Swap some SIMMs around and see if you can get the error to go away. By process of elimination you should be able to figure out which stick is bad. Or it could just be corrosion, and moving the sticks in and out will fix the problem. Be very careful to avoid snapping the plastic retaining tabs on the RAM sockets as they tend to be quite brittle nowadays.

Never seen an extended ISA slot like that, but I've heard many manufacturers were experimenting between the 16-bit ISA era and the VLB era, so likely it's a proprietary slot for increased video card performance. Good luck finding a compatible card, but if you do, hold onto it as it will be somewhat of a rare curiosity.

If you mean the board is an L-shape then that's fairly common. Often earlier boards of a given technology type tend to be that shape.

The long slot is almost certainly for a proprietary 32-bit memory expansion. This type of board normally only accepts 256k and 1MB SIMMs.

Malvineous wrote:

Swap some SIMMs around and see if you can get the error to go away. By process of elimination you should be able to figure out which stick is bad. Or it could just be corrosion, and moving the sticks in and out will fix the problem. Be very careful to avoid snapping the plastic retaining tabs on the RAM sockets as they tend to be quite brittle nowadays.

That was my planned approach and thinking as well - the trouble is that the power supply is floating over the SIMMS, so I am going to have to more or less de-case the thing in order to troubleshoot.

Anonymous Coward wrote:

The long slot is almost certainly for a proprietary 32-bit memory expansion. This type of board normally only accepts 256k and 1MB SIMMs.

That is what Google searching seems to produce - although with not very concrete results. I am still not sure if there is a fancy name for it or not. I have only seen some memory boards that appear to have that extra length.

I'll re-seat the SIMMS when I can. If I can get past the BIOS beeps, I can try to get some info on which motherboard it is.

If you unscrew the PSU from the case (assuming it's only in with the four screws on the back), you should be able to angle it such that you can get to the SIMMs without unplugging anything, so you can switch it on to test it without having to remove the motherboard from the case. I've done this a number of times as the path of least resistance!

EDIT: Looks like the motherboard is an EVEREX 3000 K/L or possibly from the "1851B" marking on the BIOS chips, an EVEREX SYSTEM 3900 (EV-1851), which would mean that Anonymous was right, and the extended slot is indeed for a memory expansion card.

Ooooh. Looks like the EVEREX 3000 K/L based on the space between the SIMM slots (6 together + space + 2). Thanks, Malvineous!

Indeed - I will probably unscrew the PSU - possibly even remove it completely & Use another one with longer wires.