base:turbo250_disassembled
Turbo 250 Mr.Z Disassembled
Written by FTC
This was disassembled the other day using IDA Pro (an old but useable freeware dos version available at 6502.org) and then converted it into ACME format. The process involved “decoding” some EOR'ed blocks of code, and therefore slight changes had to be made to the startup code. (To be able to convert all parts of the program into readable assembler source rather than EOR'ed data.)
The source is hardly labelled at all, but I guess it could still be nice to have a look at for some people. I might update it sometime, but don't count on it.
I just couldn't resist looking under the hood of this extremely classic piece of software. ;)
;============================================================================
* = $0801
basic_startup:
!byte $10 ;
!byte 8 ;
!byte $A ;
!byte 0 ;
!byte $9E ;
!byte $32 ; 2
!byte $30 ; 0
!byte $36 ; 6
!byte $36 ; 6
!byte $20 ;
eorval1: !byte $4D ; M
eorval2: !byte $52 ; R
eorval3: !byte $2E ; .
eorval4: !byte $5A ; Z
!byte 0 ;
!byte 0 ;
!byte 0 ;
;============================================================================
; ldx lamerprotection
; stx $fb
ldx #0
printmsg: ; code xref: 0824j
lda string,x ;lda string-$4d,x ;$4d = EOR instructino at lamerprotection
beq lamerprotection ;bypass message
jsr $e716
; eor $fb
; sta $fb
inx
bne printmsg
lamerprotection: ; code xref: 081aj
; data xref: 0812r
eor #$ff ; a=ff x=fa y=90 fb=d5
tay
iny
ldx #$ff
txs
ldx #$55
copy1: ; code xref: 083dj
lda code1,y ; y=0
; eor $fb ; fb=d5
; eor $7b6,x ; 080d=$4d
sta $2a7,y
iny
cpy #$58
bne copy1
ldy #0
copy2: ; code xref: 084fj
lda code2,y
; eor $fb ; fb=d5
; eor $7b7,x ; 080e=52
sta $334,y
iny
cpy #$c7
bne copy2
ldy #0
copy3: ; code xref: 0861j
lda code3,y
; eor $fb ; fb=d5
; eor $7b8,x ; 080f=2e
sta $10b,y
iny
cpy #$97
bne copy3
ldy #0
copy4: ; code xref: 0873j
lda code4,y
; eor $fb ; fb=d5
; eor $7b9,x ; 0810=5a
sta $ff3b,y
iny
cpy #$c5
bne copy4
lda #$a7
ldx #2
sta $308 ; basic caracter dispatch
stx $309
jmp $a474 ; restart basic
;============================================================================
string: !byte $93 ; “
!byte $8E ; Ž
!byte $B0 ; °
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $AE ; ®
!byte $D ;
!byte $C2 ; Â
!byte $20 ;
!byte $54 ; T
!byte $55 ; U
!byte $52 ; R
!byte $42 ; B
!byte $4F ; O
!byte $20 ;
!byte $32 ; 2
!byte $35 ; 5
!byte $30 ; 0
!byte $20 ;
!byte $42 ; B
!byte $59 ; Y
!byte $20 ;
!byte $4D ; M
!byte $52 ; R
!byte $2E ; .
