我做了一个运行这个十六进制代码的AsmProgram:
9D95:00
9D96:00
9D97:00
9D98:00
9D99:0E
9D9A:09
9D9B:3E
9D9C:00
9D9D:EF
9D9E:5D
9D9F:49
9DA0:06
9DA1:80
9DA2:A8
9DA3:CB
9DA4:47
9DA5:CB
9DA6:0F
9DA7:CA
9DA8:95
9DA9:9D
9DAA:10
9DAB:F9
9DAC:C9
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它应该等到按下+按钮然后结束,但它似乎不起作用.
这是你的原始代码,据我所知:
.org 9D95h
nop
nop
nop
nop
ld c, 09h ; ???
ld a, 0 ; ???
rst 28h ; \
.db 5Dh ; > DispTail, destroys AF, BC, DE, HL, aka
.db 49H ; / undefined behaviour in this case (we don't
; know what A contains)
ld b, 80h ; B <- 0x80
xor b ; A <- A XOR B
bit 0, a ; A[0] == 0, Z is set, if so
loop: rrc a ; rotate right A, C <- A[0]
jp z, 9D95h ; Jump to 9D95, if Z set
djnz loop ; Decrease B, jump if not zero to loop
ret ; After 128 jumps, returns
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总而言之,他们的密钥代码检查部分从get go开始是错误的(调用错误的ROM调用并且过度复杂).这似乎有用:
.org 9D95h
rst 28h ; \
.db 72h ; > Call GetKey, A <- key code
.db 49h ; /
cp 80h ; Compare A with immediate value 0x80 (subtract),
; key code for [+] is 0x80
jp nz, 9D95h ; Jump if Z is not set (was not 0x80)
ret ; return
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或以十六进制:
EF 72 49 FE 80 C2 95 9D C9
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