TheMobRules wrote on 2026-02-14, 02:02:

douglar wrote on 2026-02-14, 00:27:

I was using the default settings. Any idea what I might be able to tweak?

You need to short pins 16-17 on the front panel header. It seems this MR BIOS defaults turbo speed to low.

That did the trick for me.

Here's how it looked after setting 2111 cache timing and 0 wait state:

I get some great results using the sis.exe tool, but things are not stable. I can try some other Simms.

Are there any memory setting that are recommended?

I also noticed this when using a Promise IDE 20630 controller--

Benchmarks were about 6300KB/s read and write using the auto transfer rate, so it was doing something.

edit -- Looks like the rom also detects Appian ADI2-VL, OPTi 611-VL, & CMD 640B-VL

Why doesn't it work on my board.. Why! 🙁

appiah4 wrote on 2026-02-23, 05:59:

Why doesn't it work on my board.. Why! 🙁

There were SIS471 "green" and "non-green" variants or something. Basically, when you scroll through motherboards in retroweb with SIS471 chipset, they all have in bios strings either a single letter in addition to SIS471, or a bunch of letters after it. But they don't overlap.

Therefore i have concluded there were 2 variants of SIS471 chipsets.

The MR BIOS shared here shows "BIOS ID" as "SIS_41G". So it's probably for the "green" variant.

appiah4 wrote on 2026-02-23, 05:59:

Why doesn't it work on my board.. Why! 🙁

Check if your board has the same SuperIO chip as well.

douglar wrote on 2026-02-22, 18:55:

I get some great results using the sis.exe tool, but things are not stable. I can try some other Simms.

What kind of instability are you experiencing? I'll try to replicate on my side.

douglar wrote on 2026-02-22, 18:55:

Are there any memory setting that are recommended?

Set Write Delay to Early, it will give a considerable boost to the write speed.

My board is the Chicony CH-471A v3.0 https://theretroweb.com/motherboards/s/chicon … h-471a-ver.-3.0

SiS 85C471
SiS 85C407

I only get a black screen when I POST with this BIOS. When I verify the EPROM in a reader, it validates fine. I am reluctant to waste another EPROM because I don't have an eraser and need to put it in the sun and let it wait for 3-4 months 😁

GigAHerZ wrote on 2026-02-23, 10:56:

There were SIS471 "green" and "non-green" variants or something. Basically, when you scroll through motherboards in retroweb wit […]
Show full quote

appiah4 wrote on 2026-02-23, 05:59:

Why doesn't it work on my board.. Why! 🙁

There were SIS471 "green" and "non-green" variants or something. Basically, when you scroll through motherboards in retroweb with SIS471 chipset, they all have in bios strings either a single letter in addition to SIS471, or a bunch of letters after it. But they don't overlap.

Therefore i have concluded there were 2 variants of SIS471 chipsets.

The MR BIOS shared here shows "BIOS ID" as "SIS_41G". So it's probably for the "green" variant.

I wonder how I can check mine? I wonder if they have any markings to tell them apart. I have the Award BIOS on the board dumped, maybe looking at that could help.

EDIT: A thought just occured to me: Maybe this BIOS does not work with UMC U5S processors? That's what I have in the board currently and tested with only that. If anyone else can test their boards with a UMC CPU to confirm it works, I'd be glad.

appiah4 wrote on Yesterday, 07:11:

GigAHerZ wrote on 2026-02-23, 10:56:

There were SIS471 "green" and "non-green" variants or something. Basically, when you scroll through motherboards in retroweb wit […]
Show full quote

appiah4 wrote on 2026-02-23, 05:59:

Why doesn't it work on my board.. Why! 🙁

There were SIS471 "green" and "non-green" variants or something. Basically, when you scroll through motherboards in retroweb with SIS471 chipset, they all have in bios strings either a single letter in addition to SIS471, or a bunch of letters after it. But they don't overlap.

Therefore i have concluded there were 2 variants of SIS471 chipsets.

The MR BIOS shared here shows "BIOS ID" as "SIS_41G". So it's probably for the "green" variant.

I wonder how I can check mine? I wonder if they have any markings to tell them apart. I have the Award BIOS on the board dumped, maybe looking at that could help.

EDIT: A thought just occured to me: Maybe this BIOS does not work with UMC U5S processors? That's what I have in the board currently and tested with only that. If anyone else can test their boards with a UMC CPU to confirm it works, I'd be glad.

I'm afraid the "A" vs "G" is the defining indicator.

I have this board: https://theretroweb.com/motherboards/s/qdi-v4s471-g
Here's also another board with updated bios for L2 cache fix: https://theretroweb.com/motherboards/s/asus-vl-i-486sv2gx4
And i remember that on my board, the "A" BIOSes either didn't boot at all or hanged during very first moments of POST. All "G" board bioses worked well. (As a result, the bios with "write-back L2 cache" on Asus and the "EFA bios that works" on QDI are bioses submitted by me)

On the QDI's board bios list, the EFA bios that i found, notice the BIOS string: "85C471B/E/G" - no "A", but has everything else. From this i conclude there are basically 2 variants (in practice) of SIS471.

The BIOS string from mine is 01/18/95-SIS-85C471B/E/G-2C4I9C21-00 So I don't know what to make of that. The board just does not POST with the MR BIOS.

Here is the BIOS from my CH-471A V3.0 in case anyone wants to submit to theretroweb.com I really don't want the hassle of going through their Discord 😁

Okay, it now got a lot more confusing and my theory does not hold water any more...

appiah4 wrote on Yesterday, 18:27:

The BIOS string from mine is 01/18/95-SIS-85C471B/E/G-2C4I9C21-00 So I don't know what to make of that. The board just does not POST with the MR BIOS.

Here is the BIOS from my CH-471A V3.0 in case anyone wants to submit to theretroweb.com I really don't want the hassle of going through their Discord 😁

submitted on their discord hassle 😉
https://discord.com/channels/7131124000599572 … 953445130338632

edit: also, for some reason on https://theretroweb.com/motherboards/s/chicon … h-471a-ver.-3.0
it indicates 1 file for bios but none is available.

appiah4 wrote on Yesterday, 18:27:

The BIOS string from mine is 01/18/95-SIS-85C471B/E/G-2C4I9C21-00 So I don't know what to make of that. The board just does not POST with the MR BIOS.

Here is the BIOS from my CH-471A V3.0 in case anyone wants to submit to theretroweb.com I really don't want the hassle of going through their Discord 😁

Discord is preferred but you can send an email. Their email address is at the bottom of the page.

By the way, are you using a POST card?

weedeewee wrote on Yesterday, 20:32:

it indicates 1 file for bios but none is available.

That's strange right? A stub for a bios entry was created but never populated with any info or file. It's fixed now that your BIOS info was added to the stub.

You should try a post card with your board. MR Bios post codes are on page 102.

https://drivers.dosreloaded.de/Books/The%20BI … OST%20Codes.pdf

douglar wrote on Today, 02:11:

That's strange right? A stub for a bios entry was created but never populated with any info or file. It's fixed now that your […]
Show full quote

weedeewee wrote on Yesterday, 20:32:

it indicates 1 file for bios but none is available.

That's strange right? A stub for a bios entry was created but never populated with any info or file. It's fixed now that your BIOS info was added to the stub.

You should try a post card with your board. MR Bios post codes are on page 102.

https://drivers.dosreloaded.de/Books/The%20BI … OST%20Codes.pdf

It's appiah4's bios, and whomever added it didn't checkmark the discord entry.

edit: oh, so you added it 😀
checked the logs.
I did notice that there was an entry on the v1.0 board revision that had the same bios string.