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27_11_87/T\SWR06
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 » telesoftware3.adl |
| Filename: | 27_11_87/T\SWR06 |
| Read OK: | ✔ |
| File size: | 2F6E bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
Duplicates
There is 1 duplicate copy of this file in the archive:
- CEEFAX disks » telesoftware3.adl » 27_11_87/T\SWR06
- CEEFAX disks » telesoftware8.adl » 13-08-88/T\SWR06
File contents
Mastering Sideways ROM & RAM - Module 06 - Osbyte
-------------------------------------------------
In Module 5 you were shown how to read an argument which follows a *
command. The argument is always read as an ASCII string. This is fine
if the string is a word such as "ON" or "OFF" but it can be a problem
if the argument is a number. The number must be read as an ASCII
string but it has to be converted into binary before the computer can
use it as a number. The computer can store a number in the range from
&00 to &FF in one byte. In order to read just one byte as an argument
up to three ASCII characters representing the byte have to be read,
converted into binary and stored in a byte of user memory.
You have two options if you want to read numerical arguments.
1. Write a routine to read every ASCII character in the argument and
convert the ASCII representation of the number into binary.
2. Use the MOS to do the work for you.
The first option, not surprisingly, involves more work than the
second. If you write your own conversion routine it has to include
error handling and a check for validity. It also has to have somewhere
in memory to store the result. This will be covered in detail in
Module 9.
The second option involves defining a new Osbyte or Osword. Osbyte
will be covered in this module and Osword in Module 7.
Osbyte is an MOS call specified by the contents of the accumulator
taking parameters in the X and Y registers. Osbyte calls 22 (&15) to
116 (&74) are not used by MOS 1.20 and can be defined within your SWR
programs. Other operating systems use some of these unused Osbyte
calls. For example *FX 114 is used to switch shadow screen memory on
and off in the B+ and Master computers. You can use TRACE to check if
any particular Osbyte call is unused by your operating system. *FX 100
is not used by any operating system (as far as I know) and will be
used in the example program for this module.
Load the object code generated by TRACE into SWR and press the Break
key. Type *FX 100 and press Return. You will see that service call 7
is used for an unrecognised Osbyte. Type *FX 100,1,1 and you will see
that the Osbyte X and Y parameters are not made available to the
interpreter in the X and Y registers as you might expect. Figure 6.1
shows that, whatever value you type for the Osbyte X and Y parameters,
the rom is entered with X storing the rom number and Y storing zero.
>*FX 100
A=07 X=0F Y=00 Unrecognised Osbyte
>*FX 100,1,1
A=07 X=0F Y=00 Unrecognised Osbyte
>*FX 100,100,100
A=07 X=0F Y=00 Unrecognised Osbyte
>
Figure 6.1 Service trace for unrecognised Osbyte.
-------------------------------------------------
Osbyte uses three consecutive bytes in zero page to store the values
of the A, X and Y registers. The accumulator value for the most recent
Osbyte (or Osword) is stored in &EF. The X register value is stored in
&F0 and the Y register value is stored in &F1. Both Osbyte and Osword
make the three registers available to the routine through these three
zero page locations.
After processing an Osbyte call any values that need to be returned
to the calling routine should be stored in locations &F0 and &F1. On
return the number stored in the X register and &F0 should be the same
and the number stored in the Y register and &F1 should be the same.
&EF should store the number of your new Osbyte and the accumulator
should be reset to zero before returning to the MOS. On return to the
MOS the number stored in &EF is copied into the accumulator.
You can use the X and Y parameters of an Osbyte call to make two
(one byte) numbers or one (two byte) number available to your new
routine. If you want to make a two byte number available store the
least significant byte in X and the most significant byte in Y. For
example,
LDA #100 \ New osbyte
LDX #(number MOD 256) \ Least significant byte
LDY #(number DIV 256) \ Most significant byte
JSR &FFF4 \ Call osbyte
Your new Osbyte can then read the least significant byte fron &F0
and the most significant byte from &F1. It can also use these memory
locations for post-indexed indirect addressing.
The interpreter needed to implement a new Osbyte is probably the
easiest of all interpreters to write. An outline interpreter is shown
in figure 6.2.
.service
PHA \ push accumulator
CMP #7 \ is it an unrecognised Osbyte?
BEQ newosbyte \ branch if it is
.exit
PLA \ pull accumulator
RTS \ return and give other roms the call
.newosbyte
LDA &EF \ load Osbyte number from &EF
CMP #100 \ is it 100?
BNE exit \ branch if not Osbyte 100
LDX &F0 \ read X from &F0
LDY &F1 \ read Y from &F1
.
. \ new routine goes in here
.
STX &F0 \ store result for X
STY &F1 \ store result for Y
PLA \ pull A pushed by interpreter
LDA #0 \ other roms ignore this call
RTS \ return to MOS
Figure 6.2 An Osbyte interpreter.
