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11_12_87/T\SWR08
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: | 11_12_87/T\SWR08 |
| Read OK: | ✔ |
| File size: | 2FB7 bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
Duplicates
There is 1 duplicate copy of this file in the archive:
- CEEFAX disks » telesoftware3.adl » 11_12_87/T\SWR08
- CEEFAX disks » telesoftware9.adl » 26-08-88/T\SWR08
File contents
Mastering Sideways ROM & RAM - Module 08 - Service rom errors
-------------------------------------------------------------
In Module 4 you were shown how to use the DFS command *ENABLE within
your own SWR programs. If you look carefully at the program ENABLE
used to illustrate Module 4 you will see that the reset routine is
only executed if *ENABLE is typed before *RESET. If any other command
is typed before *RESET the interpreter simply returns control to the
MOS with the accumulator reset to zero. This is the simplest form of
error handling - if the user types something unexpected return with
the accumulator reset to zero.
In this module I will show you how to deal with user generated
errors within SWR service routines in such a way that an error will
abort a BASIC program and print an appropriate error message. The way
of dealing with errors in language roms is different from the method
described here and will be dealt with in Module 17.
Figure 8.1 illustrates how the DFS rom responds to user generated
errors such as neglecting to include a mandatory argument. If you
enter the DFS command *TYPE without an argument, the DFS responds by
making the current language print the syntax it expects. If you make
the same mistake within a running BASIC program the DFS makes the
syntax message available to BASIC and aborts the BASIC program. BASIC
then prints the message and the line number in which the error was
generated.
>*TYPE
Syntax: TYPE <fsp>
>NEW
>10 *TYPE
>20 STOP
>RUN
Syntax: TYPE <fsp> at line 10
>
Figure 8.1 Error handling by the DFS
------------------------------------
The DFS handles the syntax error by copying the appropriate error
message from the DFS rom into the error message buffer at the bottom
of the hardware stack, from &100 upwards, and then jumping to &100.
Figure 8.2 is a hexadecimal and ASCII dump of the error message
buffer following the syntax error generated in figure 8.1.
0100 00 DC 53 79 6E 74 61 78 ..Syntax
0108 3A 20 54 59 50 45 20 3C : TYPE <
0110 66 73 70 3E 00 00 00 00 fsp>....
0118 00 00 00 00 00 00 00 00 ........
Figure 8.2 A memory dump of the error message buffer
-----------------------------------------------------
The first byte of the error message buffer is the BRK opcode &00.
The next byte is the error number, in this example &DC. The error
number is followed by the message "Syntax: TYPE <fsp>" and then
another BRK opcode.
The DFS rom passed control to the error buffer by jumping to &100.
The MOS, after processing the BRK instruction, passed control to the
BASIC error handler which printed the message starting at &102 until
it encountered the next BRK opcode at &114. When the error was
generated by a command within a BASIC program, BASIC added " at line
10" onto the end of the DFS error message.
When the MOS processes a BRK instruction it issues service call 6 to
all the sideways roms. When service call 6 is issued, the address of
the error message number is stored in &FD (low byte) and &FE (high
byte). Location &F0 contains a copy of the stack pointer after the BRK
was executed and Osbyte &BA (or the less respectable method of peeking
location &24A) can be used to find the number of the rom in use when
the error was generated. This information will be used in Module 13
when trapping errors generated in other roms is covered.
User generated errors within your service roms should be dealt with
in the same way that the DFS deals with them. You should copy an error
message, starting and ending with the BRK opcode, into the error
buffer and then jump to &100 so that the MOS and currently active
language can take responsibility for the error handling. An error
number normally follows the first BRK opcode but you would be wise to
use a second BRK in place of an error number unless your routine has
been given an official error number by Acorn. You are unlikely to get
an official error number unless you intend to market your programs.
.
.
.
.mistake
LDX #message MOD 256 \ low byte of error message
LDY #message DIV 256 \ high byte of error message
JMP error \ jump to error handler
.message
BRK \ BRK opcode
BRK \ error number zero
EQUS "User error"
BRK \ last byte
EQUB &FF \ message termination character
.
.
.
.error
STX &70 \ store X and Y
STY &71 \ for indirect addressing
LDY #&FF \ initialise offset
.errorloop
INY \ increment offset
LDA (&70),Y \ read next byte of message
STA &100,Y \ copy into error buffer
BPL errorloop \ branch if not termination character
JMP &100 \ jump to first BRK
.
.
.
Figure 8.3 User generated error handling.
------------------------------------------
In the outline error handling routine in figure 8.3, control will be
passed to the label ".mistake" after detecting a user generated error.
The X and Y registers are loaded with the address of the error message
and control is passed to the label ".error". The error message is
copied from the rom into the error buffer. The copying stops when &FF
is found at the end of the error message and control is then passed to
&100. The MOS and the currently active language can then take over the
error processing. There is no need to balance the stack before jumping
to the BRK instruction at &100.
