emblem.asm

bits 16
section .text
global _start
_start:
  mov ax, 0x13 
  int 0x10     
  push 0xa000
  pop ds
  xor dx, dx 
  xor bp, bp 
  mov al, black      
  mov bx, vga 
  call bg
  mov ax, 40*1 
  call hline
  mov ax, 40*2
  call hline
  mov ax, 40*3
  call hline
  mov ax, 40*4
  call hline
  mov ax, 30
  call vline
  mov ax, 30*3+10
  call vline
  mov ax, 30*6+10
  call vline
  xor ax, ax
  not ax
  sub ax, 60
  call vline
  mov word [cloc], 0x0f0f*4+80
  call circle
  mov word [cloc], 0x0f0f*7+100
  call circle
  mov word [cloc], 0x0f0f*11+100+80+30
  call circle
  mov word [cloc], 0x0f0f*11+100+80+10+(320/3)
  call circle
  mov word [cloc], 0x0f0f*11+100+80+10+(320/3)*2-40
  call circle
  sleep: jmp sleep
circle:
  xor dx, dx
  xor bp, bp
  mov ax, rad
  mov bx, ax
  mov si, 1
  mov di, (((rad*rad)-rad)/2)-1
  lea cx, [bx+si]
cia:
  pusha
  sub ax, rad
  mov cl, 4
cib:
  imul di, ax, 320
  add di, word [cloc]
  mov byte [di+bx], red
  sub di, word [cloc]
  xchg ax, bx
  imul di, ax, 320
  add di, word [cloc]
  mov byte [di+bx], white
  sub di, word [cloc]
  neg ax
  add ax, (rad*2)
  loop cib
  popa
  add bp, si
  inc si
  lea dx, [bp+di-((rad*rad)/2)]
  dec bx
  cmp dx, ax
  ja cia
  sub di, cx
  dec cx
  inc ax
  cmp si, cx
  jna cia
  xor ax, ax
  mov ax, [cloc]
  ret
bg:
  dec bx
  mov byte [bx], al
  jnz bg
  ret
vline:
  mov es, word[vga]
  mov di, 320*40
  add di, ax 
  mov ax, white 
  mov cx, 120
vplot:
  mov [di], al
  add di, 320
  loop vplot
  ret
hline:
  push ax 
  mov es, word [vga]
  mov ax, 320
  pop bx 
  mul bx 
  mov di, ax 
  mov cx, 320-90 
  mov ax, white
  add di, 30
hplot:
  mov byte [di], al
  inc di
  loop hplot
  ret
pad: times 446 - ($-$$) db 0
ptable: times 64 db 0xff
sig: db 0x55, 0xaa
vga: equ 0xfa00
ioarr: equ 0x01
black: equ 0x00
red: equ 0x04
white: equ 0x0f
rad: equ 12
cloc: equ 0