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IBM EGA adapter problem

souler

Experienced Member
Joined
Feb 15, 2006
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66
I have problem with this EGA adapter: http://souler.deviate.fi/ega/IMGP2439.JPG

I ran old version of CheckIt and did a EGA video memory test on it on my IBM XT and took a photo of the result: http://souler.deviate.fi/ega/IMGP2438.JPG

The question is, how do i determine which of the chips is the faulty one based on that checkit result or can i? They are soldered and not in sockets so it would be much easier to just replace the bad one than all of them :/
 
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Stone

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My first guess would be U10 and my second guess would be U40. In any case, I think it's the first chip in Bank 1 which is the second memory bank. Since the Banks aren't labeled I guessed that it's either the sceond one from the top or the second from the bottom.
 

souler

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Feb 15, 2006
Messages
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My first guess would be U10 and my second guess would be U40. In any case, I think it's the first chip in Bank 1 which is the second memory bank. Since the Banks aren't labeled I guessed that it's either the sceond one from the top or the second from the bottom.

I resoldered the U10 and U40 but no effect. I go buy new chips tomorrow and solder them in. This is stupid question but do i go much wrong if i buy these from local electronics store: http://www.partco.biz/verkkokauppa/product_info.php?products_id=1966
instead of original part which costs many times more..? (http://www.dougdeals.com/p-5313-vintage-tx-texas-instruments-tms4416-15nl-ram-16k-x-4.aspx)
 

souler

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As long as you had them out switching the U10 and U40 would have been more informative. :)

Actually i didnt, i just didn't want to stress the ~30year old PCB by ripping them out, just sucked the solder and resoldered. My plan was to just cut off the legs of the old chips and solder new ones, its more safe that way..u uknow.
Now i still did solder them out and it happened, the wires on PCB ripped off at 4 places but i fixed them with jump wires :( Now the chips are swapped but i dont know why but my keyboard's H-key stopped working and i tried it on another XT too (with the same EGA card cause its the only one i have) and still no go..:(
Can EGA adapter really cause H-key to stop working???? It has always worked before.
I cant even type "checkit" to test the mem cause it has H in it.. Now i am a really sad panda :(((
 

souler

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Feb 15, 2006
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I tried with CGA card without monitor. Blindly testing the keyboard, the H key still does not work. So i broke my XT or my keyboard. I dont understand how.. Forgot that Alt-number combination. Did checkit with using alt-104 again but almost the same result: http://souler.deviate.fi/ega/IMGP2440.JPG
But now i have this very serious issue with keyboard and now i know how i will spend my night or even more, depends how long it takes to make it work again!!!!
 

Stone

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I cant even type "checkit" to test the mem cause it has H in it.. Now i am a really sad panda :(((
You can get an 'h' by depressing and holding the 'ALT' key while typing 104 on the numeric keypad and then releasing the 'ALT' key. FWIW, you can get any keyboard character with this method, in fact you can get dozens of characters that aren't even on the keyboard this way.

Like this: ¼ ½ ¾ € ¢ £ ♥ ♦ ♠ ♣ ❤ Ø ø Σ σ Θ Ω µ .... and lots more.
 

souler

Experienced Member
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Got it to work, it was the cord. Swapped a cord from another non-working keyboard and now H is working =))) but the EGA controller still gives errors.
 

Stone

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Hey, it could be the U11 or U41 chips. At this point you might just be better off replacing them all unless you're up for one more test. :)
 

souler

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Feb 15, 2006
Messages
66
Hey, it could be the U11 or U41 chips. At this point you might just be better off replacing them all unless you're up for one more test. :)

That's what i'm gonna do.
I buy sockets and all new mem chips. I didnt get answer to my previous question are these http://www.partco.biz/verkkokauppa/product_info.php?products_id=1966 ok for this? Originals are too expensive, for example: http://www.dougdeals.com/p-5313-vintage-tx-texas-instruments-tms4416-15nl-ram-16k-x-4.aspx.. and i have to order them (wait and pay postage) which takes time and money, previous link is the local electronics store near me so i can buy them tomorrow if the chips are compatible.. I would say they are but not sure.
 
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souler

Experienced Member
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Feb 15, 2006
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The first link doesn't work. But from the link in the earlier post it looks like it should be ok.

Sorry i messed up the link and its now fixed. Thanks for you and all others who helped me =)
 

modem7

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May 29, 2006
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Melbourne, Australia
I have problem with this EGA adapter: http://souler.deviate.fi/ega/IMGP2439.JPG
I ran old version of CheckIt and did a EGA video memory test on it on my IBM XT and took a photo of the result:
The question is, how do i determine which of the chips is the faulty one based on that checkit result or can i?
I hate to inform you of this, but the EGA RAM is probably good. CheckIt is known for reporting errors if the good memory on an IBM EGA card is tested. Versions 2.1 and 3.0 of CheckIt are known versions that do that.

Usually, people become aware of faulty RAM on the IBM EGA card when the computer powers on. At that time, the IBM EGA card will perform its own self test (a crude/basic one). If the card finds a problem with itself (including RAM problems), the card will cause the speaker to beep the error pattern of 1 long beep followed by 3 short beeps.
 

souler

Experienced Member
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Feb 15, 2006
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Graphics are corrupted in FS3 and some other games which use more video memory so i thought it is the ram..
 

mikey99

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If you have a genuine IBM XT you can run the EGA video adapter test on the IBM Advanced Diagnostics
diskette. This tests the memory of the adapter...... I've used this to isolate faulty memory chips.
 

mikey99

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Graphics are corrupted in FS3 and some other games which use more video memory so i thought it is the ram..

The IBM EGA only has 64KB video memory on the card. You can add memory up to 256KB total if you have the daughtercard.

I also noticed several games that had distorted graphics when running with the EGA w/64KB. One I recall is EGATrek.
After I added the daughtercard with extra memory, the video corruption went away. I suspect these games may just
'assume' that the video card has enough memory to run the game.
 

souler

Experienced Member
Joined
Feb 15, 2006
Messages
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The IBM EGA only has 64KB video memory on the card. You can add memory up to 256KB total if you have the daughtercard.

I also noticed several games that had distorted graphics when running with the EGA w/64KB. One I recall is EGATrek.
After I added the daughtercard with extra memory, the video corruption went away. I suspect these games may just
'assume' that the video card has enough memory to run the game.

It would be a good idea to even say "Not enough video memory" or something like that =)
 

souler

Experienced Member
Joined
Feb 15, 2006
Messages
66
The IBM EGA only has 64KB video memory on the card. You can add memory up to 256KB total if you have the daughtercard.

I also noticed several games that had distorted graphics when running with the EGA w/64KB. One I recall is EGATrek.
After I added the daughtercard with extra memory, the video corruption went away. I suspect these games may just
'assume' that the video card has enough memory to run the game.

You must be right. No beeps at all, so the mem is probably fine.
I bought another EGA card which has not been arrived yet. I couldn't find IBM daughterboard from anywhere so i decided to buy that Paradise EGA card with 256KB of videoram.
 
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