VSYNC in 9 bytes

Subject: VSYNC in 9 bytes
From: "Edwin Blink" <edwin.blink@xxxxxxx>
Date: Fri, 3 Sep 2004 00:59:54 +0200
I've been bytebusting a lot in keeping my menu I'm doing as(mall)ap and
just had one of those bright moments. Just needed to share this with you

;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
    BNE    VSLP1    ;branch until VYSNC has been reset

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