I have a "PBXGK-BB" graphics card in an XP1000 box and would like to add a second one. It's a 16MB "PBXGB-CA" card I just took from another Alphastation. Both have VGA connectors.

However, the manual for the later states "In a multihead system, only one graphics module can have VGA enabled." There is a jumper for that.

How does one define a multihead system on OpenVMS, and what are the limitations? I'm confused. Should I even try?

Thanks in advance.
Slo

On 2021-09-16 19:33:08 +0000, Slo said:

> I have a "PBXGK-BB" graphics card in an XP1000 box and would like to
> add a second one. It's a 16MB "PBXGB-CA" card I just took from another
> Alphastation. Both have VGA connectors.
>
> However, the manual for the later states "In a multihead system, only
> one graphics module can have VGA enabled." There is a jumper for that.
>
> How does one define a multihead system on OpenVMS, and what are the
> limitations? I'm confused. Should I even try?

This isn't about the VGA connector.

This is the VGA graphics interface that is presented by the graphics
controller to the host computer.

When you have more than one graphics controller present, only one of
the controllers can have its VGA enabled.

Otherwise, the Alpha graphics console will get tangled.

Once DECwindows is operating, the higher-resolution graphics interfaces
are selected, and the VGA graphics interface isn't used until and
unless the console gets involved again.

All of that resolution-switching can happen over the VGA connector, or
via DVI for newer controllers.

I've routinely run multi-headed configurations and it works fine with
OpenVMS and DECwindows, though that's always been with consistent
controllers (multiple PowerStorm 3D30 controllers, for instance) and
with only one controller having VGA enabled, and that always using
DECwindows Motif as I never got DECwindows CDE multi-head working to my
satisfaction.

These days, aiming the graphics elsewhere via remote X, or using
multiple terminal sessions from a graphics-capable client system, can
be popular alternatives to multi-head configurations.

Though using three or four 21" CRTs can provide for a very nice and even tan.

Might have to play with the camera position and the CRT positions to
avoid a washed-out or flat look while video conferencing, though.

--
Pure Personal Opinion | HoffmanLabs LLC

> I have a "PBXGK-BB" graphics card in an XP1000 box [...]

Running some version or other of VMS?

> [...] only one graphics module can have VGA enabled." There is a
> jumper for that.

I can't see your "the manual", so I know nothing, including whether
that statement applies to VMS, but it might refer to one VGA _console_,
not a more general limitation on 15-pin D connectors.

> How does one define a multihead system on OpenVMS, and what are the
> limitations? [...]

RTFM? There should be loads of old DECwindows documentation lying
around. Look at SYS$MANAGER:DECW$PRIVATE_SERVER_SETUP.COM/.TEMPLATE? I
quote:

$ ! The simplest thing that can be done at this point, and the reason for
$ ! this call is to select multi-head. This is done by setting the symbol
$ ! DECW$MULTI_HEAD to logical True. And this is what the example does.

> [...] I'm confused. Should I even try?

I can think of one reliable way to find out.

I wouldn't bet on support for different cards, but what do I know?

Thanks for the prompt and helpful reply!
> Though using three or four 21" CRTs can provide for a very nice and even tan.
> Might have to play with the camera position and the CRT positions to
> avoid a washed-out or flat look while video conferencing, though.
:-)

No way I'll be using CRTs, the XP1000 is already using a 24" LCD, and I have a
pile of those around, as people move to laptops and throw/give them away.

> I've routinely run multi-headed configurations and it works fine with
> OpenVMS and DECwindows, though that's always been with consistent
> controllers (multiple PowerStorm 3D30 controllers, for instance) and
> with only one controller having VGA enabled, and that always using
> DECwindows Motif as I never got DECwindows CDE multi-head working to my
> satisfaction.

I'm on OpenVMS 8.4, New Desktop. Since this is based on DECwindows CDE,
I should be expecting difficulties?

I'll put in the second card and see what happens!

> I can't see your "the manual", so I know nothing, including whether
> that statement applies to VMS, but it might refer to one VGA _console_,
> not a more general limitation on 15-pin D connectors.

It's called "PBXGB-AA/CA PCI Graphics Option Owner's Guide"
Order Number: EK-PCIGR-OG. A01.
There is no mention of "console" anywhere in the docs, so VGA may
be referring to it.

> I can think of one reliable way to find out.
> I wouldn't bet on support for different cards, but what do I know?

I'll keep you posted, thanks! I'm on OpenVMS 8.4.

On 2021-09-16 21:43:42 +0000, Slo said:

>> I've routinely run multi-headed configurations and it works fine with
>> OpenVMS and DECwindows, though that's always been with consistent
>> controllers (multiple PowerStorm 3D30 controllers, for instance) and
>> with only one controller having VGA enabled, and that always using
>> DECwindows Motif as I never got DECwindows CDE multi-head working to my
>> satisfaction.
>
> I'm on OpenVMS 8.4, New Desktop. Since this is based on DECwindows CDE,
> I should be expecting difficulties?

A DECwindows configuration which offers CDE and Motif.

DECwindows can be reconfigured to default to Motif and not CDE.

> I'll put in the second card and see what happens!

Only one of which can have the VGA console enabled.

I've only run consistent graphics controller configurations, not disparate.

--
Pure Personal Opinion | HoffmanLabs LLC

> > I'll put in the second card and see what happens!
> Only one of which can have the VGA console enabled.
I won't touch the current card; on the new one, I'll disable VGA.
Hopefully, things will be ok on >>> and the OS, Motif.
Then, I'll attack multihead...

On 9/16/2021 5:43 PM, Slo wrote:

> No way I'll be using CRTs, the XP1000 is already using a 24" LCD, and I have a
> pile of those around, as people move to laptops and throw/give them away.

What? Laptops now have 24 inch displays? Or people are settling for less?

Dave doesn't have a laptop ...

Dave does have large LCD displays ...

--
David Froble Tel: 724-529-0450
Dave Froble Enterprises, Inc. E-Mail: davef@tsoft-inc.com
DFE Ultralights, Inc.
170 Grimplin Road
Vanderbilt, PA 15486

> What? Laptops now have 24 inch displays? Or people are settling for less?
Where a I live, people are leaving decent, dusty Windows desktop systems
on the street, or selling them for next to nothing. Years ago, it was old TVs
polluting the streets.

On Saturday, September 18, 2021 at 1:32:30 AM UTC+12, Slo wrote:
> Where a I live, people are leaving decent, dusty Windows desktop systems
> on the street, or selling them for next to nothing.

That’s Windows filesystem fragmentation for you. Not many people know how to reformat the hard drive and reinstall Windows to get it working like new again.

Or you could put a Linux system on it, and fix the slowdown problem once and for all.