!byte $5A ; Z
!byte $20 ;
!byte $C2 ; Â
!byte $D ;
!byte $C2 ; Â
!byte $43 ; C
!byte $41 ; A
!byte $4E ; N
!byte $20 ;
!byte $48 ; H
!byte $41 ; A
!byte $4E ; N
!byte $44 ; D
!byte $4C ; L
!byte $45 ; E
!byte $20 ;
!byte $50 ; P
!byte $52 ; R
!byte $4F ; O
!byte $47 ; G
!byte $52 ; R
!byte $41 ; A
!byte $4D ; M
!byte $53 ; S
!byte $C2 ; Â
!byte $D ;
!byte $C2 ; Â
!byte $42 ; B
!byte $45 ; E
!byte $54 ; T
!byte $57 ; W
!byte $45 ; E
!byte $45 ; E
!byte $4E ; N
!byte $20 ;
!byte $24 ; $
!byte $30 ; 0
!byte $38 ; 8
!byte $30 ; 0
!byte $31 ; 1
!byte $2D ; -
!byte $24 ; $
!byte $46 ; F
!byte $46 ; F
!byte $33 ; 3
!byte $42 ; B
!byte $C2 ; Â
!byte $D ;
!byte $AB ; «
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $B3 ; ³
!byte $D ;
!byte $C2 ; Â
!byte $5F ; _
!byte $4C ; L
!byte $20 ;
!byte $20 ;
!byte $20 ;
!byte $20 ;
!byte $20 ;
!byte $20 ;
!byte $20 ;
!byte $20 ;
!byte $4C ; L
!byte $4F ; O
!byte $41 ; A
!byte $44 ; D
!byte $20 ;
!byte $50 ; P
!byte $52 ; R
!byte $4F ; O
!byte $47 ; G
!byte $C2 ; Â
!byte $D ;
!byte $C2 ; Â
!byte $5F ; _
!byte $53 ; S
!byte $20 ;
!byte $28 ; (
!byte $4E ; N
!byte $41 ; A
!byte $4D ; M
!byte $45 ; E
!byte $29 ; )
!byte $20 ;
!byte $53 ; S
!byte $41 ; A
!byte $56 ; V
!byte $45 ; E
!byte $20 ;
!byte $50 ; P
!byte $52 ; R
!byte $4F ; O
!byte $47 ; G
!byte $C2 ; Â
!byte $D ;
!byte $AD ;
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $C3 ; Ã
!byte $BD ; ½
!byte 0 ;
;##################################################################################
;##################################################################################
;##################################################################################
code1:
!pseudopc $2a7 {
;============================================================================
JSR $73
BEQ loc_0_2B0
CMP #$5F
BEQ loc_0_2B3
loc_0_2B0: ; CODE XREF: 02AAj
JMP $A7E7
;============================================================================
loc_0_2B3: ; CODE XREF: 02AEj
JSR $73
CMP #$4C
BEQ loc_0_2C1
CMP #$53
BEQ loc_0_2C4
JMP $AF08
;============================================================================
loc_0_2C1: ; CODE XREF: 02B8j
JMP loc_0_111
;============================================================================
loc_0_2C4: ; CODE XREF: 02BCj
JMP loc_0_120
;============================================================================
loc_0_2C7: ; CODE XREF: 011Aj
LDX #0
STX $A
STX $93
STX $90
loc_0_2CF: ; CODE XREF: 02DAj
JSR loc_0_334
LDA $AB
CMP #1
BEQ loc_0_2DC
CMP #2
BNE loc_0_2CF
loc_0_2DC: ; CODE XREF: 02D6j
DEC $B3
JSR $F750
INC $B3
JSR $A82C
JSR $F5D2
JSR loc_0_355
LDA $BD
EOR $D7
BEQ loc_0_2F6
LDA #$FF
STA $90
loc_0_2F6: ; CODE XREF: 02F0j
JSR $F5A9
JSR $E195
JMP $A7AE
;============================================================================
}
;##################################################################################
;##################################################################################
;##################################################################################
code2:
!pseudopc $334 {
;============================================================================