---------------------------------
The service entry point of the outline interpreter in figure 6.2
will have a jump to the label ".service". On entering the interpreter
the accumulator is pushed on the stack and then compared with 7 to see
if the call is an unrecognised Osbyte. If it is not the accumulator is
pulled off the stack and control is returned to the MOS. If the call
is for an unrecognised Osbyte the number stored in &EF is loaded into
the accumulator and compared with the number of the new Osbyte, in
this example 100.
If the unrecognised Osbyte number stored in &EF is not 100 the
accumulator is pulled off the stack and control is returned to the
MOS. If it is 100 then the parameters (if used) can be read from &F0
(X register) and &F1 (Y register) and the new routine can be executed.
After completing the new routine any results are stored in &F0 (X
register) and &F1 (Y register). The index registers and their zero
page copies should be identical. Even if you don't want to write any
results you should still ensure that the index registers are identical
to their zero page copies. The accumulator was pushed on the stack by
the interpreter and it is pulled back off to balance the stack. The
accumulator is reset to zero to inform other roms that the service
call has been recognised and control is passed back to the MOS.
The interpreter in figure 6.2 is used in the example program OSBYTE.
This program generates the object code for *FX 100,x,y in which the X
parameter is the number of a rom to be disabled and the Y parameter is
used as a flag which, if set, tells the routine to print a list of the
active roms. If the X parameter is outside the range from 0 to 15 it
is ignored. To use the program load the object code it generates into
SWR and press the Break key. You can use the new Osbyte to disable any
rom, except BASIC, until the Break key is pressed to re-enable it.
Type *FX 100,100,1 to list the roms in your computer. This command
will be recognised as the new Osbyte but the X parameter is out of
range and it will not disable any rom. The Y parameter has a value
other than zero and the active roms will be listed.
Type *FX 100,10 to disable rom &0A without listing the active roms.
The Y parameter is not specified and takes the default value of zero.
Type *FX 100,8,1 to disable rom &08 and list the active roms.
You can re-enable all the roms disabled with this new Osbyte by
pressing the Break key.
The program uses an Osbyte interpreter (lines 310-410) similar to
the one outlined in figure 6.2. After recognising the new Osbyte
(lines 390-410) the new routine loads the X register with the X
parameter (line 420) and compares it with &10 (line 430) to see if it
is in the range from 0 to 15. If X is in range it disables the rom by
storing a zero in the rom information table byte that corresponds with
that rom (lines 450-460). The Y parameter is then loaded into the Y
register (line 480) and checked to see if it has been set (line 490).
If it has been set the active roms are listed (line 510).
The routine does not write any results to the zero page copies of
the index registers but it still ensures that the index registers and
their copies are identical (lines 530-540). The accumulator was pushed
on the stack by the interpreter (line 320) and it is pulled back off
