.model small
.stack 256h
video equ 0b800h

.data
save_di dw ?
incr dw 1
.code
.386
start proc near
	mov ax, @data
	mov ds, ax
	mov ax, video
	mov es, ax
	mov ax, 4
	int 10h         ;sets at medium resolution
        mov ah, 0ch
	int 21h
	
	xor si, si
	xor dx, dx

call paint_back

mov di, 4    ;to begin the figure at the first even line

redraw:	
mov save_di,di
mov al,055h

call drawball
	
mov ah,1
int 21h
cmp al,'x'
je dosRet


mov al,0aah
;call drawball
call paint_back
mov di,save_di

;inc di
add di,incr

cmp di,10
jle cont
cmp di,4
jge cont
neg incr

	;;;input
cont:	
;mov dl, 0ffh
	
	;mov ah,6
	
	;int 21h
	;jnz dosRet
	jmp redraw
	
	done:
	mov ah,1
	int 21h
	dosRet:
	
		mov ax, 2
		int 10h
		mov ax, 4c00h
		int 21h
	
	start endp
pause proc
push cx
mov cx,32000
pusha
popa
pop cx
ret
pause endp
paint_back proc
	
	
	xor di, di     ;start di at first even line
	mov cx,1f40h   
	mov al, 0aah
	rep stosb
	mov di, 2000h
	mov cx,1f40h
	rep stosb
	
ret
paint_back endp

	drawball proc

	mov di,save_di          ;restore the starting position
	        
	mov cx, 1
	rep stosb       ;second even line
	add di, 78
	mov cx, 3
	rep stosb
	add di, 76   ;third even line
	mov cx, 5
	rep stosb
	add di, 76
	mov cx, 3
	rep stosb
	add di, 78
	mov cx, 1
	rep stosb

	mov di,save_di
	add di, 2000h  ;first odd line
	mov cx, 1
	rep stosb
	add di, 78 ;second odd line
	mov cx, 3
	rep stosb
	add di, 76   ;third odd line
	mov cx, 5
	rep stosb
	add di, 76
	mov cx, 3
	rep stosb
	add di, 78
	mov cx, 1
	rep stosb
	ret
	drawball endp
end start