If you have been following the course, you should by now have enough
experience to modify the program ENABLE (from Module 4) to include
this more sophisticated error handling technique.
The error handler in figure 8.3 has been used in the program ERROR.
This program uses the now familiar one command interpreter to
implement the new command *CHECK (0-6). This syntax means that the
command must have an argument in the range from 0 to 6 inclusive. If
the argument is outside that range or missing there is a syntax error.
The command can be used from within a BASIC program to check which
filing system is active. If it is not the one you want, as specified
by the argument, then the routine responds with an incorrect filing
system error message and aborts the BASIC program. If the active
filing system is the one you want then the program will continue
running without interuption.
The different filing systems are represented by the argument as
follows:
0 No filing system active,
1 1200 baud cassette,
2 300 baud cassette,
3 Rom filing system,
4 Disc filing system,
5 Econet filing system,
6 Telesoftware filing system.
If you use the command *CHECK without an argument in a BASIC
program, the program will abort with an error message "Syntax: *CHECK
(0-6) in line xxx". If the DFS is active and you include the command
*CHECK 1 in a BASIC program, the program will abort with an error
message "Incorrect filing system in line xxx".
When the interpreter (lines 290-570) recognises the new command it
passes control to the label ".found" (line 580). The argument is
initialised (lines 590-600) and the two zero page memory locations
used by the routine are pushed on the stack (lines 610-640). The
argument is read (line 650). If no argument is found (line 660)
control is passed to the label ".mistake" (line 710).
After reading the argument it is converted into binary and checked
to see if it is in range (lines 670-700). If it is not in range
control is passed to the label ".mistake" (line 710). If it is in
range the binary representation of the argument is pushed on the stack
(line 760), the accumulator and index registers are reset to zero
(lines 770-790) and Osargs is called (line 800).
The active filing system is returned in the accumulator and stored
in &70 (line 810). The argument is pulled off the stack and compared
with the active filing system number (lines 820-830). If they are
identical the routine restores the zero page locations (lines
890-920), balances the stack (lines 930-950) and returns control to
the MOS after reseting the accumulator to zero (lines 960-970). If the
active filing system number is not the same as the argument the
routine generates the incorrect filing system error message (lines
850-870).
The error handler (lines 980-1110) is a little different from the
one in figure 8.3 because it restores the two zero page bytes at &70
and &71 before jumping to &100. The registers pushed on the stack by
the interpreter are not pulled off before jumping to &100 because the
stack is reset by the language error handler after executing the BRK
instruction at &100.
