First post, by stamasd
I said I probably wasn't going to post about this system, but I ran into some problems so here we are.
MB: FIC VA-503+, PCB 1.2a
CPU: K6-2+/570 (95FSB, 6x mult, 2.0V)
mem: 2x128MB PC-133, Kingston (yes overkill but that's what I found)
vid: ATI Rage Pro AGP 8M
CF card and gotek for drives.
Should be easy enough right? Well at FSB=95, mult=6 and 2.0V, it didn't POST.
I have determined the following by trial and error:
FSB=66, 2.0V: POST and boots and works fine at any multiplier from 2.5 to 6
FSB=75, 2.0V: POST and boots and works fine at any multiplier from 2.5 to 6
FSB=83, does not POST at any multiplier and any voltage from 2.0 to 2.2V
FSB=95, does not POST at any multiplier and any voltage from 2.0 to 2.2V
FSB=100. does not POST at any multiplier and any voltage from 2.0 to 2.2V
Now, that motherboard came with a very old BIOS revision (1.13JE12) so one of the first things I did was flash it to JE4333 (latest). Before the flash, it would recognize the CPU as "486-S at 66MHz" regardless of the actual speed of the CPU (it showed up as what it really is in utilities like Landmark though). After the flash, it recognizes it properly at POST. For instance, at 75/6X it shows it as K6-2+ at 450MHz. This is the highest speed I have achieved in this system so far.
I don't know why it doesn't work at any FSB above 75. I don't have any other SS7 motherboard handy to test the CPU. I probably have other chips that I could test the motherboard with, but I have to find them and pull them from the mountain of boxes in my basement. I know for instance that I have a Cyrix MII-366 which should do 250MHz at 100/2.5x/2.9V. But I have yet to find that one.
I/O, I/O,
It's off to disk I go,
With a bit and a byte
And a read and a write,
I/O, I/O