Re: [stella] VSYNC in 9 bytes

Subject: Re: [stella] VSYNC in 9 bytes
From: "Thomas Jentzsch" <tjentzsch@xxxxxx>
Date: Fri, 03 Sep 2004 12:28:48 +0200
Edwin Blink wrote::
> ;generates vertical sync pulse for 3 full scanlines.
> ;VBLANK should be set by the overscan code and is not set here
>     LDA    #$0E    ;each '1' bits generate a VSYNC ON line (bits 1..3)
> VSLP1    STA    WSYNC    ;1st '0' bit resets Vsync, 2nd '0' bit exit loop
>     STA    VSYNC
>     LSR
>     BNE    VSLP1    ;branch until VYSNC has been reset

Very nice indeed for maximum compact code. 

But it should be mentioned that it wastes one whole scanline, which 
sometimes might be very useful. So, who has an optimal solution
for that? 10 bytes maybe?

Have fun!
Thomas Jentzsch         | *** Every bit is sacred ! ***
tjentzsch at web dot de |
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