First post, by lavadrop
Hi all!
A long while ago I posted that had come accross a GMB-486UNP Socket3 motherboard. Unfortunately at the time I didn't have all the components needed to put it together so I saved it for later. Before the pandemic hit, I took a look at it one day and realized the worst: it was sold to me with trace damage from a leaked battery. A week later I found a new motherboard that I also had to put off putting together because I STILL couldn't get my hands on a P8/P9 to ATX cable.
Now I have everything (I think), so yesterday evening I started the process of putting everything together and then I had to stop because there's almost no documentation about the new board I got and what's out there is a little confusing.
The MOBO in question is, apparently, a Lucky Star UCM-486V30 also called SiS SIS486B or SIS486 3-VLBUS. The only "manual" I've found is this one https://www.holm.cc/peter/motherboards/sis486 … otherboard.html
This is a picture of my actual board from another website: https://www.ultimateretro.net/en/motherboards/6823 unfortunately this website refers to the previous one for technical data.
My confusion stems from such "manual" stating less jumpers than what are actually on my board and that according to unreferenced info from the SiS entry on Wikipedia, the SiS 486 boards with the 85C461 chipset only support Intel processors and 5v AMD processors.
Unfortunately, my 486 DX2/33 is a Texas Instruments one that runs on 3.45v
I'm afraid of frying my processor. Does anyone have any more info on how to proceed?
Should I try an actual Intel DX2? a 5v AMD 486?
How do I position the front panel LED cables on their jumper pins? The cables are blue/white and green/white.
The power push-button leads, does it matter which cables are connected to them? One is green, the other is black. There are no markings on the switch.
The technical data has this section: [JP10 : CPU Version Selector 1-2 : Normal, 2-3 : for 80486 New Version]. What is normal and what is 80486 New Version?
If I understood correctly, in this case the VLB Bus speed has to be set on lower than 33 mhz, wait=0, correct?
Thanks in advanced.