loc_0_334: ; CODE XREF: 0339j
JSR sub_0_388
CMP #0
BEQ loc_0_334
STA $AB
loc_0_33D: ; CODE XREF: 0346j
JSR sub_0_3B6
STA $AC,Y
INY
CPY #5
BNE loc_0_33D
loc_0_348: ; CODE XREF: 0351j
JSR sub_0_3B6
STA $23C,Y
INY
CPY #$15
BNE loc_0_348
BEQ sub_0_37C
loc_0_355:
JSR sub_0_388
loc_0_358: ; CODE XREF: 0373j
JSR sub_0_3B6
LDA #4
STA 1
LDA $BD
STA ($AC),Y
LDA #7
STA 1
LDA $BD
EOR $D7
STA $D7
JSR $FCDB
JSR $FCD1
BCC loc_0_358
JSR sub_0_3B6
JSR sub_0_3E0
INY
;############################################################################
; S u b r o u t i n e
sub_0_37C: ; CODE XREF: 017Cp 0353j
STY $C0
CLI
CLC
LDA #0
STA $2A0
JMP $FC93
; End of function sub_0_37C
;############################################################################
; S u b r o u t i n e
sub_0_388: ; CODE XREF: 0334p 0355p
JSR loc_0_10B
JSR sub_0_3E0
STY $D7
LDA #7
STA $DD06
LDX #1
loc_0_397: ; CODE XREF: sub_0_388+18j
; sub_0_388+25j
JSR sub_0_3C9
ROL $BD
LDA $BD
CMP #2
BNE loc_0_397
LDY #9
loc_0_3A4: ; CODE XREF: sub_0_388+21j
JSR sub_0_3B6
CMP #2
BEQ loc_0_3A4
loc_0_3AB: ; CODE XREF: sub_0_388+2Bj
CPY $BD
BNE loc_0_397
JSR sub_0_3B6
DEY
BNE loc_0_3AB
RTS
; End of function sub_0_388
;############################################################################
; S u b r o u t i n e
sub_0_3B6: ; CODE XREF: 033Dp 0348p 0358p 0375p
; ...
LDA #8
STA $A3
loc_0_3BA: ; CODE XREF: sub_0_3B6+Ej
JSR sub_0_3C9
ROL $BD
NOP
NOP
NOP
DEC $A3
BNE loc_0_3BA
LDA $BD
RTS
; End of function sub_0_3B6
;############################################################################
; S u b r o u t i n e
sub_0_3C9: ; CODE XREF: sub_0_388+Fp sub_0_3B6+4p
LDA #$10
loc_0_3CB: ; CODE XREF: sub_0_3C9+5j
BIT $DC0D
BEQ loc_0_3CB
LDA $DD0D
STX $DD07
PHA
LDA #$19
STA $DD0F
PLA
LSR
LSR
RTS
; End of function sub_0_3C9
;############################################################################
; S u b r o u t i n e
sub_0_3E0: ; CODE XREF: 0168p 0378p sub_0_388+3p
LDY #0
STY $C0
LDA $D011
AND #$EF
STA $D011
loc_0_3EC: ; CODE XREF: sub_0_3E0+Dj sub_0_3E0+10j
DEX
BNE loc_0_3EC
DEY
BNE loc_0_3EC
SEI
RTS
; End of function sub_0_3E0
;============================================================================
irq:
LDA #$37 ; '7'
STA 1
JMP $FE69
;============================================================================
}
;##################################################################################
;##################################################################################
;##################################################################################
code3: ;!bin "block3.PRG",,2
!pseudopc $10b {
;============================================================================
loc_0_10B:
JSR $F817
JMP $A82C
;============================================================================
loc_0_111:
JSR $73
BEQ loc_0_11A
CMP #$3A
BNE loc_0_11D
loc_0_11A: ; CODE XREF: 0114j
JMP loc_0_2C7
;============================================================================
loc_0_11D: ; CODE XREF: 0118j
JMP $AF08
;============================================================================
loc_0_120:
LDX $37
LDY $38
