M-321 rev3.1 386DX40 mobo: worth restoring? \ VOGONS

M-321 rev3.1 386DX40 mobo: worth restoring?

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First post, by keropi

Posted on 2013-03-22, 13:22

keropi Offline

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Hello!

I have a M-321 rev3.1 386DX40 motherboard : http://stason.org/TULARC/pc/motherboards/I/IL … ml#.UUxYzjvIZok

As far as I can tell it has 128kb cache soldered on and a 386DX40 cpu. It suffered battery damage , it boots but complains (most of the times) on keyboard being locked or about a keyboard error... makes sense since the keyboard area is green and the kb controller socket has been affected too.

Now I have cleaned this up and thinking on repairing it (2032 battery, change the keyboard controller socket and maybe 2xISA slots if they don't clean well) but does it worth the trouble?
I can invest some time to it if it's a "good" motherboard but if it is a problematic one I can just leave it for spare parts or something...

The chipset is:
PC CHIPS CHIP5 4L04F 1282
PC CHIPS CHIP6 4L04F 1666
DC CHIPS H82C206

anyone has any experience with it? should I spend time on it?
Thanks in advance! 😊

🎵 🎧 ⏳ ⚡ PCMIDI MPU , OrpheusII , Action Rewind , Megacard and 🎶GoldLib soundcard website

Reply 1 of 5, by Great Hierophant

Posted on 2013-03-22, 13:42

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Feature-wise, the board looks excellent for a 386 motherboard. External battery support, range of speeds, 32MB RAM and 256K cache support, mono/color support, coprocessor socket, 8-bit ISA slots, Turbo button and well documented jumpers. PC CHIPS was a very common chipset maker in the 286 and 386 days, so I would suggest that any instabilities would be caused by the battery leakage and general age, not the reliability of the chipset.

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Reply 2 of 5, by keropi

Posted on 2013-03-22, 14:35

keropi Offline

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great, thanks for the info Great Hierophant! I'll try and restore it then 😁
unfortunately the 4 cache chips are soldered on board and there is no tag sram , only a socket... if I find them working I might add the rest 128kb so I have a full 256k mobo. 😀

🎵 🎧 ⏳ ⚡ PCMIDI MPU , OrpheusII , Action Rewind , Megacard and 🎶GoldLib soundcard website

Reply 3 of 5, by Jolaes76

Posted on 2013-03-22, 22:59

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I have one of these as well. It is a little slower than the Opti and Rabbit, considerably slower than the Forex, but as G.H. said, it has all necessary features for a good all-arounder. Quite stable as well. I think I have a different revision / mine has the 4 empty sockets for another 128 kb cache and the socket for write-back mode (dirty tag?)./ On my board, the jumpers are soldered down with tiny clamps in 128 kb position. I might risk cutting them thru then solder the pins in 256 kb position. Even with 128 kb write-back cache you can manage 16 MB main memory... 16 megabytes should be enough for everyone 😀

"Ita in vita ut in lusu alae pessima iactura arte corrigenda est."

Reply 4 of 5, by Scylla

Posted on 2013-03-22, 23:09

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Ooooh, that's sweet. Should I have the knowledge, I'd vote for restoring it, no doubt even on the basis that 386 motherboards are getting really scarce.

Reply 5 of 5, by aigeek

Posted on 2019-08-12, 06:09

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I just got one M-321 Rev 3.1 motherboard, it's Am386DX-40 and 64KB cache soldered on board, with write back enabled socket.

With 4MB x 4 RAM and extreme optimized BIOS setting, the memory bandwidth, ISA video and CF2IDE transfer rate are just ordinary.

There's not ISA CLK option in BIOS, as I know it has a significant impact on video and HDD transfer rate. On comparison motherboards I alway try to set ISA CLK/2 to get much higher performance (some adapters need lower ISA clock to work stably).

I don't know why the memory bandwidth is so low, even if I have set every options about RAM and Cache to fastest, but there're not timing options such as CAS or chips speed.

Any tweaking hints ?