Video "ringing" with PBXGA but not Mach64 or Elsa Gloria
Alan Frisbie
AlphaStation 200, and have a couple of questions.
It came with a PBXGA-BA/BN (ZLXp-E2) video card. If I
used an absolutely top-quality (e.g. expensive) video
cable, I got an acceptable 1280x1024 display on my ViewSonic
PS790 monitor, going through the BNC connectors.
If, however, I used a lesser-quality cable or tried to
route it through my Raritan MX48 KVM switch, I saw lots
of video "ringing". That is, every vertical line had
"echos" or "ghosts" to the right of it. I did not see
this on any of my other systems.
Since I did not see this problem on another Alpha with an
ATI video card, I tried switching to an ATI Mach64 video
card and the problem went away completely! Just to
complete the test, I also tried an Elsa Gloria Synergy II
card and it also worked perfectly. No ringing, even
with a cheap cable or going through the KVM switch.
What is it about the PBXGA/ZLXp-E2 card that causes this
ringing, that is not present with the other two cards?
On a related note, what video cards will work in the
AlphaStation 200? I have heard that some of the later
ones will not work with the EV4 CPUs. A matrix showing
cards, systems, and relative performance would be wonderful.
Does such a thing exist?
Thanks,
Alan Remove "REMOVE" from address to reply
Hoff Hoffman
:On a related note, what video cards will work in the
:AlphaStation 200? I have heard that some of the later
:ones will not work with the EV4 CPUs. A matrix showing
:cards, systems, and relative performance would be wonderful.
:Does such a thing exist?
The PBXGB-AA PowerStorm 3D30 (TGA2) is probably the nicest controller
with formal support, IIRC. Even if the PowerStorm 3D30 is supported,
it is probably overkill for this AlphaStation 200 series box.
For hardware support details:
http://h18002.www1.hp.com/alphaserver/
http://h18002.www1.hp.com/alphaserver/workstations/retired/index.html
The AlphaStation 200 box is sufficiently old and slow that I'm not at
all certain the graphics board would be my first target for an upgrade.
Y'all are simply not going to get performance from an ancient EV4-based
system, no matter the graphics controller chosen.
The 3DLabs Oxygen VX1 device drivers will not function with an EV4-class
Alpha microprocessor, such as that found on your AlphaStation 200.
The PowerStorm 3D10T ELSA GLoria Synergy is probably the newest card
that has a shot of working, though I do not know if that would be
supported in this configuration.
Various of the older AlphaStation systems either lacked the byte-word
instructions (systems prior to EV56) or the platform-specific PCI bus
I/O addressing that can be required by more recent device drivers;
adding support for newer graphics onto older systems is not something
that is normally expected.
Have you tried other resolutions with the TGA (ZLXp-E2) card, on the off
chance the problem is a disagreement between the monitor and the graphics
controller and (when present) the KVM? The switch settings for the
ZLXp-E* series controllers are posted at Ask The Wizard topic (6965).
This would certainly not be the first time that a controller, a KVM and
a monitor had signal integrity problems. Try a less aggressive setting
as a test, obviously.
The OpenVMS FAQ has an introduction to matching up video display and
controller settings, as well.
---------------------------- #include <rtfaq.h> -----------------------------
For additional, please see the OpenVMS FAQ -- www.hp.com/go/openvms/faq
--------------------------- pure personal opinion ---------------------------
Hoff (Stephen) Hoffman OpenVMS Engineering hoff[at]hp.com
Alan Frisbie
> The AlphaStation 200 box is sufficiently old and slow that I'm not at
> all certain the graphics board would be my first target for an upgrade.
> Y'all are simply not going to get performance from an ancient EV4-based
> system, no matter the graphics controller chosen.
I agree. I simply wanted to get rid of the blasted "ringing".
Since I had the other cards on hand, I tried them.
I would like to upgrade to a higher-performance system like a
DS10 or XP1000, but David Turner keeps buying them up and keeping
the price high. :-) (Just kidding, David)
And yes, I will buy the HP version of the video card for whatever
new system I get. I want to keep those VMS engineers employed.
> The 3DLabs Oxygen VX1 device drivers will not function with an EV4-class
> Alpha microprocessor, such as that found on your AlphaStation 200.
As I suspected. Thanks for the confirmation.
> The PowerStorm 3D10T ELSA GLoria Synergy is probably the newest card
> that has a shot of working, though I do not know if that would be
> supported in this configuration.
