Re: Videx Videoterm 80

[mressl@macgui.com (Marc S Ressl)]

Just a small addendum: it turns out the RC circuit only avoids video snow
and is not involved in removing spurious video output while scrolling.

The scrolling is actually handled elegantly by the MC6845 (I was emulating
it incorrectly). The MC6845's start address is only used when initializing
the current video address counter at the beginning of a frame. Changing it
in-frame does not change the current address counter, so scrolling is always
graceful. I thought I'd share this, in case somebody is interested in
understanding this.

With the best wishes,

Marc.-

Marc S Ressl wrote:
> Following the format of the previous posts, I'll continue describing old
> Apple II peripherals. And as before, this will soon be available in
> OpenEmulator :-).
>