Game of Life 32b
From SizeCoding
This writeup is still in the works! Come back later to get information on all the mean tricks ;)
Contents
Original version : 65 bytes
We'll start with the old 65 bytes version and bring it down to 32 bytes.
; http://read.pudn.com/downloads208/sourcecode/asm/981812/LIFE65.ASM__.htm
; Life simulator, 72 bytes - Vladislav Kaipetsky and Tenie Remmel
; 65 bytes - Mark Andreas
; If no args, regs on startup are:
; AX = BX = 0000h
; SI = IP = 0100h
; DI = SP = FFFEh
IDEAL
MODEL TINY
P386
CODESEG
ORG 100h
Start: int 1ah ; ah=00: cx=hours, dx=tic counter
mov al,13h ; Set mode 13h
int 10h
xchg dx,ax
push 09000h ; DS = last 64K segment
pop ds
push 0A000h ; ES = video memory
pop es
; BX is already zero
RandLoop:
rol ax,1 ; Generate random number
adc [bx],al
dec bx
jnz RandLoop
; BX will not be equal to 3 the first time this loop is executed, but
; it will be for all other times. As SI = 0100h and DI = FFFEh on
; startup, SI - DI will be equal to 258.
LifeLoop:
xchg cx,ax
AccLoop:
add cl,[di+bx-64] ; Add in this column
add cl,[si+bx-2]
add cl,[si+bx+318]
dec bx ; Loop back
jnz AccLoop
mov al,[si] ; Get center cell, set pixel
stosb
stc ; 3 = birth, 4 = stay (tricky):
rcr al,cl ; 1.00?0000x --> 0.0x100?00 (rcr 3)
and al,20h ; ^carry | ^
; +---> 0.00x100?0 (rcr 4)
or [si-1],al ; Add in new cell ^
shr [byte di-65],5 ; Shift previous value
mov bl,3 ; 3 iterations in AccLoop
inc si ; Loop while not zero
jnz LifeLoop
mov ah,1 ; Check for key
int 16h
jz LifeLoop ; Loop if no key
xchg ax,bx ; Set text mode
int 10h
ret ; Return
End Start
Remove key handler and RNG : 44 bytes
Start:
mov al,93h ; Set mode 13h
int 10h
push 09000h ; DS = last 64K segment
pop ds
push 0A000h ; ES = video memory
pop es
; BX is already zero
LifeLoop:
xchg cx,ax
AccLoop:
add cl,[di+bx-64] ; Add in this column
add cl,[si+bx-2]
add cl,[si+bx+318]
dec bx ; Loop back
jnz AccLoop
;mov al,[si] ; Get center cell, set pixel
lodsb
stosb
stc ; 3 = birth, 4 = stay (tricky):
rcr al,cl ; 1.00?0000x --> 0.0x100?00 (rcr 3)
and al,20h ; ^carry | ^
; +---> 0.00x100?0 (rcr 4)
or [si-1],al ; Add in new cell ^
shr [byte di-65],5 ; Shift previous value
mov bl,3 ; 3 iterations in AccLoop
; inc si ; Loop while not zero
jmp short LifeLoop
Switching to Textmode : 39 bytes
push 0xb800
pop ds
LifeLoop:
stc ; 3 = birth, 4 = stay (tricky):
rcr al,cl ; 1.00?0000x --> 0.0x100?00 (rcr 3)
and al,20h ; ^carry | ^
or [si-2],al ; Add in new cell ^
shr byte [si-160-6],5 ; Shift previous value
mov bl,6
xchg cx,ax
AccLoop: add cl,[si+bx-160-4] ; Add in this column
add cl,[si+bx-4]
add cl,[si+bx+160-4]
dec bx ; Loop back
dec bx ; Loop back
jnz AccLoop
lodsw
jmp LifeLoop
TODO