10 REM: ERROR
20 MODE7
30 HIMEM=&3C00
40 DIM save 50
50 diff=&8000-HIMEM
60 address=&70
70 comvec=&F2
80 errstack=&100
90 gsinit=&FFC2
100 gsread=&FFC5
110 osargs=&FFDA
120 oscli=&FFF7
130 FOR pass = 0 TO 2 STEP 2
140 P%=HIMEM
150 [ OPT pass
160 BRK
170 BRK
180 BRK
190 JMP service+diff
200 OPT FNequb(&82)
210 OPT FNequb((copyright+diff) MOD 256)
220 BRK
230 .title
240 OPT FNequs("CHECK")
250 .copyright
260 BRK
270 OPT FNequs("(C) Gordon Horsington 1987")
280 BRK
290 .service
300 CMP #4
310 BEQ unrecognised
320 .exit
330 RTS
340 .unrecognised
350 PHA
360 TXA
370 PHA
380 TYA
390 PHA
400 LDX #&FF
410 .comloop
420 INX
430 LDA title+diff,X
440 BEQ found
450 LDA (comvec),Y
460 INY
470 CMP #ASC(".")
480 BEQ found
490 AND #&DF
500 CMP title+diff,X
510 BEQ comloop
520 PLA
530 TAY
540 PLA
550 TAX
560 PLA
570 RTS
580 .found
590 SEC
600 JSR gsinit
610 LDA address
620 PHA
630 LDA address+1
640 PHA
650 JSR gsread
660 BCS mistake
670 SEC
680 SBC #ASC("0")
690 CMP #7
700 BCC file
710 .mistake
720 LDX #(syntax+diff) MOD 256
730 LDY #(syntax+diff) DIV 256
740 JMP error+diff
750 .file
760 PHA
770 LDA #0
780 TAX
790 TAY
800 JSR osargs
810 STA address
820 PLA
830 CMP address
840 BEQ correct
850 LDX #(wrong+diff) MOD 256
860 LDY #(wrong+diff) DIV 256
870 JMP error+diff
880 .correct
890 PLA
900 STA address+1
910 PLA
920 STA address
930 PLA
940 PLA
950 PLA
960 LDA #0
970 RTS
980 .error
990 STX address
1000 STY address+1
1010 LDY #&FF
1020 .errorloop
1030 INY
1040 LDA (address),Y
1050 STA errstack,Y
1060 BPL errorloop
1070 PLA
1080 STA address+1
1090 PLA
1100 STA address
1110 JMP errstack
1120 .syntax
1130 BRK
1140 BRK
1150 OPT FNequs("Syntax")
1160 OPT FNequb(&3A)
1170 OPT FNequs(" *CHECK (0-6)")
1180 BRK
1190 OPT FNequb(&FF)
1200 .wrong
1210 BRK
1220 BRK
1230 OPT FNequs("Incorrect filing system")
1240 BRK
1250 OPT FNequb(&FF)
1260 .lastbyte
1270 ]
1280 NEXT
1290 INPUT'"Save filename = "filename$
1300 IF filename$="" END
1310 $save="SAVE "+filename$+" "+STR$~(HIMEM)+" "+STR$~(las
tbyte)+" FFFF8000 FFFF8000"
1320 X%=save MOD 256
1330 Y%=save DIV 256
1340 *OPT1,2
1350 CALL oscli
1360 *OPT1,0
1370 END
1380 DEFFNequb(byte)
1390 ?P%=byte
1400 P%=P%+1
1410 =pass
1420 DEFFNequw(word)
1430 ?P%=word MOD 256
1440 P%?1=word DIV 256
1450 P%=P%+2
1460 =pass
1470 DEFFNequd(double)
1480 !P%=double
1490 P%=P%+4
1500 =pass
1510 DEFFNequs(string$)
1520 $P%=string$
1530 P%=P%+LEN(string$)
1540 =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 38 20 2d 20 53 65 72 76 69 |odule 08 - Servi|
00000030 63 65 20 72 6f 6d 20 65 72 72 6f 72 73 0d 2d 2d |ce rom errors.--|
00000040 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------|
*
00000070 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 0d 0d 20 20 49 |-----------.. I|
00000080 6e 20 4d 6f 64 75 6c 65 20 34 20 79 6f 75 20 77 |n Module 4 you w|
00000090 65 72 65 20 73 68 6f 77 6e 20 68 6f 77 20 74 6f |ere shown how to|
000000a0 20 75 73 65 20 74 68 65 20 44 46 53 20 63 6f 6d | use the DFS com|
000000b0 6d 61 6e 64 20 2a 45 4e 41 42 4c 45 20 77 69 74 |mand *ENABLE wit|
000000c0 68 69 6e 0d 79 6f 75 72 20 6f 77 6e 20 53 57 52 |hin.your own SWR|
000000d0 20 70 72 6f 67 72 61 6d 73 2e 20 49 66 20 79 6f | programs. If yo|
000000e0 75 20 6c 6f 6f 6b 20 63 61 72 65 66 75 6c 6c 79 |u look carefully|
