First post, by Nathan_A
Hi,
I've recently acquired an OrangePC 620 "PC Compatibility Card" for a vintage computing project I'm working on. I've been able to get it working with the stock WinChip 200 CPU and a Pentium MMX 233. I acquired a couple of AMD K6-III+ CPUs to try with it since the card supports the non-"plus" versions of the K6-2/3. Both my AMD CPUs are the 2.0v variant, so I set the OrangePC card to its lowest 2.1v setting, which should still be in-spec for the chips.
Insofar as I understand it the "plus" versions of the CPUs often required special BIOS support in order to work. What I don't know is why (like what was special that required these updates?) and also what would happen when you'd use these CPUs without that BIOS support (like would they boot at all? not POST? etc.).
In my particular setup there's an application on the host computer that you launch and it basically boots the card. There's no BIOS on the card itself. Instead the CMOS and BIOS are stored inside the application executable and they're fed to the card at launch. Normally what happens with any working CPU I put in there is that I launch the application, the card switches over to the PC Compatibility card's VGA output, and then I see things POST, boot, etc.
With either of the K6-III+ CPUs the video never switches over and the host application hangs for awhile with an "Initializing..." message until finally timing out saying that the card isn't responding properly (this is the typical behavior when you've misconfigured something that has no obvious recovery path, like not installing any memory, selecting a bad clock multiplier on a CPU that doesn't then default to something sane, etc.).
I've actually extracted the Award BIOS image out of the application executable, run it through BIOS Patcher 4.23 to "Add newer CPU support" and then reworked that patched BIOS into the application, but it didn't change the behavior described above at all.
So, I guess I'm trying to sort out if the CPUs themselves are borked, or if I just haven't dug deep enough into getting them working by updating the BIOS image.
Cheers!
P.S. When I get back to my computer (currently typing on my phone) I'll also post the extracted BIOS file for posterity.
EDIT: I've attached the "Award SiS 5597/5598" BIOS image that I extracted from the resource fork of the OrangePCi 3.4.x application.