18 Jun
2009
18 Jun
'09
2:26 p.m.
remember the APC had the ability to pan on a larger virtual "scree". The native
resolution was 640 x 400/or 480. The virtual screen was like twice that (at least). That
might be the reason for the complexity.
I've seen much less dense boards based on the 7220.
JOOC, where are you getting these 7220s from?
--- On Wed, 6/17/09, Peter C. Wallace <pcw at mesanet.com> wrote:
From: Peter C. Wallace <pcw at mesanet.com>
Subject: RE:NEC uPD7220/GDC Design Manual
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Date: Wednesday, June 17, 2009, 9:45 PM
On Wed, 17 Jun 2009, Andrew Lynch
wrote:
Date: Wed, 17 Jun 2009 21:37:04 -0400
From: Andrew Lynch <lynchaj at yahoo.com>
Reply-To: "General Discussion: On-Topic and Off-Topic
Posts"
<cctalk at classiccmp.org>
To: cctalk at classiccmp.org
Subject: RE:NEC uPD7220/GDC Design Manual
--- On Wed, 6/10/09, Andrew Lynch wrote:
interested in selling it? I contacted NEC and
they didn't know anything
about it. Apparently very few people still have
the manual and bitsavers
doesn't have it either. I did some library
searches but no luck although it
is cited as a reference in a couple of college
papers
like masters thesis,
etc.
What I really need to know is if I can implement a
simple circuit using few
enough 74LS TTL ICs to fit on a Eurocard ECB
board. That means it can't be
more than about 30 maximum. Using high capacity
SRAMs should help but I
think it requires some funky latching mechanisms
to
share the video address
and data lines.
I looked at the NEC APC video board and it is just
huge. I hope that is not
an indication of the complexity needed!
Thanks and have a nice day!
Andrew Lynch
Probably 30 would do, I have in front of me a S100 card
with a 7220. 128KB of
64 Kb DRAM and 31 TTL ICs...
Peter Wallace
Mesa Electronics
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