( my default test file )

:dev/r fff8 ( std read port )
:dev/w fff9 ( std write port )

;x 2 ;y 2 ;color 1 ;alive 1

|0100 @RESET 
	
	,01 ,dev/w STR ( set dev/write to screen ) 
	,01 ,color STR ( set color ) 	
	,0020 ,x STR2 ( set x-pos )
	,0030 ,y STR2 ( set y-pos )
	,01 ,alive STR ( set alive = true )

BRK

|c000 @FRAME 

	,alive LDR ,00 EQU BRK?
	,01 ,color LDR ,x LDR2 ,y LDR2 ,putpixel JSR
	,move JSR

BRK

@move
	,x LDR2 ,0001 ADD2 ,x STR2 ( incr x )
	,x LDR2 ,0040 LTH2 RTS?    ( if x > 60 )
	,0020 ,x STR2              ( x = 0x0020 )
	,y LDR2 ,0001 ADD2 ,y STR2 ( incr y )

	,y LDR2 ,0050 LTH2 RTS?    ( y > 50 )
	,00 ,alive STR             ( alive = 0 )

	RTS

@putpixel 
	IOW2 ( y short )
	IOW2 ( x short )
	IOW  ( color byte )
	IOW  ( redraw byte )
	RTS

|d000 @ERROR BRK 
|FFFA .RESET .FRAME .ERROR