Game of Life x86

life.asm

    .8086
    .MODEL tiny
    .CODE
    org 100h

start:
    mov ax,0013h
    int 10h

    mov al,MEMORY_MODE
    mov ah,06h
    mov dx,SC_INDEX
    out dx,ax
    mov al,UNDERLINE_LOCATION
    mov ah,00h
    mov dx,CRTC_INDEX
    out dx,ax
    mov al,MODE_CONTROL
    mov ah,0e3h
    out dx,ax

    mov ax,01h ; c
    push ax
    mov ax,64h ; y
    push ax
    mov ax,100h ; x
    push ax
    mov ax,0h ; page
    push ax
    call set_pixel
    mov ax,01h ; c
    push ax
    mov ax,64h ; y
    push ax
    mov ax,101h ; x
    push ax
    mov ax,0h ; page
    push ax
    call set_pixel
    mov ax,01h ; c
    push ax
    mov ax,64h ; y
    push ax
    mov ax,102h ; x
    push ax
    mov ax,0h ; page
    push ax
    call set_pixel

mainloop:
    ; set vga page
    mov dx,CRTC_INDEX
    mov ax,vgapage1
    mov al,START_REG_HIGH
    out dx,ax
    mov dx,CRTC_INDEX
    mov ax,vgapage1
    mov cl,8
    shl ax,cl
    mov al,START_REG_LOW
    out dx,ax
    ; do vsync
loop1:
    mov dx,INPUT_STATUS
    in al,dx
    and al,08h
    jnz loop1
loop2:
    mov dx,INPUT_STATUS
    in al,dx
    and al,08h
    jz loop2

    ; update game state
    call update_game
    mov ax,vgapage1
    mov bx,vgapage2
    mov vgapage2,ax
    mov vgapage1,bx
    mov ah,01h
    dec frames
    jz exit
    int 16h
    jz mainloop

exit:
    mov ax,0003h
    int 10h
    mov ax,4c00h
    int 21h

update_game proc
    push bp
    mov bp,sp

    mov ax,max_y
    mov line,ax
loop_lines:
    mov ax,max_x
    mov column,ax
loop_columns:

    call acc_neighbors

    dec column
    jnz loop_columns
    dec line
    jnz loop_lines

    pop bp
    ret
endp update_game

acc_neighbors proc
    push bp
    mov bp,sp

    ; read current pixel (alive or dead)
    mov ax,line
    mov pixel_y,ax
    mov ax,column
    mov pixel_x,ax
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    mov current_pixel,al

    ; accumulate all 8 neighbors
    mov neighbors,0
    ; -1,-1
    mov ax,line
    mov pixel_y,ax
    mov ax,column
    mov pixel_x,ax
    dec pixel_y
    dec pixel_x
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al
    ; 0,-1
    inc pixel_x
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al
    ; 1,-1
    inc pixel_x
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al
    ; 1,0
    inc pixel_y
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al
    ; -1,0
    dec pixel_x
    dec pixel_x
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al
    ; -1,1
    inc pixel_y
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al
    ; 0,1
    inc pixel_x
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al
    ; 1,1
    inc pixel_x
    push pixel_y
    push pixel_x
    push vgapage1
    call get_pixel
    add neighbors,al

    pop bp
    ret
endp acc_neighbors

set_pixel proc
    arg vgapage:word, x:word, y:word, c:byte

    push bp
    mov bp,sp
    push ds
    ;select VGA plane
    mov cx,x
    and cl,3
    mov ah,1
    shl ah,cl
    mov al,MAP_MASK
    mov dx,SC_INDEX
    out dx,ax

    ;compute vga offset
    mov ax,y
    mov bx,ax
    mov cl,8
    shl ax,cl
    mov cl,6
    shl bx,cl
    add ax,bx
    mov cl,2
    shr ax,cl
    mov bx,x
    shr bx,cl
    add ax,bx
    add ax,vgapage

    mov dx,VGA_MEM
    mov ds,dx
    mov di,ax
    mov al,c
    mov ds:[di],al

    pop ds
    pop bp
    ret
set_pixel endp

get_pixel proc
    arg vgapage:word, x:word, y:word

    push bp
    mov bp,sp
    push ds
    ;select VGA plane
    mov cx,x
    and cl,3
    mov ah,1
    shl ah,cl
    mov al,MAP_MASK
    mov dx,SC_INDEX
    out dx,ax

    ;compute vga offset
    mov ax,y
    mov bx,ax
    mov cl,8
    shl ax,cl
    mov cl,6
    shl bx,cl
    add ax,bx
    mov cl,2
    shr ax,cl
    mov bx,x
    shr bx,cl
    add ax,bx
    add ax,vgapage

    mov dx,VGA_MEM
    mov ds,dx
    mov di,ax
    mov al,ds:[di]

    pop ds
    pop bp
    ret
get_pixel endp

neighbors db 0
current_pixel db 0
column dw 0
line dw 0
pixel_x dw 0
pixel_y dw 0
frames   dw 1000
vgapage1 dw 0
vgapage2 dw 16000
max_x dw 319
max_y dw 199

SC_INDEX		 equ 03c4h
SC_DATA			 equ 03c5h
CRTC_INDEX		 equ 03d4h
CRTC_DATA		 equ 03d5h
MEMORY_MODE		 equ 04h
UNDERLINE_LOCATION	 equ 014h
CRTC_INDEX		 equ 03d4h
INPUT_STATUS		 equ 03dah
MODE_CONTROL		 equ 017h
MAP_MASK		 equ 02h
VGA_MEM			 equ 0A000h
START_REG_HIGH		 equ 0ch
START_REG_LOW		 equ 0dh

    end start

I think you need to pop the function parameters than you are pushing. Apparently ret can take a number of bytes to pop off the stack

Yes, indeed. We established that in the YouTube comments as well. :)