VCCC 2023 x86 assembly

README.md

My non-optimized past-deadline attempt for VCCC 2023

• Author: Lea Rosema
• Platform: MS-DOS
• Length Source: 568 bytes
• Length Code: 83 bytes

Instructions

• Turn on your vintage computer running DOS or use DOSBox
• Download NASM for DOS
• Compile via nasm.exe pattern.asm -fbin -o pattern.com
• run pattern.com

PATTERN.ASM

	org	100h

LINES	equ	25
COLS	equ	40

section .text

entry:	mov	ax,0x01
	int	0x10
	mov	di, 0xb800
	mov	es, di
	xor	di,di
	mov	ax, 0x1e20
	mov	cx, LINES * COLS
	rep	stosw
	xor	di, di
	mov	dx,18
loopy:	mov	cx,18
loopx:	mov	ax,cx
	mul	al
	mov	bx,ax
	mov	ax,dx
	mul	al
	add	bx,3
	sub	bx,ax
	mov	ax,bx
	mov	bx,6
	idiv	bl
	cmp	ah,0
	jnz	skip
	mov	byte es:[di],'*'	
skip:	add	di,2
	dec	cx
	jns	loopx
	add	di,(COLS-19)*2 ; new line 
	dec	dx
	jns	loopy
	mov	ax,0
	int	0x16
	mov	ax,3
	int	0x10
	int	0x20

section .data

section .bss