in line 550. It is reset to zero to inform the other roms that the
service call has been recognised (line 560) and control is returned to
the MOS (line 570).
The subroutine romnames (lines 580-940) uses Osrdrm to list the
titles of the active roms and is similar to the routine used to print
rom titles in the program READROM (used in Module 1). The subroutine
decimal (lines 950-1110) prints the ASCII decimal equivalent of any
byte storing a number in the range from 0 to 99 (decimal). It is quite
a useful routine and can also be used to print a binary coded decimal
byte.
10 REM: OSBYTE
20 MODE7
30 HIMEM=&3C00
40 DIM save 50
50 diff=&8000-HIMEM
60 accumulator=&EF
70 xregister=&F0
80 yregister=&F1
90 rompoint=&F6
100 table=&2A1
110 osrdrm=&FFB9
120 osasci=&FFE3
130 osnewl=&FFE7
140 osbyte=&FFF4
150 oscli=&FFF7
160 FOR pass = 0 TO 2 STEP 2
170 P%=HIMEM
180 [ OPT pass
190 BRK
200 BRK
210 BRK
220 JMP service+diff
230 OPT FNequb(&82)
240 OPT FNequb((copyright+diff) MOD 256)
250 BRK
260 OPT FNequs("OSBYTE")
270 .copyright
280 BRK
290 OPT FNequs("(C) Gordon Horsington 1987")
300 BRK
310 .service
320 PHA
330 CMP #7
340 BEQ newosbyte
350 .exit
360 PLA
370 RTS
380 .newosbyte
390 LDA accumulator
400 CMP #100
410 BNE exit
420 LDX xregister
430 CPX #&10
440 BCS checkyreg
450 LDA #0
460 STA table,X
470 .checkyreg
480 LDY yregister
490 BEQ out
500 .romlist
510 JSR romnames+diff
520 .out
530 LDX xregister
540 LDY yregister
550 PLA
560 LDA #0
570 RTS
580 .romnames
590 JSR osnewl
600 LDA #&F
610 PHA
620 .romloop
630 TAY
640 LDA table,Y
650 BEQ nothere
660 TYA
670 JSR decimal+diff
680 LDA #ASC(" ")
690 JSR osasci
700 LDA #&8
710 STA rompoint
720 LDA #&80
730 STA rompoint+1
740 .readloop
750 INC rompoint
760 BEQ newline
770 PLA
780 PHA
790 TAY
800 JSR osrdrm
810 CMP #ASC(" ")
820 BCC newline
830 JSR osasci
840 JMP readloop+diff
850 .newline
860 JSR osnewl
870 .nothere
880 PLA
890 SEC
900 SBC #1
910 PHA
920 BPL romloop
930 PLA
940 JMP osnewl
950 .decimal
960 SED
970 CLC
980 ADC #0
990 CLD
1000 PHA
1010 LSR A
1020 LSR A
1030 LSR A
1040 LSR A
1050 JSR nibble+diff
1060 PLA
1070 AND #&F
1080 .nibble
1090 CLC
1100 ADC #ASC("0")
1110 JMP osasci
1120 .lastbyte
1130 ]
1140 NEXT
1150 INPUT'"Save filename = "filename$
1160 IF filename$="" END
1170 $save="SAVE "+filename$+" "+STR$~(HIMEM)+" "+STR$~(las
tbyte)+" FFFF8000 FFFF8000"
1180 X%=save MOD 256
1190 Y%=save DIV 256
1200 *OPT1,2
1210 CALL oscli
1220 *OPT1,0
1230 END
1240 DEFFNequb(byte)
1250 ?P%=byte
1260 P%=P%+1
1270 =pass
1280 DEFFNequw(word)
1290 ?P%=word MOD 256
1300 P%?1=word DIV 256
1310 P%=P%+2
1320 =pass
1330 DEFFNequd(double)
1340 !P%=double
1350 P%=P%+4
1360 =pass
1370 DEFFNequs(string$)
1380 $P%=string$
1390 P%=P%+LEN(string$)
1400 =pass
00000000 4d 61 73 74 65 72 69 6e 67 20 53 69 64 65 77 61 |Mastering Sidewa|
00000010 79 73 20 52 4f 4d 20 26 20 52 41 4d 20 2d 20 4d |ys ROM & RAM - M|
00000020 6f 64 75 6c 65 20 30 36 20 2d 20 4f 73 62 79 74 |odule 06 - Osbyt|
00000030 65 0d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |e.--------------|
00000040 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------|
*
00000060 2d 2d 2d 0d 0d 20 20 49 6e 20 4d 6f 64 75 6c 65 |---.. In Module|
00000070 20 35 20 79 6f 75 20 77 65 72 65 20 73 68 6f 77 | 5 you were show|
00000080 6e 20 68 6f 77 20 74 6f 20 72 65 61 64 20 61 6e |n how to read an|
