10 Aug
2012
10 Aug
'12
1:09 p.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Al Kossow
Sent: Friday, August 10, 2012 3:24 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: X Window server for NEC 7220
On 8/10/12 10:53 AM, Andrew Lynch wrote:
video
If you or anyone else has some insight on how to
implement a register
compatible SVGA on the S-100 bus I am very willing to listen! Thanks
and have a nice day!
I guess I'm not clear on what your requirements are for this S-100 video
display.
Rather than working backwards from the chips that are available, what do
you want to DO with it? resolution, bit depth, frame rate, frame buffer
organization (planar or chunky pixels). I assume the target is a common output format like RGB VGA.
Hi! The goal for the S-100 VGA board is to make a register compatible SVGA
that uses commonly available VGA monitors. The application would be an X
server for the upcoming S-100 80386 CPU board. Also to provide a greater
degree of PC/XT/AT compatibility for the S-100 80286, S-100 8086, and S-100
8088 CPU boards. Presumably, an S-100 SVGA board would also be usable by
non-Intel x86 CPU boards as well but that is optional. If VGA is not viable
then we need to explore other options to provide a bitmap display for the X
server.
The primary goal of the S-100 80386 CPU board project is to run a "modern
sophisticated" operating system such as Linux and/or NetBSD. Both require a
32 bit ISA, an MMU, and a whole lot of RAM. Yes, you can run both without
an X server but sooner or later you'll almost certainly want some sort of
graphical interface because much current software assumes a GUI.
Potentially any solution for the S-100 80386 could potentially be applied to
the MC68040 SBC also currently in development.
The technical specifications, such as they exist, are quite modest. IBM VGA
register compatibility with 16 color, 800x600, 60 Hz refresh rate, and no
preference for frame buffer. The closer to compatible with the stock IBM
VGA the better. It does have to be "buildable" by hobbyists though so
certain technologies are undesirable (SMT and programmable logic) or
unacceptable (BGA). There is no preference for any particular chipset
however it cannot rely on an undocumented BIOS which has proven to be the
fatal flaw with the CLGD542x chipset (**please** someone prove me wrong and
post a commented CL GD542x BIOS listing!)
S-100 80386
http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder¶m=S-100%2080…
0CPU%20board
S-100 SVGA
http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder¶m=S-100%20VGA
Further complicating matters is that all the "open source VGA" projects I am
aware of have fizzled as well. This is a non-trivial problem and may not be
solvable with a VGA chipset. Thus the interest in NEC uPD7220 as an
alternative.
http://hackaday.com/2012/06/05/open-source-graphics-card/
http://wacco.mveas.com/
http://wiki.opengraphics.org/tiki-index.php
Thanks and have a nice day!
Andrew Lynch