-----Original Message-----
From: cctalk-bounces at
classiccmp.org [mailto:cctalk-bounces at
classiccmp.org]
On Behalf Of allison
Sent: Sunday, August 12, 2012 8:48 AM
To: General Discussion: On-Topic Posts Only
Subject: Re: X Window server for NEC 7220
[snip]
As one
of the product team for NEC at the time that's correct.
One has to remember the introduction of the part in 1981 predates the IBM
PC. The world at the time was 8bit busses (z80 common, 6502, or 8088
emerging). It had the needed bits for a dynamic ram interface for large
arrays
[snip]
Thanks Allison! The NEC uPD7220 is a historical GDC and never got the
appreciation it deserved for its ground breaking nature. It is a shame it
was overwhelmed by the domination of IBM PC and its use of the much
inferior, IMO, use of the MC6845 CRTC.
The MC6845/SY6545 works fine as a character mode CRTC for terminals and such
but it seems clear it was never really intended for bitmap graphics and we
have struggled with its strangeness ever since. Ironically many of the same
concepts found in the uPD7220 we later reintroduced to microcomputers as VGA
"accelerators" about 5-10 years later.
Regardless of whether the uPD7220 is suitable for bitmap graphics like an X
server, I am preparing an S-100 uPD7220 prototype board. If anyone would
like to participate in a build and test, getting prototype boards, or
whatever please contact me. It will be an S-100 version of the previously
developed N8VEM ECB uPD7220 board. Thanks and have a nice day!
Andrew Lynch
PS, BTW there are still plenty of the ECB uPD7220 GDC board PCBs left. They
are readily adapted to almost any microcomputer/embedded/vintage type
system. They work well and interface to standard VGA monitors.
