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EGA video corruption?

offensive_Jerk

offensive_Jerk

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So I hooked up a EGA monitor to my IBM AT for the first time.
I was previously using a IBM CGA 5153 Monitor.

The hardware for the computer is the same. I'm running a IBM EGA card. Previously, I had the dip switches on the card set for CGA operation.
I hooked the EGA monitor up to my AT and noticed the quality should have been better as the resolution still looked low and the text looked interlaced.

That's when I turned the system off and changed the dip switches on the card for EGA mode. ( EGA │ 0 1 1 0) as per this thread. (although ON/OFF seems to be reversed on these switches.)
http://www.vintage-computer.com/vcforum/showthread.php?7622-IBM-EGA-card-DIP-switch-settings

I booted it back up and immediately noticed the text looked better. (sharper and better resolution).

I then wanted to fire up a game. I booted up Commander Keen 1 and the prompt states EGA detected. Then it boots to a garbled screen.
14397034402_925058b2ca_b.jpg


I then booted up a golf game.
The screen starts with some corruption. But it seems when the screen changes, the image becomes more corrupt. For instance, the image of the golfer gets more corrupt as his swing animates.
14374805126_112cf7496e_b.jpg

14394566381_fa0a3ecd97_b.jpg


And on the copy protection screen, the image gets corrupt behind where I move the mouse cursor.

14211268919_4cff3cba2d_b.jpg





Do I have bad RAM in my card? How can I tell which chip?
 
I ran the advanced diagnostics. When I run the EGA memory test, it asks how much memory, 64K? And I select yes since there are no daughterboards. The screen sort of flashes for a second, then goes back to the main menu. (not sure if that's what's supposed to happen?)
When I quit the diagnostics for the video, a line shows "Enhanced Graphics Adapter 2400" then goes back to the main menu. I'll start reading that thread mikey99 pointed to.

I ran it again and all of the other tests, and didn't see any corruption there, FWIW.
 
Is the memory on the video card socketed or soldered? If socket it would hopefully be to re-seat the chips.
 
One thing to check is if the games actually expect a 64k EGA. There may be some that don't check and assume they got 256k.

Otherwise this looks like the GFX part of the EGA is failing.
 
Seems fine in monochrome and CGA games, but anything above that seems to still mess with this card.
Can anyone tell me if Commander Keen works with their IBM EGA card with no memory daughter card?

Here's what SimAnt looks like in EGA mode.ega.jpg

Also, here's a youtube video I made of the issue, running several programs.

 
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I can verify from my own personal experience that the IBM EGA card without memory expansion will not drive many EGA games. Sad but true.
 
Keen requires EGA or VGA. No CGA. It uses high powered graphics (for its time) that when I just ran it look (intuitively) like they would never run on 64K cards. 64K EGA is just a bastardized CGA.
 
The issue clearly is the IBM card. After 6 months with no solution or memory expansion card to see if matters improve suggests the OP needs to replace his current video card with something with decent EGA support if playing EGA games/software. A quick n dirty solution is using a 8 bit compatible vga card or 16 bit vga card that'll work in an 8-bit isa slot, then use a vga monitor
 
My plan for this was to keep my 5170 using all IBM parts. I don't have the ega memory expansion board to test with. I wanted to know if the issues I have here are the same as other users get when using the card with no expansion board. If the symptoms are totally different, then I would assume the card has issues.

I was trying to figure out if I should attempt to procure the RAm expansion board for the ega card, or not to bother with it if the card is bad.

That's why I'm trying to compare my results to other people who try to run these games with a vanilla ibm ega card. I may have no choice to go to a 3rd party card, but I would like to keep it all ibm.

Also I have an IBM ega monitor that I am using with this system.
 
I tried Commander Keen part 1 on my IBM XT-286 running an IBM EGA card with the memory expansion (256K).
The first thing I noticed was the messages displayed are slightly different, and this indicates my version
number is 1.31. You should try downloading version 1.31 and see if that works any better.
I downloaded this from www.myabandonware.com

Also there is a message displayed about decompressing graphics.
The game runs fine, and I don't see any video corruption.

I do have another IBM EGA card (somewhere) without the memory expansion, I'll try that and see what results I get.
I also have a couple of other EGA cards, a VEGA Video 7 and another unidentified one, I'll see if these work as well.

IMG_3958.jpg
 
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