10 Aug
2012
10 Aug
'12
9:59 a.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
On Behalf Of Richard
Sent: Friday, August 10, 2012 12:22 PM
To: cctalk
Subject: Re: X Window server for NEC 7220
In article <000c01cd76f7$f59bf1d0$e0d3d570$(a)YAHOO.COM>OM>,
"Andrew Lynch" <LYNCHAJ at yahoo.com> writes:
rather
the
Does anyone know of an X Window server
implementation for the NEC 7220
GDC?
<http://bitsavers.org/pdf/nec/uPD7220-uPD7220A_User_Manual_Dec85.pdf>
It's unlikely that there will be a server implementation for this chip; server implementation would be for a product that used
this chip. That
would typically mean a unix workstation using this chip.
So your first step would be to identify a unix workstation from this time
frame
that had a graphics board based on this chip and then
find an X server for
it.
If you really want to pursue porting the X server to this chip as a
project, then
get an older X11 distribution like X11R5 and use this
book:
X Window System Server: X Version 11, Release 5, by Elias Israel and Erik
Fortune Digital Press
<http://www.amazon.com/gp/product/0139727531/ref=as_li_ss_tl?ie=UTF8&c
amp=1789&creative=390957&creativeASIN=0139727531&linkCode=as2&tag=le
galiadulth-20>
I have this book and have read it. It is a very good treatment of how to
port
the X server to new hardware. If you pursue this, I
can help you, I have
done
X server work in the past.
It is much harder to port the current codebase because of the way they
have
fractured the distribution. I understand why they did
it (decreasing
resources
at X.org), but it is much, much harder to bring the
current X server code
base
to a new hardware platform than it was before. So far
I have been
unsuccessful in simply compiling it for an existing well supported ubuntu
distribution due to the disparate dependencies.
--
"The Direct3D Graphics Pipeline" free book
<http://tinyurl.com/d3d-pipeline>
The Computer Graphics Museum
<http://computergraphicsmuseum.org>
The Terminals Wiki <http://terminals.classiccmp.org>
Legalize Adulthood! (my blog) <http://legalizeadulthood.wordpress.com>
Hi Richard! Thanks! I will look into your recommended book.
I am not aware of any workstations that used the NEC 7220 GDC. There were
some Multibus implementations of the chip so I suppose it is possible they
exist. Many of the Intel 82720 and NEC uPD7220 boards were highly
specialized niche products so it is entirely possible they exist but are not
in common knowledge.
http://www.multibus-international.com/int-intel-corp/sbx275
On a similar vein, I am aware of X Window(s) server for the VESA API for VGA
boards. Most all VGA boards adhere to the VESA standard and provides quite
a bit of portability although performance is generally fairly low. Would it
be possible/feasible to create a VESA API for a NEC uPD7220A video board?
In other words, is the VESA API inherently VGA MC6845 centric or is it
hardware abstract enough to be ported to other video chips?
At the N8VEM home brew computing project we already have a NEC uPD7220A
board that works and has been debugged. However creating software for it
has proven to be problematic.
http://n8vem-sbc.pbworks.com/w/browse/#view=ViewFolder¶m=ECB%20uPD7…
0GDC
I am considering converting the above design to S-100 bus for a companion to
the upcoming S-100 68K CPU board (final board due out later this summer) and
the S-100 80386 CPU board (initial prototype boards just ordered).
The N8VEM ECB uPD7220A board is a pure 16 color bitmap design. There is no
explicit text character mode. The video memory is theoretically upgradeable
to 256 colors by adding another 4 color planes. Since it uses a BT478
RAMDAC and VGA compatible dot-clock frequencies it can use 640x480 and
800x600 displays on regular VGA monitors.
Thanks for your reply and comments. Thanks and have a nice day!
Andrew Lynch