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Charles Anthony
Charles Anthony

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2024-01-23 Debugging ZIP

#zip #todayilearned #z80

The division problem above was caused by an error in TIL; in D/MOD the line

mov1:     ld      d,a     ; store divisor
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Should be

mov1:     ld      e,a     ; store divisor
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This sets up the arguments to $UD/ correctly, resulting in a correct division.

Now ZIP can print numbers:

    DP .
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yields

   FA  OK
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  DP @ .
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yields

   C4F OK
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Started in on the number interpreter….

Debugging revealed a couple of transcription errors, and a assembly dialect issue:

Where TIL codes “ADC  A”, z80asm needs “ADC   A,A”, otherwise it assembles an “ADC  A,IXL” instruction.

Now zip can

   1000 .
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yielding

   1000 OK
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ZIP is printing a garbage character at the end of the “.” string. TIL pushes a space character with the high bit set as an end-of-string marker. I suspect that on Loeliger’s system the terminal ignored the high bit and printed an ordinary space. I am adding a bit of code to clear the high bit.

Works:

   !    C!    @   C@  
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1 2 + 0 OK
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Plus not working.

plus:   dw      $+2              pop     hl      ; get first word         pop     de      ; get second word         add     hl,de   ; add them         push    hl      ; push sum         nxt   
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That sure looks ok

Heh.  I traced “1 2 + .” and it never executed that code.  I made a typo; the “=” keyword has an incorrect entry “+”.

Ok, + works.

1 2 + .                3  OK
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2000 @ .              0  OK 1234 2000 ! 2000 @ .                1234  OK 56 2000 C!  2000 @ .                1256  OK 2000 C@ .                            56  OK 2000 @ . 10 2000 +! 2000 @ .           1256 1266  OK
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+! works

DP @ .                            C52  OK 1234 ,  DP @ .                
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Crash….  comma not working.

Transcription error; forgot the nxt.

DP @ .                C54  OK 1234 , DP @ .          C56  OK C54 @ .               1234  OK
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comma works

2 1 - .              -1  OK
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That’s wrong…

Typo in -1

   db 1, “-1 “
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should be

   db 2,”-1”
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2 1 - .           1  OK 1 2 - .            -1  OK -1 .  -1  OK
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minus works

1 0= .               0  OK 0 0= .                1  OK -1 0= .             0  OK 8000 0= .            0  OK
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0=  works.

1 2+ . 3  OK
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2+ works

1 ABS .          1  OK -1 ABS .         1  OK 0 ASCII .         30  OK F ASCII .          46  OK ASPACE .          20  OK BASE @ . 10  OK 12 C,       crash
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Forgot nxt

DP @ .          C56  OK DP @ C@ .        2  OK 12 C, C56 C@ .    12  OK
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C, works

1234 2000 !  2000 C0SET 2000 @ .             1200  OK
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C0SET works

Skipping CA!

3 CCONSTANT 3  ` RESTART
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Not good.

CREATE FOO       RESTART
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The problem seems to be in CREATE.

Forgot the trailing semi

CREATE FOO  OK 3 CCONSTANT FOO  OK FOO .  FOO ? DP @ .                 C58  OK 3 CCONSTANT FOO               OK C58 C@ .                      3  OK C59 C@ .                      46  OK C5A C@ .                      4F  OK C5B C@ .                      4F  OK FOO  FOO ?
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It is building the dictionary entry correctly, but not finding it.  Almost certainly a problem in the vocabulary words.

CURRENT @ .   A11  OK
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0a11 3c                         inc     a       ; else bump high
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That’s not right.

CURRENT . 0  OK
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Ahh. Not initialized?

Ahh. SYS needs to be page aligned.

CURRENT .           10E  OK CURRENT @ .         9AF  OK 3 CCONSTANT FOO     OK FOO .               3  OK
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Skipping COMPILER, CORE, CONTEXT, CURRENT, DOES>

(Can’t test DOES> without <BUILDS)

1 2 DROP .    1  OK 3 DUP . .        3 3  OK ENTRY .     ENTRY ?
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Typo; length byte wrong.

ENTRY .      C46  OK HERE .      C58  OK LBP .         LBP ?
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Length byte wrong

LBP .       104  OK 1 2 OVER . . .       1 2 1  OK
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Skipping R>

 

1 2 SWAP . .         1 2  OK
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Skipping VOCABULAARY

That’s all of the defined words.

Added tick; crashes.

aspace token dp    OK context @ @ search     OK . 0  OK . 
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Hangs when the address is printed??

Back jump address in *END

' dp .             A9E  OK
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Committed and pushed.

Added *

But:

zip.l.asm:841: error: `,' expected. Remainder of line: _uds ; multiply 16x8          call    _isign  ; field input signs         call    p_uds   ; multiply 16x8         call    _posign ; Justify result
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I have no idea what it is complaining about

Huh. no embedded underscores…  Ok when defined, fail when referenced… only when referenced by call; jumping to them is okay.

2 2 * . 4  OK
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Added

*+LOOP */ */MOD *C+LOOP *CDO *CLEAVE *CLOOP *DO *LEAVE *LOOP
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