Supported or not, it has been working nicely all afternoon and
I am very happy with it. If it fails to work at some point, I
will just fall back to the ATI Mach64 card.
I did determine that the ATI Rage XL will *NOT* work, at least in
my configuration.
> Have you tried other resolutions with the TGA (ZLXp-E2) card, on the off
> chance the problem is a disagreement between the monitor and the graphics
> controller and (when present) the KVM? The switch settings for the
> ZLXp-E* series controllers are posted at Ask The Wizard topic (6965).
> This would certainly not be the first time that a controller, a KVM and
> a monitor had signal integrity problems. Try a less aggressive setting
> as a test, obviously.
Thank you for an excellent suggestion. I was running it at
switch setting 13, which is the most agressive 1280x1024 setting:
135 MHz pixel clock, 75 Hz vertical rate. The next time I have
a reason to power-down I will put it back in and try the other settings.
This might explain why one user e-mailed me to say that he was not
having any ringing problems with long, cheap cables.
Thanks for the excellent information. I'm looking forward to
seeing you again at the VMS symposium next month.
Alan Remove "REMOVE" to reply
Hoff Hoffman
..
:I would like to upgrade to a higher-performance system like a
:DS10 or XP1000...
As OpenVMS I64 releases continue to roll out, remember that another
hardware upgrade option that is becoming more readily available to
OpenVMS users includes new or used members of the HP Integrity series
systems. (Look at the web prices for various of the Integrity boxes,
for example.)
:> The PowerStorm 3D10T ELSA GLoria Synergy is probably the newest card
:> that has a shot of working, though I do not know if that would be
:> supported in this configuration.
:
:Supported or not, it has been working nicely all afternoon and
:I am very happy with it.
The PowerStorm 3D10T is a comparatively slow controller. (Which
might well suit your AlphaStation 200 box, but I digress. :-) On
various of the faster AlphaStation series systems, the relatively
limited performance of the PowerStorm 3D10T can be disconcerting.
The PowerStorm 3D30 (and PowerStorm 4D20) offer *very* fast 2D,
and I would almost always choose a PowerStorm 3D30 controller
over a PowerStorm 3D10T -- and I'd probably also choose it over
many other 2D graphics controllers, for that matter.
..
:I did determine that the ATI Rage XL will *NOT* work, at least in
:my configuration.
The drivers for the ATI Radeon 7500 graphics controller are not
expected to operate within this AlphaStation 200 series or other
similar-vintage configurations. The microprocessor is too far
back, and the I/O bus interface requires byte-swizzling.
The cut-off for new graphic controller support is generally EV6
and later, though a few and very specific EV56 boxes might also
be supported. The key here is byte-word addressing within the
Alpha microprocessor and a non-swizzled I/O space bus interface.
(If your driver's call into IOC$NODE_FUNCTION returns a zero for
the swizzle shift count, you're good to go. If the call returns
non-zero, you can make calls to IOC$READ_IO and IOC$WRITE_IO --
which handle swizzled and non-swizzled references for you -- or
you are soon to learn about swizzling... Various of the graphics
device drivers have substantial knowledge of I/O space and of the
processor and can and do go directly at the I/O device.) Whoops,
that's probably _way_ more detail than you cared to know about...
Alan Frisbie
> The cut-off for new graphic controller support is generally EV6
> and later, though a few and very specific EV56 boxes might also
> be supported. The key here is byte-word addressing within the
> Alpha microprocessor and a non-swizzled I/O space bus interface.
> (If your driver's call into IOC$NODE_FUNCTION returns a zero for
> the swizzle shift count, you're good to go. If the call returns
> non-zero, you can make calls to IOC$READ_IO and IOC$WRITE_IO --
> which handle swizzled and non-swizzled references for you -- or
> you are soon to learn about swizzling... Various of the graphics
> device drivers have substantial knowledge of I/O space and of the
> processor and can and do go directly at the I/O device.) Whoops,
> that's probably _way_ more detail than you cared to know about...
Perhaps at the moment, but I'll save if for future reference.
Paul Repacholi
> Since I did not see this problem on another Alpha with an ATI video
> card, I tried switching to an ATI Mach64 video card and the problem
> went away completely! Just to complete the test, I also tried an
> Elsa Gloria Synergy II card and it also worked perfectly. No
> ringing, even with a cheap cable or going through the KVM switch.
> What is it about the PBXGA/ZLXp-E2 card that causes this ringing,
> that is not present with the other two cards?
