IBM 6091 23" Monitor

[luciodandrea]

Hi! I have a problem that seems really dificult to solve (not impossible, since people hace done it)....
I have an IBM 6091 23" fixed frequency monitor, which I need to make it work with my desktop PC, which has an Intel 82845G video card...
I've downloaded Powerstrip, a little program that lets you configure every parameter of the video card...
I've been playing around with it for about two days, but the only thing I get on my screen is a poor image of my desktop...
I know that some other people had worked it out to make it work, (not necesarly using powerstrip, but it's a good choice), but I can't!
does anyone has any idea for this???
thanks!!

 

[ski]

When you say "poor image", do you mean the display is 640x480 resolution similar to the display in Safe mode?

If so, then can you select different resolutions and color depths in 'Display Properties', or just 640x480 and 16 colors?

If you can select just 640x480 and 16 colors, then you have to install the drivers for your video card.

If you can select different resolutions and color depths, then try High Color(16 bit) or True Color(32 bit), and a higher resolution.

 

[luciodandrea]

no, by poor image i mean that, i see the desktop in the appropiate resolution (that is 1280x1024) but it's kinda fuzzy and dark....it's like, it's ALMOST there, but there's something or a parameter that i'm missing or i'm configuring in a bad way....
i really don't know what else do...

 

[felixc]

If your powerstrip really controls the video parameters (although I doubt it) , try moving the position of the Hsync signal a bit, or add some time between the Hsync and the start of the next line. It may have to do with the automatic clamping of the monitor.

I see that this monitor uses 3 BNC conenctors? Are there also separate BNCs for the sync signals? Or is it a "sync-on-green" type?

 

[luciodandrea]

that's right felix, it uses a 3 bnc connector, and syncs-on-green....although,powerstrip has the option to specify the monitor as sync-on-green and fixed frecuency, but the appear to me as greyed-out optionss...don't know why...maybe because the program takes the monitor specified under windows....i'm not sure on this....

 

[garebo]

This may not be applicable but isnt there sometimes specific drivers available for certain monitors?
Perhaps you could download the monitor driver from the mfgr website. I'm not sure if this would help anyway but you seem to be stuck and i am only trying to help.
I know i downloaded a driver for a monitor a long time ago and it did help out, but it may not have been the monitor driver, maybe just a certain setting or error on my part.
Worth a try to have a look at the mfgrs website. There might even be a FAQ there or some specific info on that monitor. It may be in an archive section by now if its an older monitor.




Good advice + great people = tek-tips

 

[KevinADC]

That monitor will probably give you a headache and eye strain if you use it too much, the fixed frequency is very low (60hz /63 hz I believe) so the montior will have very noticeable amounts of flickering. Considering that monitor is probably 12 to 13 years old, it might just be worn out. I hope you have it on a sturdy desk or table, if that giant falls over it might kill you!

 

[felixc]

Many monitors of this type had a more persistent phosphor to make the image still comfortable. It may be the case with yours.

Sync on green is not part of the VGA standards. The syncs come as two separate digital lines. Your monitor may just be trying to sync on the signal itself, thus explaining the bad image.

Not everybody has a scope to check a video signal, this would be the easy way to see if there is a sync signal on your green channel. Since your image is bad I suspect that there is none. I never heard about a dongle that does this conversion for cheap. But there are some places on the web talking about it. It is not just connecting wires, there's a bit of circuitry in it. To make things worse, the polarity of the sync signals changes with the different resolutions settings. This was a way to tell the monitor to change to a different set of scanning parameters.

Sync-on-green monitors also have a clamping circuit to reference the black levels. The video signal timing must have a free zone to sample a black level. If you monitor does not catch a sync properly, the clamping can be done in the active video area, fooling the intensity levels on a per line basis.

In short, the modern PCs assume that your monitor has multi-syncing capabilities. Not Apples or Suns.

 

[luciodandrea]

thanks for all the advices so far....
felix...vey useful info...now, i can see my desktop in the monitor, but as bad image i mean that is sort of dark...and a bit fuzzy in some areas....
look, there's a guy at

http://www.lysator.liu.se/~wallman/ibm6091.html

who worked it out to make it work...i used to had another link with many ways to do this on windows, but i think that i have it into my work's account....so, as soon as i find it i'll post it....

 

[luciodandrea]

one thing that i forgot! do you mean that i can make it work with an apple computer??? i'm an apple user, since at work i have a winbox....but i'm always carriyng mi ibook..so i could give this a try with the ibook...(G4 model)
what do you think????

 

[felixc]

Some old cards, I remember that Matrox had some, did have a sync-on-green option. Maybe that the S3 card of this person had it too. If you can't find a means to get this sync-on-green, you will lose your time. I saw a couple of adapters on the web, but at close to $200. it is not worth it, since you can now get 19-inch monitors at this price.

Dark and fuzzy is exactly what happens with all that I described before. The black reference is sampled in the video, so everything displays too dark, and it probably varies depending on what is displayed on screen.

Apples are making less use of multi-syncing, as they never tried to emulate the modes of the previous generations. But I don't know if they have sync-on-green.

It is frustrating to own something that is in good working condition but that you can't use. But even if I know how to make a circuit to provide the sync-on-gteen, I would not even bother making one because this monitor does not have multi-sync.