TITLE	"mp4demo.a -- demo of screen object model"

; demo program to output a centered X on the screen
; using the object-oriented screen interface

	USE	"hawk.macs"
	USE	"monitor.h"
	USE	"display.h"
	USE	"screen.h"

        COMMON  STACK,#1000
PSTACK: W       STACK

        S       MAIN
MAIN:
        LOAD    R2,PSTACK

        LOAD	R1,PSCRINIT
        JSRS    R1,R1
	MOVE	R8,R3		; R8 = screen = scrinit();

        LOADS   R1,R3
        LOAD    R1,R1,SIZE
        JSRS    R1,R1		; R3,R4 = height,width = screen.size()

	MOVE    R5,R4
        SR      R5,1		; p1 = width/2
        MOVE    R4,R3
        SR      R4,1		; p2 = height/2
	MOVE    R3,R8
        LOADS   R1,R3
        LOAD    R1,R1,AT
        JSRS    R1,R1		; screen.putat(p1, p2)

	MOVE	R3,R8
	LIS	R4,"X"
	LOADS	R1,R3
	LOAD	R1,R1,PUTC	
	JSRS	R1,R1           ; screen.putc("X")

	LOAD	R1,PEXIT	
	JSRS	R1,R1		; exit()

        END