 69 73 20 72 6f 75 74 69 6e 65 | of this routine| 00000f10 20 2d 0d 0d 20 20 20 20 20 20 20 20 2e 63 75 72 | -.. .cur| 00000f20 6f 66 66 20 4c 44 41 23 31 3a 42 4e 45 63 3a 2e |off LDA#1:BNEc:.| 00000f30 63 75 72 6f 6e 20 4c 44 41 23 30 3a 54 41 58 3a |curon LDA#0:TAX:| 00000f40 2e 63 0d 0d 79 6f 75 20 6d 61 79 20 73 69 6d 70 |.c..you may simp| 00000f50 6c 79 20 75 73 65 20 4a 53 52 20 63 75 72 6f 66 |ly use JSR curof| 00000f60 66 20 6f 72 20 4a 53 52 20 63 75 72 6f 6e 2e 0d |f or JSR curon..| 00000f70 0d 49 20 68 6f 70 65 20 74 68 61 74 20 49 20 68 |.I hope that I h| 00000f80 61 76 65 20 67 69 76 65 6e 20 79 6f 75 20 73 6f |ave given you so| 00000f90 6d 65 74 68 69 6e 67 20 6d 6f 72 65 20 74 6f 20 |mething more to | 00000fa0 74 68 69 6e 6b 20 61 62 6f 75 74 20 61 6e 64 20 |think about and | 00000fb0 74 6f 20 74 72 79 20 6f 75 74 2e 20 20 0d 49 20 |to try out. .I | 00000fc0 6c 65 61 72 6e 74 20 74 68 72 6f 75 67 68 20 74 |learnt through t| 00000fd0 72 79 69 6e 67 20 74 68 69 6e 67 73 20 6f 75 74 |rying things out| 00000fe0 20 61 6e 64 20 62 79 20 6d 79 20 6d 69 73 74 61 | and by my mista| 00000ff0 6b 65 73 21 21 0d 0d 4e 65 78 74 20 74 69 6d 65 |kes!!..Next time| 00001000 20 49 20 68 6f 70 65 20 74 6f 20 67 69 76 65 20 | I hope to give | 00001010 72 6f 75 74 69 6e 65 73 20 66 6f 72 20 50 4c 4f |routines for PLO| 00001020 54 2c 20 44 52 41 57 20 61 6e 64 20 66 6f 72 20 |T, DRAW and for | 00001030 56 44 55 32 33 20 63 68 61 72 61 63 74 65 72 73 |VDU23 characters| 00001040 2e 0d 0d |...| 00001043
F/M\CTUT1.m0
F/M\CTUT1.m1
F/M\CTUT1.m2
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