000000f0 20 61 74 20 74 68 65 20 70 72 6f 67 72 61 6d 20 | at the program |
00000100 45 4e 41 42 4c 45 0d 75 73 65 64 20 74 6f 20 69 |ENABLE.used to i|
00000110 6c 6c 75 73 74 72 61 74 65 20 4d 6f 64 75 6c 65 |llustrate Module|
00000120 20 34 20 79 6f 75 20 77 69 6c 6c 20 73 65 65 20 | 4 you will see |
00000130 74 68 61 74 20 74 68 65 20 72 65 73 65 74 20 72 |that the reset r|
00000140 6f 75 74 69 6e 65 20 69 73 0d 6f 6e 6c 79 20 65 |outine is.only e|
00000150 78 65 63 75 74 65 64 20 69 66 20 2a 45 4e 41 42 |xecuted if *ENAB|
00000160 4c 45 20 69 73 20 74 79 70 65 64 20 62 65 66 6f |LE is typed befo|
00000170 72 65 20 2a 52 45 53 45 54 2e 20 49 66 20 61 6e |re *RESET. If an|
00000180 79 20 6f 74 68 65 72 20 63 6f 6d 6d 61 6e 64 0d |y other command.|
00000190 69 73 20 74 79 70 65 64 20 62 65 66 6f 72 65 20 |is typed before |
000001a0 2a 52 45 53 45 54 20 74 68 65 20 69 6e 74 65 72 |*RESET the inter|
000001b0 70 72 65 74 65 72 20 73 69 6d 70 6c 79 20 72 65 |preter simply re|
000001c0 74 75 72 6e 73 20 63 6f 6e 74 72 6f 6c 20 74 6f |turns control to|
000001d0 20 74 68 65 0d 4d 4f 53 20 77 69 74 68 20 74 68 | the.MOS with th|
000001e0 65 20 61 63 63 75 6d 75 6c 61 74 6f 72 20 72 65 |e accumulator re|
000001f0 73 65 74 20 74 6f 20 7a 65 72 6f 2e 20 54 68 69 |set to zero. Thi|
00000200 73 20 69 73 20 74 68 65 20 73 69 6d 70 6c 65 73 |s is the simples|
00000210 74 20 66 6f 72 6d 20 6f 66 0d 65 72 72 6f 72 20 |t form of.error |
00000220 68 61 6e 64 6c 69 6e 67 20 2d 20 69 66 20 74 68 |handling - if th|
00000230 65 20 75 73 65 72 20 74 79 70 65 73 20 73 6f 6d |e user types som|
00000240 65 74 68 69 6e 67 20 75 6e 65 78 70 65 63 74 65 |ething unexpecte|
00000250 64 20 72 65 74 75 72 6e 20 77 69 74 68 0d 74 68 |d return with.th|
00000260 65 20 61 63 63 75 6d 75 6c 61 74 6f 72 20 72 65 |e accumulator re|
00000270 73 65 74 20 74 6f 20 7a 65 72 6f 2e 0d 0d 20 20 |set to zero... |
00000280 49 6e 20 74 68 69 73 20 6d 6f 64 75 6c 65 20 49 |In this module I|
00000290 20 77 69 6c 6c 20 73 68 6f 77 20 79 6f 75 20 68 | will show you h|
000002a0 6f 77 20 74 6f 20 64 65 61 6c 20 77 69 74 68 20 |ow to deal with |
000002b0 75 73 65 72 20 67 65 6e 65 72 61 74 65 64 0d 65 |user generated.e|
000002c0 72 72 6f 72 73 20 77 69 74 68 69 6e 20 53 57 52 |rrors within SWR|
000002d0 20 73 65 72 76 69 63 65 20 72 6f 75 74 69 6e 65 | service routine|
000002e0 73 20 69 6e 20 73 75 63 68 20 61 20 77 61 79 20 |s in such a way |
000002f0 74 68 61 74 20 61 6e 20 65 72 72 6f 72 20 77 69 |that an error wi|
00000300 6c 6c 0d 61 62 6f 72 74 20 61 20 42 41 53 49 43 |ll.abort a BASIC|
00000310 20 70 72 6f 67 72 61 6d 20 61 6e 64 20 70 72 69 | program and pri|
00000320 6e 74 20 61 6e 20 61 70 70 72 6f 70 72 69 61 74 |nt an appropriat|
00000330 65 20 65 72 72 6f 72 20 6d 65 73 73 61 67 65 2e |e error message.|
00000340 20 54 68 65 20 77 61 79 0d 6f 66 20 64 65 61 6c | The way.of deal|
00000350 69 6e 67 20 77 69 74 68 20 65 72 72 6f 72 73 20 |ing with errors |
00000360 69 6e 20 6c 61 6e 67 75 61 67 65 20 72 6f 6d 73 |in language roms|
00000370 20 69 73 20 64 69 66 66 65 72 65 6e 74 20 66 72 | is different fr|
00000380 6f 6d 20 74 68 65 20 6d 65 74 68 6f 64 0d 64 65 |om the method.de|
00000390 73 63 72 69 62 65 64 20 68 65 72 65 20 61 6e 64 |scribed here and|