00000090 20 61 72 67 75 6d 65 6e 74 20 77 68 69 63 68 20 | argument which |
000000a0 66 6f 6c 6c 6f 77 73 20 61 20 2a 0d 63 6f 6d 6d |follows a *.comm|
000000b0 61 6e 64 2e 20 54 68 65 20 61 72 67 75 6d 65 6e |and. The argumen|
000000c0 74 20 69 73 20 61 6c 77 61 79 73 20 72 65 61 64 |t is always read|
000000d0 20 61 73 20 61 6e 20 41 53 43 49 49 20 73 74 72 | as an ASCII str|
000000e0 69 6e 67 2e 20 54 68 69 73 20 69 73 20 66 69 6e |ing. This is fin|
000000f0 65 0d 69 66 20 74 68 65 20 73 74 72 69 6e 67 20 |e.if the string |
00000100 69 73 20 61 20 77 6f 72 64 20 73 75 63 68 20 61 |is a word such a|
00000110 73 20 22 4f 4e 22 20 6f 72 20 22 4f 46 46 22 20 |s "ON" or "OFF" |
00000120 62 75 74 20 69 74 20 63 61 6e 20 62 65 20 61 20 |but it can be a |
00000130 70 72 6f 62 6c 65 6d 0d 69 66 20 74 68 65 20 61 |problem.if the a|
00000140 72 67 75 6d 65 6e 74 20 69 73 20 61 20 6e 75 6d |rgument is a num|
00000150 62 65 72 2e 20 54 68 65 20 6e 75 6d 62 65 72 20 |ber. The number |
00000160 6d 75 73 74 20 62 65 20 72 65 61 64 20 61 73 20 |must be read as |
00000170 61 6e 20 41 53 43 49 49 0d 73 74 72 69 6e 67 20 |an ASCII.string |
00000180 62 75 74 20 69 74 20 68 61 73 20 74 6f 20 62 65 |but it has to be|
00000190 20 63 6f 6e 76 65 72 74 65 64 20 69 6e 74 6f 20 | converted into |
000001a0 62 69 6e 61 72 79 20 62 65 66 6f 72 65 20 74 68 |binary before th|
000001b0 65 20 63 6f 6d 70 75 74 65 72 20 63 61 6e 0d 75 |e computer can.u|
000001c0 73 65 20 69 74 20 61 73 20 61 20 6e 75 6d 62 65 |se it as a numbe|
000001d0 72 2e 20 54 68 65 20 63 6f 6d 70 75 74 65 72 20 |r. The computer |
000001e0 63 61 6e 20 73 74 6f 72 65 20 61 20 6e 75 6d 62 |can store a numb|
000001f0 65 72 20 69 6e 20 74 68 65 20 72 61 6e 67 65 20 |er in the range |
00000200 66 72 6f 6d 0d 26 30 30 20 74 6f 20 26 46 46 20 |from.&00 to &FF |
00000210 69 6e 20 6f 6e 65 20 62 79 74 65 2e 20 49 6e 20 |in one byte. In |
00000220 6f 72 64 65 72 20 74 6f 20 72 65 61 64 20 6a 75 |order to read ju|
00000230 73 74 20 6f 6e 65 20 62 79 74 65 20 61 73 20 61 |st one byte as a|
00000240 6e 20 61 72 67 75 6d 65 6e 74 0d 75 70 20 74 6f |n argument.up to|
00000250 20 74 68 72 65 65 20 41 53 43 49 49 20 63 68 61 | three ASCII cha|
00000260 72 61 63 74 65 72 73 20 72 65 70 72 65 73 65 6e |racters represen|
00000270 74 69 6e 67 20 74 68 65 20 62 79 74 65 20 68 61 |ting the byte ha|
00000280 76 65 20 74 6f 20 62 65 20 72 65 61 64 2c 0d 63 |ve to be read,.c|
00000290 6f 6e 76 65 72 74 65 64 20 69 6e 74 6f 20 62 69 |onverted into bi|
000002a0 6e 61 72 79 20 61 6e 64 20 73 74 6f 72 65 64 20 |nary and stored |
000002b0 69 6e 20 61 20 62 79 74 65 20 6f 66 20 75 73 65 |in a byte of use|
000002c0 72 20 6d 65 6d 6f 72 79 2e 0d 0d 20 20 59 6f 75 |r memory... You|
000002d0 20 68 61 76 65 20 74 77 6f 20 6f 70 74 69 6f 6e | have two option|
000002e0 73 20 69 66 20 79 6f 75 20 77 61 6e 74 20 74 6f |s if you want to|
000002f0 20 72 65 61 64 20 6e 75 6d 65 72 69 63 61 6c 20 | read numerical |
00000300 61 72 67 75 6d 65 6e 74 73 2e 0d 0d 31 2e 20 57 |arguments...1. W|
00000310 72 69 74 65 20 61 20 72 6f 75 74 69 6e 65 20 74 |rite a routine t|
00000320 6f 20 72 65 61 64 20 65 76 65 72 79 20 41 53 43 |o read every ASC|
00000330 49 49 20 63 68 61 72 61 63 74 65 72 20 69 6e 20 |II character in |
