That's the VDC :-) The designer brightly explained
to Bil Herd that you didn't
need the chip to send an IRQ when the screen was done drawing because you
could just poll it over and over. Even my computer-illiterate mother laughed
her head off when I told her about the Commodore engineers in the bar and
"ringer-less telephones" (just pick it up over and over and over ...).
Exactly. I'd spaced out on some of those details.
::This and more is detailed on Dave Haynie's
Deathbed Vigil video tape. A
::must-see.
Anywhere I can get it from? Dave was indispensible for the 7501/Plus4 sections
of Secret Weapons of Commodore.
I bought my copy from Dale Larson. I'm pretty sure it's an out of stock item.
-ethan