[Coco] Color Forth Help Request
Arthur Flexser
flexser at fiu.edu
Sat Feb 21 13:39:02 EST 2015
I'd suggest acquiring a programming tool that allows you to set breakpoints
and single step, which would have quickly turned up the location of the
error. Perhaps VCC allows this as an option?
Art
On Sat, Feb 21, 2015 at 12:20 PM, Stephen Pereira <spereira1952 at comcast.net>
wrote:
> Art & Darren:
>
> Thank you both so very much for your attention and assistance with my
> problem!
>
> As I said in a previous note, I am a good 8080 assembly language
> programmer, but I’m a rank beginner with the 6809. I am not surprised that
> I made this error, but I am surprised that the assembler did not catch it.
>
> I am using the EDTASM6309 that I purchased from Robert Gault. I’ll bet
> he’ll be interested to hear about this.
>
> This would have taken me quite a bit of time to figure out on my own, to
> say the least. I probably would have gone ahead and plugged in a 6809 back
> into my computer in order to be using one machine for all my projects,
> rather than splitting between two different machines.
>
> Thanka a million, guys! I greatly appreciate your help with this!
>
> smp
> --
> Stephen M. Pereira
> Bedford, NH 03110
> KB1SXE
>
>
> > On Feb 20, 2015, at 8:16 PM, Darren A <mechacoco at gmail.com> wrote:
> >
> > On Fri, Feb 20, 2015 at 4:20 PM, Stephen Pereira <
> spereira1952 at comcast.net>
> > wrote:
> >
> >> Here is my code:
> >>
> >> *
> >> * BRUTE FORCE ROUTINE TO LOAD SCREENS 1 THRU 8
> >> * USING THE DECB LOADM ROUTINE
> >> * JAN 2015, SMP
> >> * ERROR CHECK & ADVICE FROM BRETT GORDON
> >> *
> >> FCB $84,'L,'S,'C,'R+$80
> >> FDB SSCR-7
> >> LSCR FDB *+2
> >> PSHS CC,A,B,DP,X,Y,U SAVE ALL JUST IN CASE
> >> LDX #$094C CLEAR FILE NAME LOCATION
> >> LDA #32
> >> L3 STA ,X+
> >> CMPX #$0954
> >> BNE L3
> >> LDX #$094C FILE NAME LOCATION
> >> L4 JSR $A1B1 GET KEY IN A
> >> TFR A,B SAVE KEY IN B
> >> PSHS B,X,Y
> >> JSR [$A002] ECHO KEY
> >> PULS Y,X,B
> >> TFR B,A GET KEY IN A
> >> CMPA #13 CR?
> >> BEQ NXT2 CR ENDS LOOP
> >> STA ,X+ STORE KEY IN FILE NAME
> >> CMPX #$0954 DONE IF 8 KEYS
> >> BNE L4
> >> NXT2 LDX #$0954 FILE EXTENSION LOCATION
> >> LDA #$42 B
> >> STA ,X+
> >> LDA #$49 I
> >> STA ,X+
> >> LDA #$4E N
> >> STA ,X
> >> LDD #$0200 FILE TYPE = 2, ASCII FLAG = 0
> >> STD $0957
> >> LDX #$0000
> >> STX #$00D3 OFFSET = 0
> >> JSR $CA07 OPEN NEXT AVAIL FILE FOR INPUT
> >> LDD #RET2 RETURN ADDR FOR LOADM RTS
> >> PSHS D
> >> JMP $CFE3 LOADM
> >> RET2 PULS U,Y,X,DP,B,A,CC RESTORE ALL
> >> JMP NEXT RETURN TO FORTH
> >>
> >> This code works fine on a stock CoCo 3, as well as in VCC with a 6809
> >> CPU. It is not elegant, and I don’t think I tried any fancy stuff.
> Don’t
> >> worry about the first few lines of code - they are for linking into
> Color
> >> Forth, and that seem to be fine.
> >>
> >> As far as I can tell, this code does not initiate any disk activity when
> >> the CPU is a 6309, the machine simply goes off into never-never-land.
> >>
> >> Thanks, in advance, for whatever observations or advice you may have to
> >> offer.
> >>
> >
> >
> > The code listing above contains an illegal instruction. In particular:
> >
> > STX #$00D3 OFFSET = 0
> >
> > You can't use an immediate operand with STX. If that is how it actually
> > appears in your source code then it should be fixed. I would be
> surprised
> > that an assembler accepts that without an error or warning.
> >
> > - Darren
> >
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > https://pairlist5.pair.net/mailman/listinfo/coco
>
>
> --
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> Coco at maltedmedia.com
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>
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