Using an IBM 8514 monitor on a modern system

[andy]

I bought an IBM 8514 monitor last week. It's in good condition, but desperately needs some new capacitors. Having no luck getting any of my modern systems to output 1024x768 87 Hz interlaced, I decided to try making an EDID adapter for it. This will allow a modern video card to read the monitor's capabilities over the DDC.

I used Analog Way EDID editor to create the EDID:
https://www.analogway.com/americas/products/software-tools/aw-edid-editor/

I started with the EDID from a "modern" CRT, and removed all the modes the 8514 can't display, and then added the 3 that it can. I also changed a few other minor things like the model number, and programmed it to a 24C02.

I built a quick and dirty VGA pass through from some extra connectors, and soldered a 24C02 to the appropriate pins of the VGA plug.

Windows now displays the correct video modes, including 1024x768 interlaced. Interestingly, it also allows 800x600 interlaced, and the monitor does sync to it. I haven't figure out what it's doing there since the 8514 doesn't support 800x600.

The Windows 7 boot screen is out of sync, but it comes into sync as soon as the desktop appears. I can't judge the picture quality of the 8514 because of the bad capacitors and need for some adjustment.

 

[VERAULT]

Wow, this is great. Doesnt look all that difficult and the picture is nice for the vintage. Good job.

 

[andy]

The bad caps are three 33uf 10v surface mount electrolytics on the video amplifier board. Fortunately, they didn't leak too badly, so there was no damage to the board. After replacing them, there is no more smearing. I spot checked some of the other caps, but didn't find any bad ones, so I'll leave them alone for now. It doesn't appear to have been used heavily.

Between the long persistence phosphor and soft focus, you can hardly tell it's interlaced.

 

[bear]

The bad caps are three 33uf 10v surface mount electrolytics on the video amplifier board. Fortunately, they didn't leak too badly, so there was no damage to the board. After replacing them, there is no more smearing.

I have two 8514s waiting to go on the bench for more or less the same problem. That'll save me a lot of effort. Thanks!

 

[andy]

Here's an improved EDID with 1024*768 interlaced added as the preferred timing. Previously, I left that blank, but some systems had problems. A Windows 10 system I tried would consistently blue screen as soon as it detected the display! Seems like a serious bug if a faulty EDID can take down the whole OS.

Now, even a Mac Pro shows the boot screen until the driver loads, then it goes blank. I assume the driver doesn't support 1024*768 interlaced. Modern systems pay close attention to the EDID since many flat panel displays can only handle a few specific resolutions. Some older flat panels had no scaling ability and could only accept their native resolution (such as the older Apple Cinema Displays).

 

[scroeffie]

i also have this monitor got if for free i have the same smeared problem in the middle of the screan i replaced the 3 33uf 10v caps no change stil the same problem

 

[andy]

Did you clean the board around the leaking capacitors?

 

[scroeffie]

Did you clean the board around the leaking capacitors?

yes i did but i found out my problem digausing is not working