Untitled

.model small
.stack
.code

mov eax,0B800h 	; segment of video buffer
mov es,ax 	; put this into es
xor di,di 	; clear di, ES:DI points to video memory
mov ah,4 	; attribute - red
mov al,"G" 	; character to put there
mov cx,4000 	; amount of times to put it there 
cld 		; direction - forwards
rep stosw 	; output character at ES:[DI]

mov ax,4C00h 	; return to DOS
int 21h

end