These books all live and die on the notion that you can use a CPU to
generate the video timing more cheaply than you can build equivalent logic.
That was true in the '70's (when the TV-Typewriter Cookbook came out and it
is just as true now. I once had 'em but haven't seen 'em in years, probably
because I loaned 'em out.
Have you tried the local library?
I'd suggest you contemplate what this boils down to and save the expense and
effort of reading and/or duplicating Lancaster's work. It's valid, but it's
really much ado about nothing. It wasn't in the late '70's, however, since
digital video generation was much less widely understood back then, which is
why his books were such a popular item.
One beauty of the 6502 is that it can be set up with a symetrical Phase-0
clock, which results in a symetrical phase-1 and phase-2 clock, which, in
turn, supports sharing the static memory commonly used in shared memory
systems between two processors. You simply feed one CPU the complement of
the other's phase-0 clock and stand back. If one processor does the job of
managing the communication between the keyboard and system and the other
manges the video sync timing and the like, they never step on one another,
though they can communicate with one another and share the same memory.
If you want fast drawing, you simply map the video space into a small region
for each of several processors on the same clock phase, with that same space
shared with the one other processor who passes them parameters on the basis
of which they do their work. The shared memory is contiguously mapped for
the processor maintaining/refreshing the display, while it's in precisely
the same place for the guys doing the drawing. As a result the video guy
simply passes endpoints to each of the line/curve drawing processors, while
each of them runs the same code in the course of drawing. The video guy
decides who draws what and translates the specifications into segments for
each drawing slave, then passes the appropriate parameters.
Dick
----- Original Message -----
From: "Jeff Hellige" <jhellige_at_earthlink.net>
To: <classiccmp_at_classiccmp.org>
Sent: Monday, December 31, 2001 5:58 PM
Subject: Re: Cheap Video cookbooks and machines WTD
> >Philip Pemberton wrote:
> >
> >>Hi,
> >> I'm trying to get a copy of Don Lancaster's "Cheap Video Cookbook"
and
> >>"Son of Cheap Video" books, which are now out of print. Anyone got a
copy of
> >>both books they'd care to scan in and upload somewhere or sell to me?
What
> >>about the "TV Typewriter" article?
> >
> >
> > www.bookfinder.com located several copies of both books at various
prices
>
> I've also had good luck with www.abebooks.com when it comes
> to finding out of print stuff.
>
> Jeff
> --
> Home of the TRS-80 Model 2000 FAQ File
> http://www.cchaven.com
> http://www.geocities.com/siliconvalley/lakes/6757
>
>
Received on Mon Dec 31 2001 - 14:17:23 GMT