The MOS 6567/6569 video controller (VIC-II) and its application in the Commodore 64 |
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Contents 3. Description of the VIC |
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The DEN bit (Display Enable, register $d011, bit 4) serves for switching on and off the text/bitmap graphics. It is normally set. The bit affects two functions of the VIC: The Bad Lines and the vertical border unit.
So clearing the DEN bit will normally prevent Bad Lines (and thus c- and g-accesses) from occuring and make the whole screen display the border color. |
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