00000340 74 68 65 20 61 72 67 75 6d 65 6e 74 20 61 6e 64 |the argument and|
00000350 0d 63 6f 6e 76 65 72 74 20 74 68 65 20 41 53 43 |.convert the ASC|
00000360 49 49 20 72 65 70 72 65 73 65 6e 74 61 74 69 6f |II representatio|
00000370 6e 20 6f 66 20 74 68 65 20 6e 75 6d 62 65 72 20 |n of the number |
00000380 69 6e 74 6f 20 62 69 6e 61 72 79 2e 0d 0d 32 2e |into binary...2.|
00000390 20 55 73 65 20 74 68 65 20 4d 4f 53 20 74 6f 20 | Use the MOS to |
000003a0 64 6f 20 74 68 65 20 77 6f 72 6b 20 66 6f 72 20 |do the work for |
000003b0 79 6f 75 2e 0d 0d 20 20 54 68 65 20 66 69 72 73 |you... The firs|
000003c0 74 20 6f 70 74 69 6f 6e 2c 20 6e 6f 74 20 73 75 |t option, not su|
000003d0 72 70 72 69 73 69 6e 67 6c 79 2c 20 69 6e 76 6f |rprisingly, invo|
000003e0 6c 76 65 73 20 6d 6f 72 65 20 77 6f 72 6b 20 74 |lves more work t|
000003f0 68 61 6e 20 74 68 65 0d 73 65 63 6f 6e 64 2e 20 |han the.second. |
00000400 49 66 20 79 6f 75 20 77 72 69 74 65 20 79 6f 75 |If you write you|
00000410 72 20 6f 77 6e 20 63 6f 6e 76 65 72 73 69 6f 6e |r own conversion|
00000420 20 72 6f 75 74 69 6e 65 20 69 74 20 68 61 73 20 | routine it has |
00000430 74 6f 20 69 6e 63 6c 75 64 65 0d 65 72 72 6f 72 |to include.error|
00000440 20 68 61 6e 64 6c 69 6e 67 20 61 6e 64 20 61 20 | handling and a |
00000450 63 68 65 63 6b 20 66 6f 72 20 76 61 6c 69 64 69 |check for validi|
00000460 74 79 2e 20 49 74 20 61 6c 73 6f 20 68 61 73 20 |ty. It also has |
00000470 74 6f 20 68 61 76 65 20 73 6f 6d 65 77 68 65 72 |to have somewher|
00000480 65 0d 69 6e 20 6d 65 6d 6f 72 79 20 74 6f 20 73 |e.in memory to s|
00000490 74 6f 72 65 20 74 68 65 20 72 65 73 75 6c 74 2e |tore the result.|
000004a0 20 54 68 69 73 20 77 69 6c 6c 20 62 65 20 63 6f | This will be co|
000004b0 76 65 72 65 64 20 69 6e 20 64 65 74 61 69 6c 20 |vered in detail |
000004c0 69 6e 0d 4d 6f 64 75 6c 65 20 39 2e 0d 0d 20 20 |in.Module 9... |
000004d0 54 68 65 20 73 65 63 6f 6e 64 20 6f 70 74 69 6f |The second optio|
000004e0 6e 20 69 6e 76 6f 6c 76 65 73 20 64 65 66 69 6e |n involves defin|
000004f0 69 6e 67 20 61 20 6e 65 77 20 4f 73 62 79 74 65 |ing a new Osbyte|
00000500 20 6f 72 20 4f 73 77 6f 72 64 2e 20 4f 73 62 79 | or Osword. Osby|
00000510 74 65 0d 77 69 6c 6c 20 62 65 20 63 6f 76 65 72 |te.will be cover|
00000520 65 64 20 69 6e 20 74 68 69 73 20 6d 6f 64 75 6c |ed in this modul|
00000530 65 20 61 6e 64 20 4f 73 77 6f 72 64 20 69 6e 20 |e and Osword in |
00000540 4d 6f 64 75 6c 65 20 37 2e 0d 0d 20 20 4f 73 62 |Module 7... Osb|
00000550 79 74 65 20 69 73 20 61 6e 20 4d 4f 53 20 63 61 |yte is an MOS ca|
00000560 6c 6c 20 73 70 65 63 69 66 69 65 64 20 62 79 20 |ll specified by |
00000570 74 68 65 20 63 6f 6e 74 65 6e 74 73 20 6f 66 20 |the contents of |
00000580 74 68 65 20 61 63 63 75 6d 75 6c 61 74 6f 72 0d |the accumulator.|
00000590 74 61 6b 69 6e 67 20 70 61 72 61 6d 65 74 65 72 |taking parameter|
000005a0 73 20 69 6e 20 74 68 65 20 58 20 61 6e 64 20 59 |s in the X and Y|
000005b0 20 72 65 67 69 73 74 65 72 73 2e 20 4f 73 62 79 | registers. Osby|
000005c0 74 65 20 63 61 6c 6c 73 20 32 32 20 28 26 31 35 |te calls 22 (&15|
000005d0 29 20 74 6f 0d 31 31 36 20 28 26 37 34 29 20 61 |) to.116 (&74) a|
000005e0 72 65 20 6e 6f 74 20 75 73 65 64 20 62 79 20 4d |re not used by M|
000005f0 4f 53 20 31 2e 32 30 20 61 6e 64 20 63 61 6e 20 |OS 1.20 and can |
