;A program to blank the screen, until a key is pressed.
;€ 1989  John Filsak
;This program was written for the Maxam II assembler.
;Other assemblers may require some things to be written a bit differently.

	org &100

;opening messages
	ld de,mess1
	call pr
	ld de,mess2
	call pr
	ld de,mess3
	call pr

	call keyp

;blank screen
	ld de,op1
	call pr

	call keyp

;restore screen messages
	ld de,op2
	call pr

	ret

;SUBROUTINES
;wait for keypress
keyp	ld c,6
	ld e,&fd
	call 5
	ret

;print to screen
pr	ld c,9
	call 5
	ret

op1	defb 27,'E$'
op2	defb 27,'H',27,'e',27,'1$'
mess1	defb 27,'E',27,'0',27,'f',27,'HBLANK   €1989   by John Filsak',10,10,13,'$'
mess2	defb 'Press a key to blank the screen entirely.',10,10,13,'$'
mess3	defb 'A further keypress will restore the screen ',10,13,'and return you to CP/M.$'
                                      