SSTV2 wrote on 2021-03-18, 20:40:

I did some probing of MIC 471 chip in Micronics GJX30G-04P motherboard and it turns out that MIC 471 is in fact either a SiS 85C460 or 85C461 chip, but not a 85C471 - its pinout doesn't match MIC 471's pinout.

You actually probed every single pin of the MIC471 to determine that? According to the datasheets, both the SiS 461 and SiS 471 have 52 pins per side.

EDIT: No, shut up Eep386 about your menial misadventures. Besides, more up to date Micronics original BIOSes are available: http://www.os2site.com/sw/hardware/mb/Micronics/index.html
What I'd *really* like to see, is an MR BIOS for the board. Phoenix BIOS just flat-out sucks in my opinion.

ALessor wrote on 2020-11-30, 15:10:

Micronics 386 Baby Non Cache - PCB 09-00065-xx Rev D1 with TACT82206FN DMA controller and PCB 09-00065-xx Rev D2 with UM82C206 DMA controller

Not much help but that PCB# goes to Baby 386 SMT ASIC Non-Cache according to their old website. Am sure you already checked that.
http://web.archive.org/web/19970607125928/htt … rchives/386.htm
Somewhere have a bunch Micro Firmware BIOS files but probably mostly 486 and Pentium which would not help (and are spread across multi computers 🙁 ) will try to look this weekend...

Eep386 wrote on 2021-03-19, 23:12:

You actually probed every single pin of the MIC471 to determine that? According to the datasheets, both the SiS 461 and SiS 471 […]
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SSTV2 wrote on 2021-03-18, 20:40:

I did some probing of MIC 471 chip in Micronics GJX30G-04P motherboard and it turns out that MIC 471 is in fact either a SiS 85C460 or 85C461 chip, but not a 85C471 - its pinout doesn't match MIC 471's pinout.

You actually probed every single pin of the MIC471 to determine that? According to the datasheets, both the SiS 461 and SiS 471 have 52 pins per side.

EDIT: No, shut up Eep386 about your menial misadventures. Besides, more up to date Micronics original BIOSes are available: http://www.os2site.com/sw/hardware/mb/Micronics/index.html
What I'd *really* like to see, is an MR BIOS for the board. Phoenix BIOS just flat-out sucks in my opinion.

I had probed only power pins (GND, Vcc) on MIC chip and compared them with power pin pinouts shown in SiS datasheets and it matched the 85C460 pinout by 100%.

Thanks for reminding me about JX30G-12 BIOS, I had it on my hard drive for a while, but was always hesistant to try it, thinking that it would not support PS/2 mouse, but does it actually? Also, do you know what's the new limit for HDD capacity with it?

Sorry ALessor for derailing your thread a bit, I hope you find a matching BIOS image for your board 😉

SSTV2 wrote on 2021-03-20, 16:36:

Thanks for reminding me about JX30G-12 BIOS, I had it on my hard drive for a while, but was always hesistant to try it, thinking that it would not support PS/2 mouse, but does it actually? Also, do you know what's the new limit for HDD capacity with it?

Micronics and Diamond (who bought them) archives just say up to 2GB: http://web.archive.org/web/19980120095226/htt … os/b-jx30g.html
http://web.archive.org/web/20001028224408/htt … os/b-jx30g.html
According to Micro Firmware the -17 BIOS supports greater then 8.4Gb if I read the old website proper and the JX30GC (486 VL Bus) is also the M4HS45G.
https://www.rigacci.org/docs/biblio/online/fi … are/mfibios.htm

@SSTV2 2GB-ish sounds about right for the updated Micronics BIOSes. Of course, I never tried the updated BIOSes so I couldn't tell you if they support anything higher capacity.

It's interesting that they'd label an SiS 460, a 'MIC 471'. Perhaps Micronics was trying to upsell an older design?
What's even more interesting is that the VLB implementation on my JX30G at least, which seemingly uses the 460 chipset, performs quite well and is reasonably compatible. The SiS 460 datasheet mentions only partial VESA Local Bus compatibility at the most. (It does provide LBD and LRDY signals for local bus support.)

Good job Horun, loved that they didn't even bother to specify the exact capacity limit and instead went with "approx. 2 gigs" 😁. Exact HDD geometry limits now are 4095C/16H/63S or 2113 MB (2015 MiB), I had tested that BIOS update and it supports PS/2 mouse and system flopped to boot from a HDD, which geometry was 4470C/15H/63S. It would be nice to have a further updated BIOS image from "Micro Firmare" but I assume that not awfully many companies bothered investing money into outdated 486 systems (each BIOS update required a separate license!), just so those could support greater than 0.5/2 GB IDE drives, so chances of getting one sample are close to none I think, it would be faster to patch HDD detection part in BIOS by ourselves, than waiting for one to materialize somewhere.

Eep386 wrote on 2021-03-20, 20:47:

It's interesting that they'd label an SiS 460, a 'MIC 471'. Perhaps Micronics was trying to upsell an older design?

Could be, Micronics didn't sell those chips to third parties AFAIK and only sold a finished product, thus they could get away with the lack of chipset documentation, which would have been necessary if they had sold those chips.

Eep386 wrote on 2021-03-20, 20:47:

What's even more interesting is that the VLB implementation on my JX30G at least, which seemingly uses the 460 chipset, performs quite well and is reasonably compatible. The SiS 460 datasheet mentions only partial VESA Local Bus compatibility at the most. (It does provide LBD and LRDY signals for local bus support.)

Now that you mention a VLB implementation I remembered that by some reason I couldn't get one Cirrus logic VLB card to work on that board, it was a CL-GD5428 (IIRC) 8500VL from GENOA, no idea why it refused to work on that board.

How bizarre! Maybe the 8500VL didn't have enough silicon-chocolate sprinkles or something. (Or maybe said card was dependent on a feature that wasn't provided by the 460's limited VLB support.)
I tried a variety of cards, Tridents, S3, Cirrus, even a fussy Chips F64300, and it didn't give me grief with any of them.
It was a little glitchy with an ET4000/W32P VLB card I had, though I think that was due to the card itself. The card has issues running on other computers as well, I'm thinking it's possibly a dying chip.

mR_Slug wrote on 2021-03-17, 21:40:

Hi, I sold the board a few years ago. I had to find a bios for mine to, but i don't seem to be able to find the file i used. Search everywhere. IIRC i used a C&T PEAK/386 bios. (Not PEAK/DM). My theory is that the MIC 362, MIC 363, MIC 361 chips are actually re branded C&T PEAK/386. Though going against this theory is that that chipset is supposed to be cached. May be this board just doesn't implement that.

C&T PEAK/386:
http://66.113.161.23/~mR_Slug/chipset/chipset … 0,2&2=5250#4905

It's still hard to find firmware for C&T PEAK/386. I tryed many firmwares from others 386 board (and 286) but no result(

Attached is the PEAK/DM bios. I may have got PEAK/386 and PEAK/DM round the wrong way. Try it and see if it works. Please let me know and I will put it on the UH19 page.

Thank you very much, but unfortunatelly not working. With this Bios for PEAK DM 2.1.1 (c_t211r2.bin) - motherboard not started. Maybe PEAK DM board with cache controller that incompatible with this PCB.