Why do you think you need any drivers?

I would like to enable the WB cache, which to my understanding only works with the provided driver loaded.

EDIT: Wrote WT instead of WB, the WT cache works fine.

What motherboard do you use?

Check the current settings with programs like CHKCPU, NSSI, SPEEDSYS, CACHECHK

It is a Biostar MB-1433/50UCV-E. All cache checking programs report WT cache regardless of jumper setting on the chip.

EDIT: Mistyped model number.

sniper257 wrote on 2023-03-18, 18:36:

both of which do not detect my AMD 5x86 upgrade.

sniper257 wrote on 2023-03-18, 19:26:

I would like to enable the WB cache, which to my understanding only works with the provided driver loaded.

The cache on the AMD 5x86 is hardware controlled only. You can't toggle between write-back and write-through mode using software. Drivers to enable WB cache is only a thing on Cyrix/IBM/ST processors, both the 486 series, as well as the 5x86 and 6x86.

Curious if you are using a true Evergreen cpu upgrade ?

mkarcher wrote on 2023-03-18, 22:05:

The cache on the AMD 5x86 is hardware controlled only. You can't toggle between write-back and write-through mode using software. Drivers to enable WB cache is only a thing on Cyrix/IBM/ST processors, both the 486 series, as well as the 5x86 and 6x86.

Thank you, I guess my understanding was wrong. My board must just not support WB cache, oh well.

Horun wrote on 2023-03-19, 00:30:

Curious if you are using a true Evergreen cpu upgrade ?

I'm pretty sure it is. Here is the eBay listing I bought: https://archive.is/Q6bdC

sniper257 wrote on 2023-03-19, 02:39:

mkarcher wrote on 2023-03-18, 22:05:

The cache on the AMD 5x86 is hardware controlled only. You can't toggle between write-back and write-through mode using software. Drivers to enable WB cache is only a thing on Cyrix/IBM/ST processors, both the 486 series, as well as the 5x86 and 6x86.

Thank you, I guess my understanding was wrong. My board must just not support WB cache, oh well.

It seems like you got https://ardent-tool.com/CPU/486_interposer.ht … erGreen_586_QFP, which does not have external logic on it. For that upgrade module, my quoted statement is correct. On the other hand, take a look at Evergreen's cache-back technology . Obviously, Evergreen also sold socket interposers with active logic in the interposer. It is possible that this active logic can be controlled by software, and it is possible that this active logic implements a limited version of L1 WB support even for mainboards that do not support L1 WB. If you had that interposer, you might need the matching ET586 tool to enable the write-back addon mode.

Hi sniper257,

I found the ET9616.EXE file in my archive! 😀
Looking at the date/time stamp on this file, I must have downloaded it in April 1997 when I was researching the various Am5x86 upgrade kits for my http://www.steunebrink.info/amd5x86.htm article.

This ET9616.EXE file appears to be a self-extracting zip-file and when I open it with Winzip, I see only diagnostic and test files, and an install program to put it on a floppy.
So this is not a driver disk. This is inline with the Evergreen586 owner’s manual, that only speaks of an ETDIAG program.

Your Biostar MB-1433/50UIV board has the UMC8498 chipset and clearly supports L1 cache WB mode. When you use the P24D jumper settings from the manual, the board should work with the Evergreen586 Am5x86 when you set the WT/WB jumper on the Evergreen to WB.

Here are the files:
Jan

Edit: updated my website link

Wow that's amazing, thank you! Good to know I don't need a cache enabler utility for this one. The manual for the motherboard I'm working off of is this one on Phil's site: https://www.philscomputerlab.com/biostar-mb-1433.html and the jumpers are currently set for the P24D but it's the same settings as for the 486DX it's replacing and CPU speed is set to 33MHz. (same jumpers as 66/100)
The BIOS detects it as a "486DX or 487SX" in this state, and everything seems to work besides the WB cache. (jumper on chip still in WB) Based on this thread: PC Chips M912 BIOS update for Am5x86 and Cyrix 5x86 I'm thinking I need a BIOS update to recognize anything newer than a DX2.

Okay, now you got me confused. 😉
You linked to Phil’s page about the Biostar MB-1433 UCV-B/C/D/E board.
But earlier you said that you have an MB-1433/50 UIV board…

These are different boards that use different chipsets. I believe the 491/493 chipset on the UCV board doesn’t support L1 cache WB.
If you are unsure which board you have, please show us a picture and tell us the BIOS_ID string you see on the first boot screen.

Jan

Oh yeah, oops! I was using Google to determine if they were Vs or Us and got it mixed up with one of the search results 😜 It is a MB-1433/50 UCV-E with the 491 chipset it looks like. I've switched the jumper back to WT cache on the chip like the manual says for stability. Here are some extra pics:

The advanced chipset settings "Auto Config Function" would make the system freeze after "Press DEL to enter setup" so I just wanted to post these settings that worked for me for anyone coming across this in the future:
Auto Config Function: Disabled
Cache Read Function: 3-2-2-2
Cache Write Option: 0 W.S
DRAM Wait States: 0 W.S.
AT Clock Select: CPUCLK/4
Memory Remapping: Disabled

With these settings I am getting a Speedsys score of 48.12 and 10.0 FPS in Quake timedemo.

Does everything else look right in Speedsys?

Just for 💩 and giggles I've set the bus speed to 50MHz and set the multiplier jumper to 3x... it is now running at 153MHz 😁 with 52.78 Speedsys score and 11.8 FPS in Quake timedemo 😁 😁
I had to set Cache Write Option and DRAM Wait State(s) to 1 W.S. but the performance is still higher. Also set AT Clock Select to CPUCLK/6.

Allright, the Biostar MB-1433/50UCV-E PCB VER:2 motherboard it is! 😉

This board is very well suited for the Evergreen586 Am5x86 upgrade kit. You even got it up to 150MHz!

The BIOS recognizing this CPU as a 486DX is fine. Because the UM82C491F chipset needs the CPU to run in L1 cache WT mode, specific BIOS support isn’t required and you shouldn’t need a BIOS update.

Cheers, Jan

Thanks for all of your help. It runs like a champ! I can actually sort of play Quake 😄 and Doom runs about as well as it can. Is there much risk of damage with a 17MHz overclock?

sniper257 wrote on 2023-03-20, 16:03:

Thanks for all of your help. It runs like a champ! I can actually sort of play Quake 😄 and Doom runs about as well as it can. Is there much risk of damage with a 17MHz overclock?

Don't worry about the overclock. A lot of people are running the 5x86-133 at 160MHz constantly, and were already doing so back in the 90s. As long as you provide sufficient cooling (airflow is usually required), and run at 3.3 or 3.45V, you should be fine. I wouldn't dare to claim a constant overclock at 3.6V is unproblematic, but likely it is. Use more then 3.6V only if you can accept premature failure of the processor. There are people running specific seleced AMD 5x86 at 4*50MHz at 5V, but this is definitely not a recommended configuration, and way over the specification of that poor silicon thing.