Snake Non-Optimized

start:
    mov r10, 0
    mov r11, 1
    mov sp, 0x0200
    send r10, 0x200F
;terminal&input : port 0
;random source : port 1
;r4: head's position
;r5: tail's position
;r6: apple's position
mov r4, map
add r4, 19
mov r5, map
add r5, 17
jmp apple
head:
    recv r0, r10
    add r0, h_table
    jmp [r0]
chkapple:
    cmp r4, r6
    je apple
tale:
    mov r0, [r5]
    add r0, t_table
    mov [r5], 0
    jmp [r0]

h_up:
    mov r1, [r4-16]
    jnz gameover
    mov [r4], 3
    sub r4, 16
    mov r2, r4
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x7F
    jmp chkapple
h_down:
    mov r1, [r4+16]
    jnz gameover
    mov [r4], 4
    add r4, 16
    mov r2, r4
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x7F
    jmp chkapple
h_left:
    mov r1, [r4-1]
    jnz gameover
    mov [r4], 1
    sub r4, 1
    mov r2, r4
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x7F
    jmp chkapple
h_right:
    mov r1, [r4+1]
    jnz gameover
    mov [r4], 2
    add r4, 1
    mov r2, r4
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x7F
    jmp chkapple



t_up:
    mov r2, r5
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x20
    sub r5, 16
    jmp head
t_down:
    mov r2, r5
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x20
    add r5, 16
    jmp head
t_left:
    mov r2, r5
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x20
    sub r5, 1
    jmp head
t_right:
    mov r2, r5
    sub r2, map
    or r2, 0x1000
    send r10, r2
    send r10, 0x20
    add r5, 1
    jmp head

apple:
    recv r0, r11
    and r0, 0xFF
    cmp r0, 0xBF
    ja apple
    add r0, map
    mov r1, [r0]
    jnz apple
    mov r6, r0
    sub r0, map
    or r0, 0x1000
    send r10, r0
    send r10, 0x30
    jmp head

gameover:
    hlt



h_table:
    %dw 0, h_left, h_right, h_up, h_down
t_table:
    %dw 0, t_left, t_right, t_up, t_down

map:
    %dw 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
    %dw 1,2,2,2,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1
    %dw 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1