Subject: X Servers
To: None <>
From: Matt Thomas <>
List: port-vax
Date: 03/11/2002 08:39:33
Any Xserver support for the VAX must be added into the
existing Xdec Xserver code (which is for DECstations (pmax)
and AlphaStations (alpha)).  It already is wscons based
and knows about the LK201 and DEC VSXXX mice.  The sources
are located in xsrc/xc/programs/Xserver/hw/netbsd/dec.

That being said, there are 5 possible classes of Xservers
that could run on the VAX.  <dev/wsconsio.h> already has
the following defines for VAX framebuffer types:

#define         WSDISPLAY_TYPE_SPX      18      /* DEC SPX (VS3100/VS4000) */
#define         WSDISPLAY_TYPE_GPX      19      /* DEC GPX (uVAX/VS2K/VS3100 */
#define         WSDISPLAY_TYPE_LCG      20      /* DEC LCG (VS4000) */
#define         WSDISPLAY_TYPE_VAX_MONO 21      /* DEC VS2K/VS3100 mono */

The only one missing is the QVSS (mono Qbus framebuffer).
If someone actually has one, I suppose a WSDISPLAY type
could be added for it.  But I'd like to see code for it
first. :)  Note that all FBs need to have standard wscons
support written for them first so they can be used as

SPX is used on the VS31000 and VS4000.  It stands for
Scanline Processor and I know of no available documentation
for it other than the VMS source listings.

GPX is used on Q-bus MicroVAXes with the QDSS (GPX) and
the VS3100 (std color).  These use the Dragon chipset and
the QDSS documentation cover this is great detail.  The
X sources already have a QDSS driver but it needs to
completely written to fit into a wscons framework.  The
same is true for the dev/qbus/qd.c driver.  It must be
rewritten before being useful.

LCG (low cost graphics) is used on VS4000s and I do have
documentation for this board.  It should be simple to just
treat this as a dumb framebuffer initially and then add
support for treating as an intelligent framebuffer latter
on.  It has support for doing most X ops in hardware.

VAX_MONO should only take a few hours to get working in the
Xdec server since all that needs to be done it to teach it
about the VAX mono framebuffers.

Matt Thomas               Internet:
3am Software Foundry      WWW URL:
Cupertino, CA             Disclaimer: I avow all knowledge of this message