00000600 62 65 20 64 65 66 69 6e 65 64 20 77 69 74 68 69 |be defined withi|
00000610 6e 20 79 6f 75 72 20 53 57 52 0d 70 72 6f 67 72 |n your SWR.progr|
00000620 61 6d 73 2e 20 4f 74 68 65 72 20 6f 70 65 72 61 |ams. Other opera|
00000630 74 69 6e 67 20 73 79 73 74 65 6d 73 20 75 73 65 |ting systems use|
00000640 20 73 6f 6d 65 20 6f 66 20 74 68 65 73 65 20 75 | some of these u|
00000650 6e 75 73 65 64 20 4f 73 62 79 74 65 0d 63 61 6c |nused Osbyte.cal|
00000660 6c 73 2e 20 46 6f 72 20 65 78 61 6d 70 6c 65 20 |ls. For example |
00000670 2a 46 58 20 31 31 34 20 69 73 20 75 73 65 64 20 |*FX 114 is used |
00000680 74 6f 20 73 77 69 74 63 68 20 73 68 61 64 6f 77 |to switch shadow|
00000690 20 73 63 72 65 65 6e 20 6d 65 6d 6f 72 79 20 6f | screen memory o|
000006a0 6e 0d 61 6e 64 20 6f 66 66 20 69 6e 20 74 68 65 |n.and off in the|
000006b0 20 42 2b 20 61 6e 64 20 4d 61 73 74 65 72 20 63 | B+ and Master c|
000006c0 6f 6d 70 75 74 65 72 73 2e 20 59 6f 75 20 63 61 |omputers. You ca|
000006d0 6e 20 75 73 65 20 54 52 41 43 45 20 74 6f 20 63 |n use TRACE to c|
000006e0 68 65 63 6b 20 69 66 0d 61 6e 79 20 70 61 72 74 |heck if.any part|
000006f0 69 63 75 6c 61 72 20 4f 73 62 79 74 65 20 63 61 |icular Osbyte ca|
00000700 6c 6c 20 69 73 20 75 6e 75 73 65 64 20 62 79 20 |ll is unused by |
00000710 79 6f 75 72 20 6f 70 65 72 61 74 69 6e 67 20 73 |your operating s|
00000720 79 73 74 65 6d 2e 20 2a 46 58 20 31 30 30 0d 69 |ystem. *FX 100.i|
00000730 73 20 6e 6f 74 20 75 73 65 64 20 62 79 20 61 6e |s not used by an|
00000740 79 20 6f 70 65 72 61 74 69 6e 67 20 73 79 73 74 |y operating syst|
00000750 65 6d 20 28 61 73 20 66 61 72 20 61 73 20 49 20 |em (as far as I |
00000760 6b 6e 6f 77 29 20 61 6e 64 20 77 69 6c 6c 20 62 |know) and will b|
00000770 65 0d 75 73 65 64 20 69 6e 20 74 68 65 20 65 78 |e.used in the ex|
00000780 61 6d 70 6c 65 20 70 72 6f 67 72 61 6d 20 66 6f |ample program fo|
00000790 72 20 74 68 69 73 20 6d 6f 64 75 6c 65 2e 0d 0d |r this module...|
000007a0 20 20 4c 6f 61 64 20 74 68 65 20 6f 62 6a 65 63 | Load the objec|
000007b0 74 20 63 6f 64 65 20 67 65 6e 65 72 61 74 65 64 |t code generated|
000007c0 20 62 79 20 54 52 41 43 45 20 69 6e 74 6f 20 53 | by TRACE into S|
000007d0 57 52 20 61 6e 64 20 70 72 65 73 73 20 74 68 65 |WR and press the|
000007e0 20 42 72 65 61 6b 0d 6b 65 79 2e 20 54 79 70 65 | Break.key. Type|
000007f0 20 2a 46 58 20 31 30 30 20 61 6e 64 20 70 72 65 | *FX 100 and pre|
00000800 73 73 20 52 65 74 75 72 6e 2e 20 59 6f 75 20 77 |ss Return. You w|
00000810 69 6c 6c 20 73 65 65 20 74 68 61 74 20 73 65 72 |ill see that ser|
00000820 76 69 63 65 20 63 61 6c 6c 20 37 0d 69 73 20 75 |vice call 7.is u|
00000830 73 65 64 20 66 6f 72 20 61 6e 20 75 6e 72 65 63 |sed for an unrec|
00000840 6f 67 6e 69 73 65 64 20 4f 73 62 79 74 65 2e 20 |ognised Osbyte. |
00000850 54 79 70 65 20 2a 46 58 20 31 30 30 2c 31 2c 31 |Type *FX 100,1,1|
00000860 20 61 6e 64 20 79 6f 75 20 77 69 6c 6c 20 73 65 | and you will se|
00000870 65 0d 74 68 61 74 20 74 68 65 20 4f 73 62 79 74 |e.that the Osbyt|
00000880 65 20 58 20 61 6e 64 20 59 20 70 61 72 61 6d 65 |e X and Y parame|
00000890 74 65 72 73 20 61 72 65 20 6e 6f 74 20 6d 61 64 |ters are not mad|
000008a0 65 20 61 76 61 69 6c 61 62 6c 65 20 74 6f 20 74 |e available to t|