000003a0 20 77 69 6c 6c 20 62 65 20 64 65 61 6c 74 20 77 | will be dealt w|
000003b0 69 74 68 20 69 6e 20 4d 6f 64 75 6c 65 20 31 37 |ith in Module 17|
000003c0 2e 0d 0d 20 20 46 69 67 75 72 65 20 38 2e 31 20 |... Figure 8.1 |
000003d0 69 6c 6c 75 73 74 72 61 74 65 73 20 68 6f 77 20 |illustrates how |
000003e0 74 68 65 20 44 46 53 20 72 6f 6d 20 72 65 73 70 |the DFS rom resp|
000003f0 6f 6e 64 73 20 74 6f 20 75 73 65 72 20 67 65 6e |onds to user gen|
00000400 65 72 61 74 65 64 0d 65 72 72 6f 72 73 20 73 75 |erated.errors su|
00000410 63 68 20 61 73 20 6e 65 67 6c 65 63 74 69 6e 67 |ch as neglecting|
00000420 20 74 6f 20 69 6e 63 6c 75 64 65 20 61 20 6d 61 | to include a ma|
00000430 6e 64 61 74 6f 72 79 20 61 72 67 75 6d 65 6e 74 |ndatory argument|
00000440 2e 20 49 66 20 79 6f 75 0d 65 6e 74 65 72 20 74 |. If you.enter t|
00000450 68 65 20 44 46 53 20 63 6f 6d 6d 61 6e 64 20 2a |he DFS command *|
00000460 54 59 50 45 20 77 69 74 68 6f 75 74 20 61 6e 20 |TYPE without an |
00000470 61 72 67 75 6d 65 6e 74 2c 20 74 68 65 20 44 46 |argument, the DF|
00000480 53 20 72 65 73 70 6f 6e 64 73 20 62 79 0d 6d 61 |S responds by.ma|
00000490 6b 69 6e 67 20 74 68 65 20 63 75 72 72 65 6e 74 |king the current|
000004a0 20 6c 61 6e 67 75 61 67 65 20 70 72 69 6e 74 20 | language print |
000004b0 74 68 65 20 73 79 6e 74 61 78 20 69 74 20 65 78 |the syntax it ex|
000004c0 70 65 63 74 73 2e 20 49 66 20 79 6f 75 20 6d 61 |pects. If you ma|
000004d0 6b 65 0d 74 68 65 20 73 61 6d 65 20 6d 69 73 74 |ke.the same mist|
000004e0 61 6b 65 20 77 69 74 68 69 6e 20 61 20 72 75 6e |ake within a run|
000004f0 6e 69 6e 67 20 42 41 53 49 43 20 70 72 6f 67 72 |ning BASIC progr|
00000500 61 6d 20 74 68 65 20 44 46 53 20 6d 61 6b 65 73 |am the DFS makes|
00000510 20 74 68 65 0d 73 79 6e 74 61 78 20 6d 65 73 73 | the.syntax mess|
00000520 61 67 65 20 61 76 61 69 6c 61 62 6c 65 20 74 6f |age available to|
00000530 20 42 41 53 49 43 20 61 6e 64 20 61 62 6f 72 74 | BASIC and abort|
00000540 73 20 74 68 65 20 42 41 53 49 43 20 70 72 6f 67 |s the BASIC prog|
00000550 72 61 6d 2e 20 42 41 53 49 43 0d 74 68 65 6e 20 |ram. BASIC.then |
00000560 70 72 69 6e 74 73 20 74 68 65 20 6d 65 73 73 61 |prints the messa|
00000570 67 65 20 61 6e 64 20 74 68 65 20 6c 69 6e 65 20 |ge and the line |
00000580 6e 75 6d 62 65 72 20 69 6e 20 77 68 69 63 68 20 |number in which |
00000590 74 68 65 20 65 72 72 6f 72 20 77 61 73 0d 67 65 |the error was.ge|
000005a0 6e 65 72 61 74 65 64 2e 0d 0d 0d 0d 3e 2a 54 59 |nerated.....>*TY|
000005b0 50 45 0d 0d 53 79 6e 74 61 78 3a 20 54 59 50 45 |PE..Syntax: TYPE|
000005c0 20 3c 66 73 70 3e 0d 3e 4e 45 57 0d 3e 31 30 20 | <fsp>.>NEW.>10 |
000005d0 2a 54 59 50 45 0d 3e 32 30 20 53 54 4f 50 0d 3e |*TYPE.>20 STOP.>|
000005e0 52 55 4e 0d 0d 53 79 6e 74 61 78 3a 20 54 59 50 |RUN..Syntax: TYP|
000005f0 45 20 3c 66 73 70 3e 20 61 74 20 6c 69 6e 65 20 |E <fsp> at line |
00000600 31 30 0d 3e 0d 0d 46 69 67 75 72 65 20 38 2e 31 |10.>..Figure 8.1|
00000610 20 45 72 72 6f 72 20 68 61 6e 64 6c 69 6e 67 20 | Error handling |
00000620 62 79 20 74 68 65 20 44 46 53 0d 2d 2d 2d 2d 2d |by the DFS.-----|
00000630 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------|