STX $FB
STY $FC
LDX $2D
LDY $2E
STX $FD
STY $FE
LDX #$F8
LDY #7
STX $37
STY $38
LDX #$E8
LDY #7
STX $2D
STY $2E
JSR $A660
LDX #$82
LDY #1
STX $302
STY $303
JSR $73
JSR $E1D4
LDX #5
STX $AB
DEX
loc_0_158: ; CODE XREF: 015Dj
LDA $2A,X
STA $AB,X
DEX
BNE loc_0_158
JSR $F838
JSR $A82C
JSR $F68F
JSR sub_0_3E0
SEI
LDA #$7F
STA $DD0D
LDA #4
STA 1
JSR loc_0_FF3B
LDA #7
STA 1
JSR sub_0_37C
JMP $A474
;============================================================================
LDA #$83
STA $302
LDA #$A4
STA $303
LDA $FB
STA $37
LDA $FC
STA $38
LDA $FD
STA $2D
LDA $FE
STA $2E
JSR $A660
JMP ($302)
;============================================================================
}
;##################################################################################
;##################################################################################
;##################################################################################
code4:
!pseudopc $ff3b {
;============================================================================
loc_0_FF3B:
LDA $FD
STA $AE
LDA $FE
STA $AF
JSR sub_0_FFAB
LDA $B9
LDA #2
NOP
DEX
JSR sub_0_FFCB
LDX #8
loc_0_FF51: ; CODE XREF: FF5Dj
LDA $AC,Y
JSR sub_0_FFCB
LDX #6
INY
CPY #5
NOP
BNE loc_0_FF51
LDY #0
LDX #4
loc_0_FF63: ; CODE XREF: FF74j
LDA ($BB),Y
CPY $B7
BCC loc_0_FF6C
LDA #$20
DEX
loc_0_FF6C: ; CODE XREF: FF67j
JSR sub_0_FFCB
LDX #5
INY
CPY #$BB
BNE loc_0_FF63
LDA #2
STA $AB
JSR sub_0_FFAB
TYA
JSR sub_0_FFCB
STY $D7
LDX #7
NOP
loc_0_FF86: ; CODE XREF: FF9Dj
LDA ($AC),Y
JSR sub_0_FFCB
LDX #3
INC $AC
BNE loc_0_FF95
INC $AD
DEX
DEX
loc_0_FF95: ; CODE XREF: FF8Fj
LDA $AC
CMP $AE
LDA $AD
SBC $AF
BCC loc_0_FF86
loc_0_FF9F: ; CODE XREF: FFA7j
LDA $D7
JSR sub_0_FFCB
LDX #7
DEY
BNE loc_0_FF9F
INY
RTS
;############################################################################
; S u b r o u t i n e
sub_0_FFAB: ; CODE XREF: FF43p FF7Ap
LDY #0
loc_0_FFAD: ; CODE XREF: sub_0_FFAB+Cj
; sub_0_FFAB+12j
LDA #2
JSR sub_0_FFCB
LDX #7
DEY
CPY #9
BNE loc_0_FFAD
LDX #5
DEC $AB
BNE loc_0_FFAD
loc_0_FFBF: ; CODE XREF: sub_0_FFAB+1Bj
TYA
JSR sub_0_FFCB
LDX #7
DEY
BNE loc_0_FFBF
DEX
DEX
RTS
; End of function sub_0_FFAB
;############################################################################
; S u b r o u t i n e
sub_0_FFCB: ; CODE XREF: FF4Cp FF54p FF6Cp FF7Ep
; ...
STA $BD
EOR $D7
STA $D7
LDA #8
STA $A3
loc_0_FFD5: ; CODE XREF: sub_0_FFCB+1Fj
ASL $BD
LDA 1
AND #$F7
JSR sub_0_FFED
LDX #$11
NOP
ORA #8
JSR sub_0_FFED
LDX #$E
DEC $A3
BNE loc_0_FFD5
RTS
; End of function sub_0_FFCB
;############################################################################
; S u b r o u t i n e
sub_0_FFED: ; CODE XREF: sub_0_FFCB+10p
; sub_0_FFCB+18p sub_0_FFED+1j
DEX
BNE sub_0_FFED
BCC loc_0_FFF7
LDX #$B
loc_0_FFF4: ; CODE XREF: sub_0_FFED+8j
DEX
BNE loc_0_FFF4
loc_0_FFF7: ; CODE XREF: sub_0_FFED+3j
STA 1
RTS
; End of function sub_0_FFED
;============================================================================
;Interrupt handler pointers which ends up at $fffa - $ffff
!WORD irq
!WORD irq
!WORD irq
}
base/turbo250_disassembled.txt · Last modified: 2015-04-17 04:34 by 127.0.0.1