I managed to catch some of my code I couldn't find on my hard drive at The
Dig and quickly *groan in advance* "dug in". And I quickly hit some errors:
D:\Stella\DASM212>dasm dismiss.asm -f3 -v2 -omiss.bin
DASM V2.12.04, high level Macro Assembler
(C)Copyright 1988 by Matthew Dillon, All Rights Reserved
Improvements (C)Copyright 1995 by Olaf 'Rhialto' Seibert, All Rights Reserved
Include: dismiss.asm
END OF PASS: 1
Segment--- init-pc init-rpc finl-pc finl-rpc
code f000 ???? 1000 ????
Reasons: 28, 16 Reasoncode: 00002005
Include: dismiss.asm
END OF PASS: 2
Segment--- init-pc init-rpc finl-pc finl-rpc
code f000 ???? 1000 ????
Reasons: 2, 2 Reasoncode: 00000004
Include: dismiss.asm
END OF PASS: 3
Segment--- init-pc init-rpc finl-pc finl-rpc
code f000 ???? 1000 ????
Reasons: 2, 2 Reasoncode: 00000004
Error: source is not resolvable.
D:\Stella\DASM212>
I eyeballed the code, and can't see where I went wrong. I'm pretty sure
this code worked as-is when I was on my Mac back in the day. Pretty simple
stuff -- just moving a two scan missle around the screen. Seems like I've
had similar trouble before and it was just a formatting thing, but I can't
figure out what (I moved the "processor 6502" line all over all ready and
replaced it with the same from nbcombat (which compiles) as well).
Any help would be appreciated and would help keep me from making Homer
something something.
Thanks!
Ruffin Bailey; ------------------------------------------------------------------------
; * Subject: [stella] Distella --> DAsm problem
; * From: Ruffin Bailey <rufbo@xxxxxxxxxxxxx>
; * Date: Fri, 21 Aug 98 13:55:03 -0000
; ------------------------------------------------------------------------
; See original message post for details
; http://www.biglist.com/lists/stella/archives/9808/msg00065.html
; dasm source.s -f3 -osource.bin
; Disassembly of missile.bin aka How to move a missile around your screen.
; Disassembled Sat Aug 15 11:32:54 1998
; Using DiStella v2.0 on a Mac, no less!
;
; Command Line: distella -pafs missile.bin
;
processor 6502
VSYNC = $00
VBLANK = $01
WSYNC = $02
COLUP0 = $06
COLUP1 = $07
COLUPF = $08
COLUBK = $09
CTRLPF = $0A
PF0 = $0D
PF1 = $0E
GRP0 = $1B
GRP1 = $1C
ENAM0 = $1D
ENAM1 = $1E
ENABL = $1F
HMM0 = $22
HMOVE = $2A
CXCLR = $2C
SWCHA = $0280
INTIM = $0284
TIM64T = $0296
ORG $F000
START:
SEI ;2
CLD ;2
LDA #$20 ;2
STA $80 ;3
LDX #$FF ;2
TXS ;2
LDA #$00 ;2
LF00B: STA VSYNC,X ;4
DEX ;2
BNE LF00B ;2
JSR LF0D8 ;6
LF013: JSR LF025 ;6
JSR LF03F ;6
JSR LF044 ;6
JSR LF07D ;6
JSR LF0D0 ;6
JMP LF013 ;3
LF025: LDX #$00 ;2
LDA #$02 ;2
STA WSYNC ;3
STA WSYNC ;3
STA WSYNC ;3
STA VSYNC ;3
STA WSYNC ;3
STA WSYNC ;3
LDA #$2C ;2
STA TIM64T ;4
STA WSYNC ;3
STA VSYNC ;3
RTS ;6
LF03F: LDA #$00 ;2
STA COLUBK ;3
RTS ;6
LF044: LDA #$88 ;2 setting up the colors
STA COLUP0 ;3 P0 is blue
LDA #$36 ;2
STA COLUPF ;3 PF redish (won't see that here, though)
LDA #$D8 ;2
STA COLUP1 ;3 P1 yellow (Sir Not Pictured in this film)
LDA #$00 ;2
STA COLUBK ;3 BK black
LDA #$00 ;2
STA CTRLPF ;3
LDA #$00 ;2
STA HMM0 ;3
LDA SWCHA ;4 SWCHA dissection
BMI LF065 ;2 Player 0 | Player 1
LDY #$F0 ;2 ===============|===============
STY HMM0 ;3 D7 D6 D5 D4 | D3 D2 D1 D0
LF065: ROL ;2 rt lt dn up | rt lt dn up
BMI LF06C ;2
LDY #$10 ;2 I'm using BMI to read D7 of SWCHA
STY HMM0 ;3 (which has been read into the accumulator)
LF06C: ROL ;2 Then rolling the byte to the left and reading the
BMI LF073 ;2 next bit (D6,5,4...) with BMI since the next
INC $80 ;5 bit would now be D7.
INC $80 ;5
LF073: ROL ;2 $80 holds the scan line that the missile
BMI LF07A ;2 will appear on, and since I'm counting up from 1
DEC $80 ;5 in the screen drawing loop, I decrease $80 to move
DEC $80 ;5 the missile up and increase $80 to go down.
LF07A: STA CXCLR ;3
RTS ;6 I assume the HMM0 commands are self-explanatory! ;)
LF07D: LDA INTIM ;4 Here's the screen draw routine.
BNE LF07D ;2
STA WSYNC ;3
STA VBLANK ;3
LDA #$02 ;2
STA CTRLPF ;3
LDX #$01 ;2
STA HMOVE ;3 DON'T FORGET TO HIT HMOVE!! or the object won't move
LF08E: STA WSYNC ;3 horizontally. I might have forgotten that for a while...
INX ;2 causing nearly unbearable psychological pain.
BEQ LF0B7 ;2
CPX $80 ;3
BEQ LF09A ;2
JMP LF08E ;3
LF09A: LDA #$02 ;2
STA ENAM0 ;3 Turn the missile on by putting %00000010 into
STA WSYNC ;3 ENAM0
INX ;2
CPX #$C1 ;2
BEQ LF0B7 ;2
STA WSYNC ;3
INX ;2
CPX #$C1 ;2
BEQ LF0B7 ;2
LDA #$00 ;2
STA ENAM0 ;3 Turn it off by putting zero into ENAM0. Here, the missile
STA WSYNC ;3 is two scans tall. Cute little bugger.
LF0B2: INX ;2
CPX #$C1 ;2
BNE LF0B2 ;2
LF0B7: LDA #$02 ;2
STA WSYNC ;3
STA VBLANK ;3
LDY #$00 ;2
STY PF0 ;3
STY PF1 ;3
STY PF1 ;3
STY GRP0 ;3
STY GRP1 ;3
STY ENAM0 ;3
STY ENAM1 ;3
STY ENABL ;3
RTS ;6
LF0D0: LDX #$1E ;2
LF0D2: STA WSYNC ;3
DEX ;2
BNE LF0D2 ;2
RTS ;6
LF0D8: LDA #$00 ;2
STA $90 ;3
RTS ;6
org $FFFC
.word Start
.word Start