00000640 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 0d |---------------.|
00000650 0d 0d 0d 20 20 54 68 65 20 44 46 53 20 68 61 6e |... The DFS han|
00000660 64 6c 65 73 20 74 68 65 20 73 79 6e 74 61 78 20 |dles the syntax |
00000670 65 72 72 6f 72 20 62 79 20 63 6f 70 79 69 6e 67 |error by copying|
00000680 20 74 68 65 20 61 70 70 72 6f 70 72 69 61 74 65 | the appropriate|
00000690 20 65 72 72 6f 72 0d 6d 65 73 73 61 67 65 20 66 | error.message f|
000006a0 72 6f 6d 20 74 68 65 20 44 46 53 20 72 6f 6d 20 |rom the DFS rom |
000006b0 69 6e 74 6f 20 74 68 65 20 65 72 72 6f 72 20 6d |into the error m|
000006c0 65 73 73 61 67 65 20 62 75 66 66 65 72 20 61 74 |essage buffer at|
000006d0 20 74 68 65 20 62 6f 74 74 6f 6d 0d 6f 66 20 74 | the bottom.of t|
000006e0 68 65 20 68 61 72 64 77 61 72 65 20 73 74 61 63 |he hardware stac|
000006f0 6b 2c 20 66 72 6f 6d 20 26 31 30 30 20 75 70 77 |k, from &100 upw|
00000700 61 72 64 73 2c 20 61 6e 64 20 74 68 65 6e 20 6a |ards, and then j|
00000710 75 6d 70 69 6e 67 20 74 6f 20 26 31 30 30 2e 0d |umping to &100..|
00000720 0d 20 20 46 69 67 75 72 65 20 38 2e 32 20 69 73 |. Figure 8.2 is|
00000730 20 61 20 68 65 78 61 64 65 63 69 6d 61 6c 20 61 | a hexadecimal a|
00000740 6e 64 20 41 53 43 49 49 20 64 75 6d 70 20 6f 66 |nd ASCII dump of|
00000750 20 74 68 65 20 65 72 72 6f 72 20 6d 65 73 73 61 | the error messa|
00000760 67 65 0d 62 75 66 66 65 72 20 66 6f 6c 6c 6f 77 |ge.buffer follow|
00000770 69 6e 67 20 74 68 65 20 73 79 6e 74 61 78 20 65 |ing the syntax e|
00000780 72 72 6f 72 20 67 65 6e 65 72 61 74 65 64 20 69 |rror generated i|
00000790 6e 20 66 69 67 75 72 65 20 38 2e 31 2e 0d 0d 0d |n figure 8.1....|
000007a0 0d 0d 0d 30 31 30 30 20 20 30 30 20 44 43 20 35 |...0100 00 DC 5|
000007b0 33 20 37 39 20 36 45 20 37 34 20 36 31 20 37 38 |3 79 6E 74 61 78|
000007c0 20 20 2e 2e 53 79 6e 74 61 78 0d 30 31 30 38 20 | ..Syntax.0108 |
000007d0 20 33 41 20 32 30 20 35 34 20 35 39 20 35 30 20 | 3A 20 54 59 50 |
000007e0 34 35 20 32 30 20 33 43 20 20 3a 20 54 59 50 45 |45 20 3C : TYPE|
000007f0 20 3c 0d 30 31 31 30 20 20 36 36 20 37 33 20 37 | <.0110 66 73 7|
00000800 30 20 33 45 20 30 30 20 30 30 20 30 30 20 30 30 |0 3E 00 00 00 00|
00000810 20 20 66 73 70 3e 2e 2e 2e 2e 0d 30 31 31 38 20 | fsp>.....0118 |
00000820 20 30 30 20 30 30 20 30 30 20 30 30 20 30 30 20 | 00 00 00 00 00 |
00000830 30 30 20 30 30 20 30 30 20 20 2e 2e 2e 2e 2e 2e |00 00 00 ......|
00000840 2e 2e 0d 0d 46 69 67 75 72 65 20 38 2e 32 20 20 |....Figure 8.2 |
00000850 41 20 6d 65 6d 6f 72 79 20 64 75 6d 70 20 6f 66 |A memory dump of|
00000860 20 74 68 65 20 65 72 72 6f 72 20 6d 65 73 73 61 | the error messa|
00000870 67 65 20 62 75 66 66 65 72 0d 2d 2d 2d 2d 2d 2d |ge buffer.------|
00000880 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d |----------------|
*
000008a0 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 2d 0d |---------------.|
000008b0 0d 0d 0d 0d 20 20 54 68 65 20 66 69 72 73 74 20 |.... The first |
000008c0 62 79 74 65 20 6f 66 20 74 68 65 20 65 72 72 6f |byte of the erro|
000008d0 72 20 6d 65 73 73 61 67 65 20 62 75 66 66 65 72 |r message buffer|
000008e0 20 69 73 20 74 68 65 20 42 52 4b 20 6f 70 63 6f | is the BRK opco|
000008f0 64 65 20 26 30 30 2e 0d 54 68 65 20 6e 65 78 74 |de &00..The next|
