; Mikolaj Felix 9/12/2000
; mfelix@polbox.com

copy_screen_buffer proc
	push ds
	push es
	mov ax,buffer_seg
	mov ds,ax
	xor si,si
	mov ax,0a000h
	mov es,ax
	xor di,di
	mov cx,16000
	cld
	rep movsd
	pop es
	pop ds
	ret
endp

clear_screen_buffer proc
	push es
	mov ax,buffer_seg
	mov es,ax
	xor di,di
	xor eax,eax
	mov cx,16000
	cld
	rep stosd
	pop es
	ret
endp

alloc_screen_buffer proc
	mov ah,4ah
        mov bx,1000h
        int 21h
        mov ah,48h
        mov bx,1000h
        int 21h
        jc asb_out_of_mem
	mov buffer_seg,ax
	ret
asb_out_of_mem:
	mov ah,09h
        mov dx,offset oom_string
        int 21h
	mov ah,4ch
	int 21h
	ret
endp

free_screen_buffer proc
	push es
	mov ax,buffer_seg
        mov es,ax
        mov ah,49h
        int 21h
	pop es
	ret
endp

wait_for_frame proc
	mov dx,03dah
c1:
	in al,dx
	test al,8
	jz c1
c2:
	in al,dx
	test al,8
	jnz c2
	ret
endp

oom_string db 'Out of memory!',10,13,'$'
buffer_seg dw ?