Regarding wire patches - there are three main differences between our boards, your MB lacks a wire patch between U56 pin 76 and RP27 pin 6 and a patch that links U26 pin 2 with pin 10, also, your board has a link between U19 pin 9 and U39 pin 6, which my board lacks. Perhaps link U56->RP27 is …

High-res photos of the board. The forum kept trying to recompress them, so they are in .ZIPs.

I was able to successfully update the BIOS to 2.03 using the file located at: http://www.sandyflat.net/digerati/ast486/drivers/s-bios/05508313.exe I opened the self-extracting archive in 7Zip, extracted the DISK.IMG, and used WinImage to write it to a diskette. After that, update was performed …

Glad it worked for you! The chassis of the computer is stamped 03-12-1993, but I couldn't see any markings on the PCB to indicate what date/revision the motherboard might be -- I'll try to upload some high-res photos a little later and maybe you can figure it out. Mine does not have the integrated …

I just unearthed a Premmia 4/33 the other day and came upon your post while I was looking for more info. I've pulled the BIOS chip to make a copy, but unfortunately the lettering has been rubbed off; from what little I can still read, I'm assuming it's a PT28C020. Attached is the dump with this …

I recall looking into this Innoventions company 10 years ago. I was considering buying their SRAM tester, which according to their support e-mail, was able to test the SRAM's response time. I think to within 8 or 10 ns. This would be useful for quantifying the response time of these Chinese …

I admittedly didn't read all 18 pages of this thread, so apologies if this was already answered -- Could you run other Socket 7 processors in this system like a K5 or K6? I dug through all the other Socket 7 CPU datasheets I could find and near as I can tell the Pentium and Pentium MMX are the only …

RAMCHECK is a piece of test equipment for testing DRAM, made by the (as of earlier this year) now defunct Innoventions, Inc. In the most basic mode it will do a function test and report back the basic stats of the stick -- both what it's jumpered/programmed for, and what it actually tested as. A …

Feipoa, I could have sworn I scoured the whole thread, but I must have missed the discussion about APM. I did actually notice that it was enabled, but didn't think anything of it. I will try that and see what happens. You are correct that the PT6501A technically can't handle the power requirements …

I purchased one of these from the same seller and wanted to share my random findings, mainly just to document what I've learned for others who stumble upon this forum post as I did. I have installed two SL27S 233Mhz MMX processors without interposers -- we used to do this quite a lot back in the day …

Signed up specifically to post this since I wasn't sure how to share the info otherwise. Not sure if this one has already been found, but I recently found a MR BIOS chip on a motherboard marked SM 486-50USC. This board has a UMC UM82C491F chipset. The MR BIOS ROM chip is hand-marked 1150USC. The …