00000900 20 62 79 74 65 20 69 73 20 74 68 65 20 65 72 72 | byte is the err|
00000910 6f 72 20 6e 75 6d 62 65 72 2c 20 69 6e 20 74 68 |or number, in th|
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00002a70 20 20 20 20 20 20 20 50 4c 41 0d 20 20 39 35 30 | PLA. 950|
00002a80 20 20 20 20 20 20 20 20 20 50 4c 41 0d 20 20 39 | PLA. 9|
00002a90 36 30 20 20 20 20 20 20 20 20 20 4c 44 41 20 23 |60 LDA #|
00002aa0 30 0d 20 20 39 37 30 20 20 20 20 20 20 20 20 20 |0. 970 |
00002ab0 52 54 53 0d 20 20 39 38 30 20 2e 65 72 72 6f 72 |RTS. 980 .error|
00002ac0 0d 20 20 39 39 30 20 20 20 20 20 20 20 20 20 53 |. 990 S|
00002ad0 54 58 20 61 64 64 72 65 73 73 0d 20 31 30 30 30 |TX address. 1000|
00002ae0 20 20 20 20 20 20 20 20 20 53 54 59 20 61 64 64 | STY add|
00002af0 72 65 73 73 2b 31 0d 20 31 30 31 30 20 20 20 20 |ress+1. 1010 |
00002b00 20 20 20 20 20 4c 44 59 20 23 26 46 46 0d 20 31 | LDY #&FF. 1|
00002b10 30 32 30 20 2e 65 72 72 6f 72 6c 6f 6f 70 0d 20 |020 .errorloop. |
00002b20 31 30 33 30 20 20 20 20 20 20 20 20 20 49 4e 59 |1030 INY|
00002b30 0d 20 31 30 34 30 20 20 20 20 20 20 20 20 20 4c |. 1040 L|
00002b40 44 41 20 28 61 64 64 72 65 73 73 29 2c 59 0d 20 |DA (address),Y. |
00002b50 31 30 35 30 20 20 20 20 20 20 20 20 20 53 54 41 |1050 STA|
00002b60 20 65 72 72 73 74 61 63 6b 2c 59 0d 20 31 30 36 | errstack,Y. 106|
00002b70 30 20 20 20 20 20 20 20 20 20 42 50 4c 20 65 72 |0 BPL er|
00002b80 72 6f 72 6c 6f 6f 70 0d 20 31 30 37 30 20 20 20 |rorloop. 1070 |
00002b90 20 20 20 20 20 20 50 4c 41 0d 20 31 30 38 30 20 | PLA. 1080 |
00002ba0 20 20 20 20 20 20 20 20 53 54 41 20 61 64 64 72 | STA addr|
00002bb0 65 73 73 2b 31 0d 20 31 30 39 30 20 20 20 20 20 |ess+1. 1090 |
00002bc0 20 20 20 20 50 4c 41 0d 20 31 31 30 30 20 20 20 | PLA. 1100 |
00002bd0 20 20 20 20 20 20 53 54 41 20 61 64 64 72 65 73 | STA addres|
00002be0 73 0d 20 31 31 31 30 20 20 20 20 20 20 20 20 20 |s. 1110 |
00002bf0 4a 4d 50 20 65 72 72 73 74 61 63 6b 0d 20 31 31 |JMP errstack. 11|
00002c00 32 30 20 2e 73 79 6e 74 61 78 0d 20 31 31 33 30 |20 .syntax. 1130|
00002c10 20 20 20 20 20 20 20 20 20 42 52 4b 0d 20 31 31 | BRK. 11|
00002c20 34 30 20 20 20 20 20 20 20 20 20 42 52 4b 0d 20 |40 BRK. |
00002c30 31 31 35 30 20 20 20 20 20 20 20 20 20 4f 50 54 |1150 OPT|
00002c40 20 46 4e 65 71 75 73 28 22 53 79 6e 74 61 78 22 | FNequs("Syntax"|
00002c50 29 0d 20 31 31 36 30 20 20 20 20 20 20 20 20 20 |). 1160 |
00002c60 4f 50 54 20 46 4e 65 71 75 62 28 26 33 41 29 0d |OPT FNequb(&3A).|
00002c70 20 31 31 37 30 20 20 20 20 20 20 20 20 20 4f 50 | 1170 OP|
00002c80 54 20 46 4e 65 71 75 73 28 22 20 2a 43 48 45 43 |T FNequs(" *CHEC|
00002c90 4b 20 28 30 2d 36 29 22 29 0d 20 31 31 38 30 20 |K (0-6)"). 1180 |
00002ca0 20 20 20 20 20 20 20 20 42 52 4b 0d 20 31 31 39 | BRK. 119|
00002cb0 30 20 20 20 20 20 20 20 20 20 4f 50 54 20 46 4e |0 OPT FN|
00002cc0 65 71 75 62 28 26 46 46 29 0d 20 31 32 30 30 20 |equb(&FF). 1200 |
00002cd0 2e 77 72 6f 6e 67 0d 20 31 32 31 30 20 20 20 20 |.wrong. 1210 |
00002ce0 20 20 20 20 20 42 52 4b 0d 20 31 32 32 30 20 20 | BRK. 1220 |
00002cf0 20 20 20 20 20 20 20 42 52 4b 0d 20 31 32 33 30 | BRK. 1230|
00002d00 20 20 20 20 20 20 20 20 20 4f 50 54 20 46 4e 65 | OPT FNe|
00002d10 71 75 73 28 22 49 6e 63 6f 72 72 65 63 74 20 66 |qus("Incorrect f|