000008b0 68 65 0d 69 6e 74 65 72 70 72 65 74 65 72 20 69 |he.interpreter i|
000008c0 6e 20 74 68 65 20 58 20 61 6e 64 20 59 20 72 65 |n the X and Y re|
000008d0 67 69 73 74 65 72 73 20 61 73 20 79 6f 75 20 6d |gisters as you m|
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00002a10 20 20 20 49 4e 43 20 72 6f 6d 70 6f 69 6e 74 0d | INC rompoint.|
00002a20 20 20 37 36 30 20 20 20 20 20 20 20 20 20 42 45 | 760 BE|
00002a30 51 20 6e 65 77 6c 69 6e 65 0d 20 20 37 37 30 20 |Q newline. 770 |
00002a40 20 20 20 20 20 20 20 20 50 4c 41 0d 20 20 37 38 | PLA. 78|
00002a50 30 20 20 20 20 20 20 20 20 20 50 48 41 0d 20 20 |0 PHA. |
00002a60 37 39 30 20 20 20 20 20 20 20 20 20 54 41 59 0d |790 TAY.|
00002a70 20 20 38 30 30 20 20 20 20 20 20 20 20 20 4a 53 | 800 JS|
00002a80 52 20 6f 73 72 64 72 6d 0d 20 20 38 31 30 20 20 |R osrdrm. 810 |
00002a90 20 20 20 20 20 20 20 43 4d 50 20 23 41 53 43 28 | CMP #ASC(|
00002aa0 22 20 22 29 0d 20 20 38 32 30 20 20 20 20 20 20 |" "). 820 |
00002ab0 20 20 20 42 43 43 20 6e 65 77 6c 69 6e 65 0d 20 | BCC newline. |
00002ac0 20 38 33 30 20 20 20 20 20 20 20 20 20 4a 53 52 | 830 JSR|
00002ad0 20 6f 73 61 73 63 69 0d 20 20 38 34 30 20 20 20 | osasci. 840 |
00002ae0 20 20 20 20 20 20 4a 4d 50 20 72 65 61 64 6c 6f | JMP readlo|
00002af0 6f 70 2b 64 69 66 66 0d 20 20 38 35 30 20 2e 6e |op+diff. 850 .n|
00002b00 65 77 6c 69 6e 65 0d 20 20 38 36 30 20 20 20 20 |ewline. 860 |
00002b10 20 20 20 20 20 4a 53 52 20 6f 73 6e 65 77 6c 0d | JSR osnewl.|
00002b20 20 20 38 37 30 20 2e 6e 6f 74 68 65 72 65 0d 20 | 870 .nothere. |
00002b30 20 38 38 30 20 20 20 20 20 20 20 20 20 50 4c 41 | 880 PLA|
00002b40 0d 20 20 38 39 30 20 20 20 20 20 20 20 20 20 53 |. 890 S|
00002b50 45 43 0d 20 20 39 30 30 20 20 20 20 20 20 20 20 |EC. 900 |
00002b60 20 53 42 43 20 23 31 0d 20 20 39 31 30 20 20 20 | SBC #1. 910 |
00002b70 20 20 20 20 20 20 50 48 41 0d 20 20 39 32 30 20 | PHA. 920 |
00002b80 20 20 20 20 20 20 20 20 42 50 4c 20 72 6f 6d 6c | BPL roml|
00002b90 6f 6f 70 0d 20 20 39 33 30 20 20 20 20 20 20 20 |oop. 930 |
00002ba0 20 20 50 4c 41 0d 20 20 39 34 30 20 20 20 20 20 | PLA. 940 |
00002bb0 20 20 20 20 4a 4d 50 20 6f 73 6e 65 77 6c 0d 20 | JMP osnewl. |
00002bc0 20 39 35 30 20 2e 64 65 63 69 6d 61 6c 0d 20 20 | 950 .decimal. |
00002bd0 39 36 30 20 20 20 20 20 20 20 20 20 53 45 44 0d |960 SED.|
00002be0 20 20 39 37 30 20 20 20 20 20 20 20 20 20 43 4c | 970 CL|
00002bf0 43 0d 20 20 39 38 30 20 20 20 20 20 20 20 20 20 |C. 980 |
00002c00 41 44 43 20 23 30 0d 20 20 39 39 30 20 20 20 20 |ADC #0. 990 |
00002c10 20 20 20 20 20 43 4c 44 0d 20 31 30 30 30 20 20 | CLD. 1000 |
00002c20 20 20 20 20 20 20 20 50 48 41 0d 20 31 30 31 30 | PHA. 1010|
00002c30 20 20 20 20 20 20 20 20 20 4c 53 52 20 41 0d 20 | LSR A. |
00002c40 31 30 32 30 20 20 20 20 20 20 20 20 20 4c 53 52 |1020 LSR|
00002c50 20 41 0d 20 31 30 33 30 20 20 20 20 20 20 20 20 | A. 1030 |
00002c60 20 4c 53 52 20 41 0d 20 31 30 34 30 20 20 20 20 | LSR A. 1040 |
00002c70 20 20 20 20 20 4c 53 52 20 41 0d 20 31 30 35 30 | LSR A. 1050|
00002c80 20 20 20 20 20 20 20 20 20 4a 53 52 20 6e 69 62 | JSR nib|
00002c90 62 6c 65 2b 64 69 66 66 0d 20 31 30 36 30 20 20 |ble+diff. 1060 |
00002ca0 20 20 20 20 20 20 20 50 4c 41 0d 20 31 30 37 30 | PLA. 1070|
00002cb0 20 20 20 20 20 20 20 20 20 41 4e 44 20 23 26 46 | AND #&F|