Very fast edges on the video signals, ie, higher bandwidth video output.
The higher frequencies are more sensitive to impedance mismatches from
the cables or the DC15 connector. USe a card that cant generate as high
frequencies in the video, and ot will not be as dificult to keep the
edges clean.
--
Paul Repacholi 1 Crescent Rd.,
+61 (08) 9257-1001 Kalamunda.
West Australia 6076
comp.os.vms,- The Older, Grumpier Slashdot
Raw, Cooked or Well-done, it's all half baked.
EPIC, The Architecture of the future, always has been, always will be.
Rich Jordan
>
>
>>Since I did not see this problem on another Alpha with an ATI video
>>card, I tried switching to an ATI Mach64 video card and the problem
>>went away completely! Just to complete the test, I also tried an
>>Elsa Gloria Synergy II card and it also worked perfectly. No
>>ringing, even with a cheap cable or going through the KVM switch.
>
>
>>What is it about the PBXGA/ZLXp-E2 card that causes this ringing,
>>that is not present with the other two cards?
>
came with a monitor cable that grounded one of the three color signal
grounds, or was used with a monitor that performed the same function.
If you scope the card, I believe two of the three color signal ground
wires (red and blue if I recall correctly) are grounded, while the third
(green?) ground is floating.
My AS200 is running and I can't take it apart right now, but it has an
-E2 card in it that I modified; I soldered a wire-wrap wire from the
floating (green?) signal ground to 'another' ground on the backside of
the card, where the HD15 connector was attached. I no longer have the
reference, and I really can't take the system down to check, sorry. But
that cleaned up the fringing and gave me a rock solid display on just
about any monitor I cared to try it with.
Rich Jordan
All disclaimers apply; if your system poofs its magic smoke, its not my
fault...
Alan Frisbie
Thanks for the note. My board is a Revision D04, and a quick ohmmeter
check shows that all three analog ground pins (6, 7, & 8) are all
connected to ground. Perhaps they caught this goof and fixed it.
I still haven't tried Hoff's suggestion (use a less "agressive"
scan rate), but I will this evening. In the meantime, the Elsa
board is working fine.
Thanks,
Alan
Alan Frisbie
>> Alan Frisbie <Usenet0...@Flying-Disk.com> writes:
>>> Since I did not see this problem on another Alpha with an ATI video
>>> card, I tried switching to an ATI Mach64 video card and the problem
>>> went away completely! Just to complete the test, I also tried an
>>> Elsa Gloria Synergy II card and it also worked perfectly. No
>>> ringing, even with a cheap cable or going through the KVM switch.
> The ZLXp-E2 card (maybe others in the series) reportedly originally
> came with a monitor cable that grounded one of the three color signal
> grounds, or was used with a monitor that performed the same function. If
> you scope the card, I believe two of the three color signal ground wires
> (red and blue if I recall correctly) are grounded, while the third
> (green?) ground is floating.
BINGO! That was it! Even though an ohmmeter showed zero resistance
between the three analog grounds (pins 6, 7, & 8), a small wire (I
used 30ga wire-wrap wire) soldered across all three pins cured the
problem. Now I can use the ZLXp-E2 at all 1280x1024 rates, including
the most "agressive", setting 13 (80 KHz Horiz, 75 Hz Vert).
I am now using it through my Raritan KVM switch and cables without a
trace of "ringing".
Hoff, do you suppose you could get this added to the FAQ or Wizard
answers in case anyone else hits this problem?
Thank you all for your helpful suggestions.
Now I have just one remaining question: Why does "Style Manager - Color"
not allow me to change colors (the "Modify" button is greyed out) with
the ZLXp-E2, but does allow it with the Elsa and ATI boards?
Alan
Alan Frisbie
> BINGO! That was it! Even though an ohmmeter showed zero resistance
> between the three analog grounds (pins 6, 7, & 8), a small wire (I
> used 30ga wire-wrap wire) soldered across all three pins cured the
> problem. Now I can use the ZLXp-E2 at all 1280x1024 rates, including
> the most "agressive", setting 13 (80 KHz Horiz, 75 Hz Vert).
Just to be complete, I should add that before adding the wire, I
tried Hoff's suggestion that I test other switch settings (i.e.
different scan rates) on the ZLXp-E2. No matter what the switch
setting, the video ringing still occured.
