Reply 30220 of 35071, by VioletGiraffe
The empty socket is for 387 co-processor. Not necessary, but optional.
For ram... Well, in the end, i have just tried out and then added sticker about the size on it. For me it has been quicker than to go through chips datasets and count together, what's the size...
First thing you want to do is to remove that barrel battery and replace it coin cell or other modern solution!
Thanks! Yep, that battery irks me, it's a miracle it hasn't leaked yet. Reading 1.6 volts across the leads, it's in best case seriously discharged,but likely just dead. Not sure yet what I'm going to replace it with as it's a Ni-Cd rechargeable and a somewhat inconvenient voltage to replace with something other than a similar Ni-Cd or Ni-MH. Maybe a small Li-Po.
Odd, I've searched for 80387 to see how it looks and pretty much all the pictures paint a chip with leads around its perimiter, not with an array of legs under the belly.
Did games of the era use floating-point math? I guess 3D ones could have. Would installing a 387 let me run something that a bare 386DX-40 can't?
It’s a fairly typical late 386 board with an integrated AMD 386DX40 CPU. The empty square slot is for an FPU, but there isn’t a lot of software that would benefit from that on a 386.
386 boards don’t have a lot of documentation online, so at best you can find jumper settings. However, boards like this don’t have many settings (since you can’t change the CPU), so you don’t really need that. Also most jumpers should be described on the board itself. Look for silkscreened text.
Fair enough, makes sense, thanks. So far I've only noticed the table for setting CPU frequency with jumpers, but I don't think the board has too many jumpers either. I vaguely recall reading something about having to configure IRQs with jumpers so I wanted to have the manual for that case, but I don't know if this hurdle applies to this particular mobo.