- Welcome back to the past
- Turning on for the first time in 19 years
- (Electric) tension is needed
- Pimp my RAID
[Magyar] Now that we know which motherboard model I have, let's search for beep codes or possible solutions. As written previously, the battery holder was broken, and has been removed from the motherboard altogether.
The two soldered terminals of the battery holder are still in place - private archive
Some 486 motherboards won't post if the real-time clock doesn't have battery backup. - VOGONS forum
At more modern (or not those 'some 486') motherboards booting wouldn't be such an issue, only the BIOS would shout that the CMOS has been cleared, and that the settings have to be made. So I took a coin cell and a small, connectorless electric cable in order to make a contact between one terminal and one end of the battery directly, and make the contact between the other half with the small cable. In order to be able to do it, I had to take the chassis and move it to the other, Orion television in the living room, so that I do have room on the floor to dig into an open chassis of a powered on computer (I have to warn you, not to do it at home). And a miracle, I had picture, and it has reported that the keyboard is missing (lost or recycled during the years).
Out of curiosity, I took the Sony TV to the living room, to try it out as well. It has told me that the picture would be oversize. (Later, when digging into the manuals of that I found that the VGA resolution is unsupported on it, but the Orion managed displaying it somehow. Now, that I have my old 19" LG Flatron display as well, I see that the output is 640x350 at 70 Hz.) Anyway, now I know that the MoBo needs a battery holder. I bought one at an electronic parts' shop, and tried to solder it onto the board myself, but as I don't have experience with that, I rather gave up in order to prevent any damage. I had to search for some repair shop where they would solder it. Luckily I found one only a block away from my parents' flat, and they managed to assemble the battery holder onto the motherboard.
With that, I didn't have to carefully hold the small cable during the POST process, and it allowed me to step to the next step: using the computer with a keyboard. As said above, I don't have my original AT keyboard with its DIN 41524 5-pin connector and I didn't remember on its make and model either. Only some of its form details were in my mind, like the italic font, or the pencil holder at the top. Searching through a lot of image search results, eBay items etc. I found that it was the Mitsumi KPQ-E99ZC-12 with a 102-key Hungarian layout.
UK layout variant - deskthority.net
Let the hunt begin! Looking for this particular model with a Hungarian layout lead me to its younger sibling, the KPQ-EA5ZA which I was able to buy. So now I was able to turn on the computer, boot into the BIOS, check the settings, and after that even continue with the boot process, letting me install an operating system!
I don't remember anymore, at which step it has happened, but the computer still refused to boot or work properly. I've double checked the jumpers based on the manual mentioned in the previous post, and found out, that - probably out of curiosity - I've once overclocked the machine from 100 MHz to 150 MHz by raising the CPU clock from 33 MHz to 50 MHz. This issue has been resolved by reverting to 33 MHz.
Jumpers 6, 7, and 8 should all be shorted for the 33 MHz setting, here's the faulty configuration - private archive
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