It seems to me that 6502's ASM linker screws the logical sequence of my code that way so I can't explain why. At the lines marked with ( <-- O) the address pointer becoming offset by 2 bytes. So it jumps at the line marked with ( <-- 1). Then, every data pointer at the lines marked with ( <-- S) has starting address offset in 4 bytes. As the result, part of a message is not being displayed.
Please share with me your thoughts of what I possibly doing wrong here.
main.asm
.org $2000
.macro asc Arg
.repeat .strlen(Arg), I
.byte .strat(Arg, I) | $80
.endrep
.endmacro
.define asc2(Arg) asc Arg
.macro ascz Arg
.repeat .strlen(Arg), I
.byte .strat(Arg, I) | $80
.endrep
.byte $00
.endmacro
.macro asccr Arg
.repeat .strlen(Arg), I
.byte .strat(Arg, I) | $80
.endrep
.byte $8d
.endmacro
COUT = $FDED
CHR_CR = $8D
PTR = $06
VTAB = $FC22
CH = $24
CV = $25
cld
ldx #$FF
txs
lda #$69
sta $03F2
lda #$ff
sta $03F3
eor #$a5
sta $03F4
jsr $FC58
jsr $FE84
jsr $FE89
jsr $FE93
lda $BF98
and #$A8
cmp #$A8
bcs @ErrEnvMachine
clc
lda #$02
bit $BF98
beq @ErrEnv80Col
@ErrEnvMachine:
lda #$01
jmp ERRHNDLR
@ErrEnv80Col:
lda #$02
jmp ERRHNDLR
ERRHNDLR:
cmp #$01
beq @ErrEnvMachine
cmp #$02
beq @ErrEnv80Col
bne @ErrGeneric
@ErrEnvMachine:
lda #<MErrEnvM
sta PTR
lda #>MErrEnvM
sta PTR+1
beq PrintErrMsg
@ErrEnv80Col:
lda #<MErr80Col
sta PTR
lda #>MErr80Col
sta PTR+1
beq PrintErrMsg
@ErrGeneric:
lda #<MErrgen
sta PTR
lda #>MErrgen
sta PTR+1
PrintErrMsg:
ldx #$0
ldy #$17
jsr GOTOXY
ldy #$00
: lda (PTR),y
beq :+
jsr COUT
iny
bne :-
: jmp EXIT
GOTOXY:
stx CH
sty CV
jsr VTAB
rts
EXIT:
dec $03F4
jsr $BF00
.byte $65
.word PARMTABLE
PARMTABLE:
.byte $04
.byte $00
.word $0000
.byte $00
.word $0000
MErrEnvM:
ascz "PROG WON'T RUN"
MErr80Col:
ascz "PROG REQUIRES 80-COL MODE"
MErrgen:
ascz "AN ERROR OCCURRED"
disk image PROG.po.zip
Thanks!
PS: This error doesn't depend on the "cheap"/unnamed labels, the logic sequence or the compiler.
UPDATE #1:
build.sh
#!/usr/bin/env bash
ca65 --cpu 6502 -t apple2 -l main.lst main.asm -o main.o
ld65 -o PROG -C main.cfg -m main.map main.o
...
exit 0
main.cfg
SYMBOLS {
__FILETYPE__: type = weak, value = $00FF; # ProDOS file type (SYS)
__STACKSIZE__: type = weak, value = $0800; # 2k stack
}
MEMORY {
RAM: file = %O, define = yes, start = $2000, size = $BF00 - $2000, fill=yes;
BSS: file = "", start = __RAM_LAST__, size = $BF00 - __RAM_LAST__;
}
SEGMENTS {
CODE: load = RAM, type = ro;
RODATA: load = RAM, type = ro;
BSS: load = RAM, type = bss;
}
UPDATE #2:
Disassembled as:
da65 --cpu 6502 --start-addr=$2000 -o PROG.dasm PROG
Output:
; da65 V2.18 - N/A
; Created: 2023-10-22 17:45:36
; Input file: PROG
; Page: 1
.setcpu "6502"
L0004 := $0004
L203A := $203A
L2076 := $2076
L207E := $207E
cld
ldx #$FF
txs
lda #$69
sta $03F2
lda #$FF
sta $03F3
eor #$A5
sta $03F4
jsr LFC58
jsr LFE84
jsr LFE89
jsr LFE93
lda LBF98
and #$A8
cmp #$A8
bcs L6130
clc
lda #$02
bit LBF98
beq L6135
L6130: lda #$01
jmp L203A
L6135: lda #$02
jmp L203A
cmp #$01
beq L6144
cmp #$02
beq L614E
bne L6158
L6144: lda #$8E
sta $06
lda #$20
sta $07
beq L6160
L614E: lda #$9D
sta $06
lda #$20
sta $07
beq L6160
L6158: lda #$B7
.byte $85
L615B: asl $A9
jsr $0785
L6160: ldx #$00
L6162: ldy #$17
jsr L2076
ldy #$00
L6169: lda ($06),y
beq L6173
jsr LFDED
iny
L6171: bne L6169
L6173: jmp L207E
stx $24
sty $25
jsr LFC22
rts
dec $03F4
jsr LBF00
adc $87
jsr L0004
brk
brk
brk
brk
brk
bne L6162
.byte $CF
.byte $C7
ldy #$D7
.byte $CF
dec LD4A7
ldy #$D2
cmp $CE,x
brk
bne L6171
.byte $CF
.byte $C7
ldy #$D2
cmp $D1
cmp $C9,x
.byte $D2
cmp $D3
ldy #$B8
bcs L615B
.byte $C3
.byte $CF
cpy LCDA0
.byte $CF
cpy $C5
brk
cmp ($CE,x)
ldy #$C5
.byte $D2
.byte $D2
.byte $CF
.byte $D2
ldy #$CF
.byte $C3
.byte $C3
cmp $D2,x
.byte $D2
cmp $C4
...
brk
UPDATE #3:
java -jar acx-1.8.0.jar create -d PROG.po --prodos-order --name=PROG --format=ProDOS_2_4_2.dsk --prodos --size=140kb
java -jar acx-1.8.0.jar import --dos PROG --disk=PROG.po --name=PROG.SYSTEM -t=sys --aux=8192
java -jar acx-1.8.0.jar unlock -d PROG.po BASIC.SYSTEM
java -jar acx-1.8.0.jar del -d PROG.po BASIC.SYSTEM
java -jar acx-1.8.0.jar lock -d PROG.po PROG.SYSTEM
Alright. There are few points to mention, based on this discussion on GitHub.
Many thanks to all who helped in finding the answers.