This is a micro ATX case, you can't fit any ATX or Baby AT motherboards in there.

Here's a list of micro ATX super socket 7 boards :
http://www.win3x.org/uh19/motherboard/result/ … atformTypeId=42

Now I'd say you should get a real ATX case instead. This would be the easiest solution.

Aopen feels forgotten....
https://soggi.org/motherboards/aopen/MX59-Pro.htm

Thanks for the advice.
In this case i will look into buying a new case. Do you have any other advice when looking for a case for a retro computer?

Ah yeah, look at that, Gigabyte did a few, among others... http://www.win3x.org/uh19/motherboard/show/6787

dinth wrote on 2021-08-25, 15:28:

Thanks for the advice.
In this case i will look into buying a new case. Do you have any other advice when looking for a case for a retro computer?

Any ATX case with 7 slots will probably do except that maybe some of the later/newer ones need some extra holes drilled in the internal side panel for the screws to hold a baby AT motherboard like your P5A-B. I can imagine that some case manufacterers stopped offering 'AT compatibility' after some point.

PARKE wrote on 2021-08-25, 15:55:

dinth wrote on 2021-08-25, 15:28:

Thanks for the advice.
In this case i will look into buying a new case. Do you have any other advice when looking for a case for a retro computer?

Any ATX case with 7 slots will probably do except that maybe some of the later/newer ones need some extra holes drilled in the internal side panel for the screws to hold a baby AT motherboard like your P5A-B.

Another option could be to use the plastic (AT?) standoffs when the ATX case's side panel does not have a screw ipening in the appropriate place.

I can imagine that some case manufacterers stopped offering 'AT compatibility' after some point.

This is totally the case btw (no pun intended 😜 ). Only the oldest ATX cases will typically offer the mounting openings for AT motherboards.