Hello,

No, these are last minutes wiring which might weaken the motherboard.

obaltus wrote:

Hello,

No, these are last minutes wiring which might weaken the motherboard.

Not entirely sure what the hell you're talking about.

As I said in your other post (What happened to that anyways?) it's bodge wiring. Back when the XT was being designed, re spinning

boards was incredibly expensive, so in the event they missed a few connections, they would have connected those wires together in

order to make it stable and/or work. As long as the board is working, there is no worries, but I suggest taking a picture of where they \

all go in the event one detaches or is damaged so you can repair it.

Another way to tell it's a bodge, is that if it was a mod, nobody totally friggin insane enough to mod an XT board wouldn't have wire management, period.

Aha, so that's it. Board works fine. I tested it with the Advanced Diagnostics disk and it has no problems. No BIOS message at POST though. Is this normal for PC and PC/XTs? How do I see the BIOS version?

Errius wrote:

Aha, so that's it. Board works fine. I tested it with the Advanced Diagnostics disk and it has no problems. No BIOS message at POST though. Is this normal for PC and PC/XTs? How do I see the BIOS version?

Bodge wiring get more common the simpler, and yet the more complicated it gets. I've never seen an IBM PC with this, but it happens to most boards.

If you have real questions about Electronic Engineering, you can check out the EEVBlog forums, where I also post on occasion.

Yup, in the board layout profession those are called "blue wires". It was common back in those days.. That is the earlier revision PC/XT board.

The IBM diagnostic program reports:

ROS P/N: 1501512
ROS Date: 11/08/82

I assume this is the BIOS version and date? What does ROS stand for?

Maybe IBM's name for the ROM? Going by the chip datecodes, your board is an early 1984 vintage..

I want to do a more thorough memory test on it. I don't think memtest86 works. What alternatives are there?

Why do you want to run a memory test on it? Just wondering.

I like to test memory of all computers that come to me. Normally I use memtest86 but I don't think it works with such old hardware.

Errius wrote:

I like to test memory of all computers that come to me. Normally I use memtest86 but I don't think it works with such old hardware.

You know, a hardware test might be better. For other computers like the Commodore/Apple/Atari 8 bit machines, no memory testing software really was available that I know of, and none to the extent of what you may be looking for.

Is it safe to mount full length cards in the bottom slot, right next to the speaker? The speaker is almost touching the card. If it does touch, could anything bad happen?

you can always put a bit of black tape on the back of the speaker.

no, probably not. As long as there isn't any metal touching the speaker frame, then it's fine. If it did touch, anything could happen, as nobody is eager to find out.