; Simple Grayscale demo created by Matthew Johnson 
;  Must include BlitzGry.h 
 
;  "86 Central" - Largest TI-86 Asm Programmin Research Site 
;  http://www.dogtech.com/cybop/ti86/ 
; E-mail me! matt2000@gte.net 
 
#include "ti86asm.inc" 
 
.org _asm_exec_ram 
		call 	_clrLCD 
        call    OpenGray 
 
; When a pixel is set at $FC00 and $CA00, it appears dark (black) 
; If the pixel is only set at $FC00 it appears dark grey 
; If the pixel is only set at $CA00 it appears light grey 
; If the pixel is clear at $FC00 and $CA00 then it appears light  
 
; First Quarter of Screen 
 
		ld      hl, $FC00 
		ld		(hl), $FF 
        ld      de, $FC01 
        ld      bc, 255 
        ldir 
 
		ld      hl, $CA00 
		ld		(hl), $FF 
        ld      de, $CA01 
        ld      bc, 255 
        ldir 
 
; Second Quarter of Scree 
 
		ld      hl, $CB00 
		ld		(hl), $00 
        ld      de, $CB01 
        ld      bc, 255 
        ldir 
 
		ld      hl, $FD00 
		ld		(hl), $FF 
        ld      de, $FD01 
        ld      bc, 255 
        ldir 
 
; Third Quarter of Screen 
 
		ld      hl, $CC00 
		ld		(hl), $FF 
        ld      de, $CC01 
        ld      bc, 255 
        ldir 
 
		ld      hl, $FE00 
		ld		(hl), $00 
        ld      de, $FE01 
        ld      bc, 255 
        ldir 
 
; Fourth Quarter of Screen 
 
		ld      hl, $CD00 
		ld		(hl), $00 
        ld      de, $CD01 
        ld      bc, 255 
        ldir 
 
		ld      hl, $FF00 
		ld		(hl), $00 
        ld      de, $FF01 
        ld      bc, 255 
        ldir 
 
getkey: 
        ld a,%00111111 
        out (1),a 
        nop 
        nop 
        in a,(1) 
        bit 6,a 
		jr nz, getkey 
 
		call CloseGray 
 
        call    _runindicon 
        ret 
 
#include "BlitzGry.h" 
.END