My guess is that the BNC connection to my monitor (which worked
perfectly) has all three grounds connected together. When I
used the HD-15 connector (directly, through cheaper cable, or
via the KVM switch), I'm guessing that they are not (or that
it somehow requires them to be connected at the video card).
The "floating" ground then resulted in the ringing I saw.
The reason the Elsa and ATI boards did not have the problem is
apparently because all three grounds are connected at the video
card. Now that I have made the fix to the ZLXp-E2, they all
have equally good images.
But, as I mentioned in my previous note, I still would like to
know why the DECwindows "Style Manager - Color" does not allow
me to change colors (the "Modify" button is greyed out) with
the ZLXp-E2, but does allow it with the Elsa and ATI boards?
Thanks,
Alan
Hoff Hoffman
:Hoff, do you suppose you could get this added to the FAQ or Wizard
:answers in case anyone else hits this problem?
Having done some more digging, the official answer is to always use the
PBXGA-BA/BN or PBXGA-CA/CN ZLXp-E* series graphics controller cards only
with a DIGITAL-supplied BC13L-10 or BC14J-10 series video signal cable.
What you are seeing -- the ghosting -- can be a known and expected problem
if a another cable is used. If you purchase one of these graphics cards,
you will want to ensure you receive the cable.
It would not surprise me that the cables manipulate the ground, but I
do not know that -- and I haven't dug through my stash of cables to see
if I have one of these available for some continuity testing. I'm also
not in a particular position to recommend a solution based on soldering,
but y'all probably guessed that already.
:Now I have just one remaining question: Why does "Style Manager - Color"
:not allow me to change colors (the "Modify" button is greyed out) with
:the ZLXp-E2, but does allow it with the Elsa and ATI boards?
Donno. Not enough planes?
Bob Koehler
> Alan Frisbie wrote:
>
>> BINGO! That was it! Even though an ohmmeter showed zero resistance
>> between the three analog grounds (pins 6, 7, & 8), a small wire (I
>> used 30ga wire-wrap wire) soldered across all three pins cured the
>> problem. Now I can use the ZLXp-E2 at all 1280x1024 rates, including
>> the most "agressive", setting 13 (80 KHz Horiz, 75 Hz Vert).
>
> Just to be complete, I should add that before adding the wire, I
> tried Hoff's suggestion that I test other switch settings (i.e.
> different scan rates) on the ZLXp-E2. No matter what the switch
> setting, the video ringing still occured.
Where the ground is located can be quite important at the data rates
your getting over that cable. I've seen lots of data cables ring
when common ground was over 3 feet away from the end of a cable.
Rich Jordan
> In article <3F9F2054...@Flying-Disk.com>, Alan Frisbie <Usenet0...@Flying-Disk.com> writes:
> :Hoff, do you suppose you could get this added to the FAQ or Wizard
> :answers in case anyone else hits this problem?
>
> Having done some more digging, the official answer is to always use the
> PBXGA-BA/BN or PBXGA-CA/CN ZLXp-E* series graphics controller cards only
> with a DIGITAL-supplied BC13L-10 or BC14J-10 series video signal cable.
> What you are seeing -- the ghosting -- can be a known and expected problem
> if a another cable is used. If you purchase one of these graphics cards,
> you will want to ensure you receive the cable.
>
Of course that presupposes you're using a monitor that doesn't have its
own hardwired video cable; not an issue with the genuine article DEC
parts, but lots of generic PC units like my Nokia are handicapped with a
fixed cable. The grounding modification lets them all work with the -E2
card. I would have used a VR299, which worked with VMS on that box, but
since I had to share usage with NT Alpha, and that braindead POS had no
way to turn on/leave on the sync-on-green function we had to get a
different monitor.
>
> :Now I have just one remaining question: Why does "Style Manager - Color"
> :not allow me to change colors (the "Modify" button is greyed out) with
> :the ZLXp-E2, but does allow it with the Elsa and ATI boards?
>
> Donno. Not enough planes?
>
>
-E2 is supposed to be a 24-plane card, if I remember correctly. My
books are still packed so I can't verify it.
Rich Jordan
Fred Kleinsorge
> :Now I have just one remaining question: Why does "Style Manager - Color"
> :not allow me to change colors (the "Modify" button is greyed out) with
> :the ZLXp-E2, but does allow it with the Elsa and ATI boards?
>
> Donno. Not enough planes?
>
By default with TrueColor, you cannot dynamically change the colors. But
there is a documented way to make it dynamic - it's in the CDE
documentation.