BIOS firmware must be Phoenix 09-00065 1.10 Mxx (PHX 1.10 M11 from dual Eprom 27C256 or dual Eprom 27C512)

Well I couldn't find the original Phoenix BIOS for that board, but I did find what appears to be an MR BIOS for the Micronics 36x chipset. Perhaps you can give this a try and see if it revives that board.
https://www.dropbox.com/s/qivgt6kan5mdthy/386 … 20BIOS.zip?dl=0

Thank you very much! I very hope that it will work. Now I'm waiting my package with new Eprom Am27C256 and Eeprom W27C512 .

I should mention that both files are sized to fit the 27C256 ROMs.
I can also send an unsplit image (single 64K, or 27C512 size) if you wish.

Thanks. I have a question - if I want to use only one chip Windbond EEPROM W27C512 (64 kbyte), so can i install W27C512 (with combine firmware odd+even 32 kb + 32kb) into U2 DIP-place ? Or I must install into U2 DIP-place one chip W27C512 (with dual firmware ODD 32kb+32kb) and the second chip W27C512 (with dual firmware EVEN 32kb+32kb) into U3 DIP-place?

The board we have in UH19 has both sockets populated: http://www.win3x.org/uh19/motherboard/show/3701

I assume the BIOS image is spit between the two chips, one for ODD and the other one for EVEN.

Yes, I split the BIOS image into .ODD and .EVEN portions. Burn one 27C256 for each image. I don't know which socket is ODD or EVEN though (just try swapping the chips around if it doesn't work the first time).

Unfortunatelly not working with this bios, perhaps this BIOS for another PCB. ( No screen image, only beep signal code at start - 1 Long and 3 shorts, all another components (RAM, Video is OK) )

Bummer 🙁 But not all hope is lost yet...

1 long 3 short sounds like a RAM failure code. The RAM may be okay in and of itself, but perhaps that board needs jumpers or DIP switches to be set to indicate the amount of RAM installed. I had a discrete-logic 486 board that required me to set jumpers to tell it how much RAM was installed.

Indeed, TH'99 has this to say about the jumpers to set. https://stason.org/TULARC/pc/motherboards/M/M … 80386-ASIC.html

Thanks. Today I tryed to start MB with several combinations of memory jumpers but no result - the same problem (no video initalization). I think that BIOS of 386 ASIC not compatible with PCB of this board. Board 386 ASIC have some less chipsets (TACT82206FN not available for example).

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

computerguy08 wrote on 2020-11-11, 17:38:

The board we have in UH19 has both sockets populated: http://www.win3x.org/uh19/motherboard/show/3701

I assume the BIOS image is spit between the two chips, one for ODD and the other one for EVEN.

It's possibile to find or download BIOS of this board?

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

I had this suspicion for a while that Micronics were rebranding existing chipsets under a license, If MIC 36x chipset is actually a C&T PEAK chipset, then i wonder what a MIC 471 could possibly be. MIC 471/491 chipset accepts EDO RAM, supports WB caching scheme, has VLB support but no PCI and no integrated IDE controller or RTC/CMOS, it also allows to slow down system with a key combination, any ideas what it could be? I think that it might actually be a SiS 85C471/85C407 chipset in disguise, I'll have to investigate this theory later...

It might be. I too doubt Micronics built their own later chipsets. I have thought this too about the 4xx chipsets, but I have no leads. There is also a 472 chipset, no idea what that is either. Would love to have a Micronics to OEM chart but it looks like this information is lost to history. At best we may be able to do BIOS substitutions and make guesses based on pinouts. It may be Micronics benchmarked various chipsets, picked the fastest and slapped their name on it.

A MIC 471 is a rebadged SiS 85C471. I have a Micronics JX30G VLB board with this chipset, and it works with the SIS471 config file under CTCHIP.

Late edit: Actually it's an SiS 85C461. A bit similar, but there are some key differences!

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.

I've also tried few BIOS images from other motherboards that used SiS 85C460/461/471 chipset and these are the results:

"ABIT AB-AV4", AMI BIOS 06/06/92, 85C460 chipset - POSTs, but after entering BIOS setup, system either freezes or keyboard stops responding.

"Soyo SY-025D2", AMI BIOS 08/08/93, 85C461 chipset - POSTs, but after entering BIOS setup, system either freezes or keyboard stops responding.

"Asus VL/I-486SV2GX4", Award BIOS, 11/19/97, 85C471 chipset - does not POST.

A MIC491 = SiS 85C407 ISA bus buffer. I think that MIC 472 must be a SiS 85C471, because motherboards that use this chip usually have DIP 32 cache sockets and the main difference between a 85C460/461 and a 85C472 is that the latter can cache a wider RAM area (64MB vs 128MB), thus it makes sense that boards with MIC 472 have a better cache upgradability. There also exists a MIC 4716 chip, it probably also belongs to SiS 85C4xx chipset family, or maybe it's a Opti 82C499, who knows...

datasheets:
85C460
85C471

Well, that is pretty interesting. That might explain why datasheets for micronics chipsets never show up.
I like Micronics boards for their excellent PCB quality, but they always have the worst BIOSes. Maybe now that can change...

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

Thank you very much for advice and information. So, this board will work with AMI BIOS C&T PEAK/386: AT (Cached) (82C311/82C315/82C316)? I just only found for C&T Unknown board 82C301C, 82C302, 82C303, 82C304, 82C305, 82C306, 82C206 AMI BIOS and (AMI BIOS) for C&T PEAK/DM BOARD.