A collection of motherboards, mostly partly- or non-functional.
Physically large, this is quite a motherboard. It doesn't work currently, there's a short somewhere on the board and the PSU overcurrent protection just trips. Fitted with a 10MHz Intel 286. Now sold.
This is the only motherboard on this page that I've brought to life successfully so far. Decoding the BIOS string with the help of https://www.wimsbios.com/aminumbers.jsp shows it to be an ECS motherboard. I'm not sure whether it was for PC use or whether it was a special as the only info I've found about it on the web suggests it might be from a Milltronics product - could it be from a CNC milling machine? It's got a soldered-on AMD 386SX-33 and has a pleasingly small baby AT form factor. Unfortunately it does have a memory issue. Using two good 1MB SIMMs it can only see 1792kB, which is odd because that size doesn't correspond to what could be expected from a bad address line. This represents a missing 256kB. Adding another 2MB resuts in it seeing 3840kB, which is also a strange size to stop at, with the same missing 256kB - presumably the same missing 256kB from the first 2 SIMMs. At this point, having tried various good SIMMs and having carefully cleaned all of the connector contacts and measured good continuity on all of them, my suspicion is that there's some kind of internal failure in the memory controller. All the same, even in this condition it's still a useable motherboard and allowed me to write a 360kB boot floppy for the Ericsson PC.
This seems like it should be a nice motherboard, it has cache RAM and all 16 SIMM slots are on an expansion card. Currently fitted with an Intel 386DX-33. Unfortunately the test PSU overcurrent protection trips as soon as power is supplied. I've removed the only fully shorted tant, but it looks like others are breaking down as soon as voltage is applied, so I'm working through them at the moment.
Bought on ebay for 1GBP, this came with a non-MMX Pentium 200MHz CPU, 64MB of RAM in SIMMS, and has onboard sound and ATI Rage 3D graphics. This has the makings of a very nice Pentium PC, and I'm thinking of making a custom shallow case for it using a slim Sun PSU I've got which should be fine with the right connectors fitted.
