looking for newer/alternative bios for SiS 486G ver E motherboard \ VOGONS

looking for newer/alternative bios for SiS 486G ver E motherboard

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First post, by Deksor

Posted on 2018-09-02, 23:20

Deksor Offline

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Hi folks !

This motherboard was given to me recently, and I'm currently improving it by adding/replacing missing)dead components (battery, cache, regulator). The performance is great, but I find the BIOS kinda lacking ... Mine is from July 12th of 1994 and was made by award, but apparently some newer ones were made as well as an AMI BIOS. So the question is : does anybody have any of these ?

The bios supports write-back mode for L2 cache, but so far I couldn't enable write-back on L1 cache (maybe I have to do this with jumpers, but I couldn't find it at the moment)

Can anybody help me ?

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 1 of 4, by 8bitbubsy

Posted on 2020-11-12, 19:40

8bitbubsy Offline

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I have no idea if you still have this board, but try this, dumped from my SIS 486G ver:E (non-cheapo version with socketed chips and real L2 cache chips). It's from 28/07/94.
https://16-bits.org/etc/sis486g_ver_e.bin

This BIOS has a setting for internal cache mode (write-through/write-back), and I've confirmed that it works here with WBTEST.COM (cx486wb.zip) on my Cyrix DX2-66 CPU.

Last edited by 8bitbubsy on 2020-11-12, 19:46. Edited 1 time in total.

386:
- CPU: 386DX-40 (128kB external L1 cache)
- RAM: 8MB (0 waitstates at 40MHz)
- VGA: Diamond SpeedSTAR VGA (ET4000AX 1MB ISA)
- Audio: SB Pro 2.0 + GUS 1MB
- ISA PS/2 mouse card + ISA USB card
- MS-DOS 6.22 + Win 3.1
- MR BIOS

Reply 2 of 4, by Deksor

Posted on 2020-11-12, 19:46

Deksor Offline

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Rank: l33t
Posts: 3388
Joined: 2016-06-07, 14:37

I do !!
Your bios is slightly newer than mine (just a few days) but anyways, it may work 😀
Thank you very much !
I have added it here http://www.win3x.org/uh19/motherboard/show/5549

Trying to identify old hardware ? Visit The retro web - Project's thread The Retro Web project - a stason.org/TH99 alternative

Reply 3 of 4, by 8bitbubsy

Posted on 2020-11-12, 19:47

8bitbubsy Offline

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Posts: 164
Joined: 2015-05-29, 14:49
Location: Norway

Cool! Let me know if you manage to get write-back working.

Reply 4 of 4, by 8bitbubsy

Posted on 2020-11-27, 15:35

8bitbubsy Offline

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Posts: 164
Joined: 2015-05-29, 14:49
Location: Norway

I modified the BIOS to enable L2 "Dirty Tag" when in L2 write-back mode. This means that you prevent some memory bandwidth loss while WB is enabled for the external cache.
https://16-bits.org/etc/sis486g_ver_e_mod.zip

Some apps wouldn't even register that you had L2 cache when external cache WB was enabled in the original BIOS. They do now.

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