00002cc0 0d 20 31 30 38 30 20 2e 6e 69 62 62 6c 65 0d 20 |. 1080 .nibble. |
00002cd0 31 30 39 30 20 20 20 20 20 20 20 20 20 43 4c 43 |1090 CLC|
00002ce0 0d 20 31 31 30 30 20 20 20 20 20 20 20 20 20 41 |. 1100 A|
00002cf0 44 43 20 23 41 53 43 28 22 30 22 29 0d 20 31 31 |DC #ASC("0"). 11|
00002d00 31 30 20 20 20 20 20 20 20 20 20 4a 4d 50 20 6f |10 JMP o|
00002d10 73 61 73 63 69 0d 20 31 31 32 30 20 2e 6c 61 73 |sasci. 1120 .las|
00002d20 74 62 79 74 65 0d 20 31 31 33 30 20 5d 0d 20 31 |tbyte. 1130 ]. 1|
00002d30 31 34 30 20 4e 45 58 54 0d 20 31 31 35 30 20 49 |140 NEXT. 1150 I|
00002d40 4e 50 55 54 27 22 53 61 76 65 20 66 69 6c 65 6e |NPUT'"Save filen|
00002d50 61 6d 65 20 3d 20 22 66 69 6c 65 6e 61 6d 65 24 |ame = "filename$|
00002d60 0d 20 31 31 36 30 20 49 46 20 66 69 6c 65 6e 61 |. 1160 IF filena|
00002d70 6d 65 24 3d 22 22 20 45 4e 44 0d 20 31 31 37 30 |me$="" END. 1170|
00002d80 20 24 73 61 76 65 3d 22 53 41 56 45 20 22 2b 66 | $save="SAVE "+f|
00002d90 69 6c 65 6e 61 6d 65 24 2b 22 20 22 2b 53 54 52 |ilename$+" "+STR|
00002da0 24 7e 28 48 49 4d 45 4d 29 2b 22 20 22 2b 53 54 |$~(HIMEM)+" "+ST|
00002db0 52 24 7e 28 6c 61 73 0d 20 20 20 20 20 20 74 62 |R$~(las. tb|
00002dc0 79 74 65 29 2b 22 20 46 46 46 46 38 30 30 30 20 |yte)+" FFFF8000 |
00002dd0 46 46 46 46 38 30 30 30 22 0d 20 31 31 38 30 20 |FFFF8000". 1180 |
00002de0 58 25 3d 73 61 76 65 20 4d 4f 44 20 32 35 36 0d |X%=save MOD 256.|
00002df0 20 31 31 39 30 20 59 25 3d 73 61 76 65 20 44 49 | 1190 Y%=save DI|
00002e00 56 20 32 35 36 0d 20 31 32 30 30 20 2a 4f 50 54 |V 256. 1200 *OPT|
00002e10 31 2c 32 0d 20 31 32 31 30 20 43 41 4c 4c 20 6f |1,2. 1210 CALL o|
00002e20 73 63 6c 69 0d 20 31 32 32 30 20 2a 4f 50 54 31 |scli. 1220 *OPT1|
00002e30 2c 30 0d 20 31 32 33 30 20 45 4e 44 0d 20 31 32 |,0. 1230 END. 12|
00002e40 34 30 20 44 45 46 46 4e 65 71 75 62 28 62 79 74 |40 DEFFNequb(byt|
00002e50 65 29 0d 20 31 32 35 30 20 3f 50 25 3d 62 79 74 |e). 1250 ?P%=byt|
00002e60 65 0d 20 31 32 36 30 20 50 25 3d 50 25 2b 31 0d |e. 1260 P%=P%+1.|
00002e70 20 31 32 37 30 20 3d 70 61 73 73 0d 20 31 32 38 | 1270 =pass. 128|
00002e80 30 20 44 45 46 46 4e 65 71 75 77 28 77 6f 72 64 |0 DEFFNequw(word|
00002e90 29 0d 20 31 32 39 30 20 3f 50 25 3d 77 6f 72 64 |). 1290 ?P%=word|
00002ea0 20 4d 4f 44 20 32 35 36 0d 20 31 33 30 30 20 50 | MOD 256. 1300 P|
00002eb0 25 3f 31 3d 77 6f 72 64 20 44 49 56 20 32 35 36 |%?1=word DIV 256|
00002ec0 0d 20 31 33 31 30 20 50 25 3d 50 25 2b 32 0d 20 |. 1310 P%=P%+2. |
00002ed0 31 33 32 30 20 3d 70 61 73 73 0d 20 31 33 33 30 |1320 =pass. 1330|
00002ee0 20 44 45 46 46 4e 65 71 75 64 28 64 6f 75 62 6c | DEFFNequd(doubl|
00002ef0 65 29 0d 20 31 33 34 30 20 21 50 25 3d 64 6f 75 |e). 1340 !P%=dou|
00002f00 62 6c 65 0d 20 31 33 35 30 20 50 25 3d 50 25 2b |ble. 1350 P%=P%+|
00002f10 34 0d 20 31 33 36 30 20 3d 70 61 73 73 0d 20 31 |4. 1360 =pass. 1|
00002f20 33 37 30 20 44 45 46 46 4e 65 71 75 73 28 73 74 |370 DEFFNequs(st|
00002f30 72 69 6e 67 24 29 0d 20 31 33 38 30 20 24 50 25 |ring$). 1380 $P%|
00002f40 3d 73 74 72 69 6e 67 24 0d 20 31 33 39 30 20 50 |=string$. 1390 P|
00002f50 25 3d 50 25 2b 4c 45 4e 28 73 74 72 69 6e 67 24 |%=P%+LEN(string$|
00002f60 29 0d 20 31 34 30 30 20 3d 70 61 73 73 0d |). 1400 =pass.|
00002f6e 
27_11_87/T\SWR06.m0
27_11_87/T\SWR06.m1
27_11_87/T\SWR06.m2
27_11_87/T\SWR06.m4
27_11_87/T\SWR06.m5
.