( my default test file )

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

;i ;x0 ;x1 ;y0 ;y1

|0100 @RESET 
	
	,01 ,dev/w STR ( set dev/write screen#01 ) 

BRK

|c000 @FRAME 
	
	,i LDR ,01 ADD ,i STR ( incr i )

	,i LDR ,x1 STR ( set x )

	,01 ,02 ,x0 LDR^ ,y0 LDR^ ,putpixel JSR

BRK

@onrow
	,y1 LDR ,01 ADD ,y1 STR
	RTS

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

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