9 Mar
2008
9 Mar
'08
2:25 p.m.
Date: Sat, 08 Mar 2008 16:50:10 -0800
From: davis
An apocryphal story I heard was that the graphics on
the display are
disk/?drum refreshed. If true, I assume you would need the better part of
a CDC 6x00 to get anything out of it.
Aprocryphal, indeed--and completely without basis in reality. The
6602/6612 display was directly driven by a single 4Kword PPU with no
automatic refresh. If you generated a complex display, it tended to
flicker, as the PPU couldn't refresh in time. This also explains why
the graphics mode wasn't used more--it simply took too much time to
generate anything other than a simple display.
I speak as a writer of a DSD overlay or two.
Cheers,
Chuck