00002d20 69 6c 69 6e 67 20 73 79 73 74 65 6d 22 29 0d 20 |iling system"). |
00002d30 31 32 34 30 20 20 20 20 20 20 20 20 20 42 52 4b |1240 BRK|
00002d40 0d 20 31 32 35 30 20 20 20 20 20 20 20 20 20 4f |. 1250 O|
00002d50 50 54 20 46 4e 65 71 75 62 28 26 46 46 29 0d 20 |PT FNequb(&FF). |
00002d60 31 32 36 30 20 2e 6c 61 73 74 62 79 74 65 0d 20 |1260 .lastbyte. |
00002d70 31 32 37 30 20 5d 0d 20 31 32 38 30 20 4e 45 58 |1270 ]. 1280 NEX|
00002d80 54 0d 20 31 32 39 30 20 49 4e 50 55 54 27 22 53 |T. 1290 INPUT'"S|
00002d90 61 76 65 20 66 69 6c 65 6e 61 6d 65 20 3d 20 22 |ave filename = "|
00002da0 66 69 6c 65 6e 61 6d 65 24 0d 20 31 33 30 30 20 |filename$. 1300 |
00002db0 49 46 20 66 69 6c 65 6e 61 6d 65 24 3d 22 22 20 |IF filename$="" |
00002dc0 45 4e 44 0d 20 31 33 31 30 20 24 73 61 76 65 3d |END. 1310 $save=|
00002dd0 22 53 41 56 45 20 22 2b 66 69 6c 65 6e 61 6d 65 |"SAVE "+filename|
00002de0 24 2b 22 20 22 2b 53 54 52 24 7e 28 48 49 4d 45 |$+" "+STR$~(HIME|
00002df0 4d 29 2b 22 20 22 2b 53 54 52 24 7e 28 6c 61 73 |M)+" "+STR$~(las|
00002e00 0d 20 20 20 20 20 20 74 62 79 74 65 29 2b 22 20 |. tbyte)+" |
00002e10 46 46 46 46 38 30 30 30 20 46 46 46 46 38 30 30 |FFFF8000 FFFF800|
00002e20 30 22 0d 20 31 33 32 30 20 58 25 3d 73 61 76 65 |0". 1320 X%=save|
00002e30 20 4d 4f 44 20 32 35 36 0d 20 31 33 33 30 20 59 | MOD 256. 1330 Y|
00002e40 25 3d 73 61 76 65 20 44 49 56 20 32 35 36 0d 20 |%=save DIV 256. |
00002e50 31 33 34 30 20 2a 4f 50 54 31 2c 32 0d 20 31 33 |1340 *OPT1,2. 13|
00002e60 35 30 20 43 41 4c 4c 20 6f 73 63 6c 69 0d 20 31 |50 CALL oscli. 1|
00002e70 33 36 30 20 2a 4f 50 54 31 2c 30 0d 20 31 33 37 |360 *OPT1,0. 137|
00002e80 30 20 45 4e 44 0d 20 31 33 38 30 20 44 45 46 46 |0 END. 1380 DEFF|
00002e90 4e 65 71 75 62 28 62 79 74 65 29 0d 20 31 33 39 |Nequb(byte). 139|
00002ea0 30 20 3f 50 25 3d 62 79 74 65 0d 20 31 34 30 30 |0 ?P%=byte. 1400|
00002eb0 20 50 25 3d 50 25 2b 31 0d 20 31 34 31 30 20 3d | P%=P%+1. 1410 =|
00002ec0 70 61 73 73 0d 20 31 34 32 30 20 44 45 46 46 4e |pass. 1420 DEFFN|
00002ed0 65 71 75 77 28 77 6f 72 64 29 0d 20 31 34 33 30 |equw(word). 1430|
00002ee0 20 3f 50 25 3d 77 6f 72 64 20 4d 4f 44 20 32 35 | ?P%=word MOD 25|
00002ef0 36 0d 20 31 34 34 30 20 50 25 3f 31 3d 77 6f 72 |6. 1440 P%?1=wor|
00002f00 64 20 44 49 56 20 32 35 36 0d 20 31 34 35 30 20 |d DIV 256. 1450 |
00002f10 50 25 3d 50 25 2b 32 0d 20 31 34 36 30 20 3d 70 |P%=P%+2. 1460 =p|
00002f20 61 73 73 0d 20 31 34 37 30 20 44 45 46 46 4e 65 |ass. 1470 DEFFNe|
00002f30 71 75 64 28 64 6f 75 62 6c 65 29 0d 20 31 34 38 |qud(double). 148|
00002f40 30 20 21 50 25 3d 64 6f 75 62 6c 65 0d 20 31 34 |0 !P%=double. 14|
00002f50 39 30 20 50 25 3d 50 25 2b 34 0d 20 31 35 30 30 |90 P%=P%+4. 1500|
00002f60 20 3d 70 61 73 73 0d 20 31 35 31 30 20 44 45 46 | =pass. 1510 DEF|
00002f70 46 4e 65 71 75 73 28 73 74 72 69 6e 67 24 29 0d |FNequs(string$).|
00002f80 20 31 35 32 30 20 24 50 25 3d 73 74 72 69 6e 67 | 1520 $P%=string|
00002f90 24 0d 20 31 35 33 30 20 50 25 3d 50 25 2b 4c 45 |$. 1530 P%=P%+LE|
00002fa0 4e 28 73 74 72 69 6e 67 24 29 0d 20 31 35 34 30 |N(string$). 1540|
00002fb0 20 3d 70 61 73 73 0d | =pass.|
00002fb7 
11_12_87/T\SWR08.m0
11_12_87/T\SWR08.m1
11_12_87/T\SWR08.m2
11_12_87/T\SWR08.m4
11_12_87/T\SWR08.m5
.