Help identify this beauty of 386/486 board \ VOGONS

Help identify this beauty of 386/486 board

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First post, by ykot

Posted on 2020-06-29, 23:33

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I have just got a compact AT case powered by this beautiful working board. However, I am quite surprised and unfamiliar with this layout. It seems to be using Cyrix Cx486DLC as CPU and Cyrix FasMath CX-83D87-33 GP as co-processor. In the BIOS it also mentions 128Kb of cache.

Am I correct to think that this is actually a 386 motherboard using 486 processor?

I have immediately unsoldered the barrel battery, which already started to leak acid on one side, and see there is a 4-pin jumper labeled "EXT_BAT", with a jumper in the middle pins of 2-3. What would be the meaning of these pins?

There is also another jumper on right side labeled "JP4" - would be interesting to know what it controls.
By the way, this thing is so small - probably smaller than a Mini-ITX factor. Under one of ISA slots it says "G W386/486 MAIN BOARD".

Edit: updated photo after desoldering barrel battery and cleanup, and attached BIOS dump.

Last edited by ykot on 2020-06-30, 02:04. Edited 1 time in total.

Reply 1 of 10, by Deksor

Posted on 2020-06-30, 00:04

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I think I've found it : http://www.uncreativelabs.de/th99/m/U-Z/32922.htm
The ext bat connector is to connect an EXTernal BATtery ^^

If it start, can you show us pictures of the POST screen or even better, send us a dump of your BIOS ?

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

Reply 2 of 10, by Anonymous Coward

Posted on 2020-06-30, 00:08

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Nice 486DLC. It has some pretty unusual OEM markings.

"Will the highways on the internets become more few?" -Gee Dubya
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium

Reply 3 of 10, by Horun

Posted on 2020-06-30, 01:00

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Yes it is a very odd OEM label, no luck in searches. Wonder who TI built those for, or did they (OEM) just remove TI or Cyrix label and add their own logo.... curious !

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 4 of 10, by cyclone3d

Posted on 2020-06-30, 01:32

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Looked up CDCOM International Inc. and it looks like they were an importer and reseller.

Seems they had a shipment of VGA cards seized in 1996 by US customs due to the mfg having a counterfeit MS logo on them:
https://books.google.com/books?id=Q7xrzP4cit4 … %20inc.&f=false

https://www.corporationwiki.com/Florida/Miami … nc-4370769.aspx

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Reply 5 of 10, by ykot

Posted on 2020-06-30, 02:10

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Thank you for identifying this motherboard, I really appreciate it.

I have edited my initial post with BIOS dump and updated the photo. I am attaching here BIOS startup screen and some benchmarks. I couldn't run CCT386 as it would crash with "exp overflow", similarly HWINFO would crash with "exp overflow" during FPU benchmark. SpeedSys takes too long to benchmark CPU so I'll run it later. Curiously, NSSI identified FPU as "Internal Emulator"?

By the way, on the aforementioned web page with the jumper information, chipset is described as "unidentified", but looking at some chips it seems to be UMC.

Edit: it looks like these benchmarks were performed with NPU disabled by JP7 jumper, enabling it eliminates CCT386 and HWINFO crashes and improves NSSI - FPU benchmark, I'll upload those later...

Reply 6 of 10, by evasive

Posted on 2020-06-30, 06:37

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Amptron DX-5800 aka PCChips M3** (previously thought to be the M326 but that has a different layout and chipset).

Here's another (Amptron/PCChips) CDCOM offering in another thread:
M396F motherboard

Reply 7 of 10, by evasive

Posted on 2020-08-01, 12:10

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Found some new info:
Amptron DX-5800 = PCChips M326 rev below 5
Amptron DX-5800B = PCChips M326 rev 5 and up

Reply 8 of 10, by ykot

Posted on 2020-08-03, 17:36

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Thanks a lot! This has been running great so far, very fast and stable. I have ordered an AMD 386 DX/40 along with its co-processor (which already arrived) to try with this motherboard and see how it performs in comparison to Cyrix.

Reply 9 of 10, by Tunguska

Posted on 2022-03-26, 22:30

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Thank you for the BIOS dump, I have this same MB but the bios chips is broken.

Thx!!!

Reply 10 of 10, by evasive

Posted on 2022-04-14, 11:21

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It's slightly different from the M326 3.1, enough to give it an own page here:
https://www.ultimateretro.net/en/motherboards/11200

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