MMaximus wrote on 2021-05-29, 17:00:
PC@LIVE wrote on 2021-05-28, 20:04:This motherboard for 386DX arrived today.
The card includes in addition to the 40MHz AMD 386DX CPU, four 30PIN SIMs for a total […]
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This motherboard for 386DX arrived today.
The card includes in addition to the 40MHz AMD 386DX CPU, four 30PIN SIMs for a total of 4MB (4X 1MB).
I don't know which manufacturer is, on the board it says TK-82C390A-4N-D11SE, this maybe could be useful, from a search I did the board was very similar to the Gigabyte GA-386UM 33/40.
In the next few days I should remove the 3.6V battery, and do a cleaning of the copper tracks, I hope nothing else needs to be removed.
After cleaning I will put a new battery, spacing it out so that it is no longer in contact with the copper tracks.
After checking the jumper settings, I will try to start it, if I have the AMI BIOS screen on the screen everything should be OK.
Unless you particularly enjoy the challenge, I would plug an external battery pack to the motherboard connector after having snipped the barrel battery, and call it a day
Yes, those old motherboards could alternatively mount an external battery, and on my first 386DX (from 1992) I had it.
In practice I would connect a new battery in place of the one on the motherboard, but instead of soldering it to the board, I would solder two wires to distance it and place it at the top of the case, in this way if it were to leak it would not corrode the tracks.
I have done it in the past with other cards, the alternative you suggest of the external battery, instead requires the setting of the jumpers, theoretically it is simple to do, unfortunately I do not have the manual and therefore I do not know how and what are the jumpers to set.
For tomorrow I should proceed with the removal of the battery and the cleaning of the oxidized (green) parts with white vinegar, hoping that there is no corrosion to the internal tracks, and therefore that the board will return to normal operation.
If after cleaning and starting everything will be ok, I will start the final configuration by adding various cards, in addition to a 1MB VGA I would put an SB16 sound card (or similar) with connectors for connecting old CD-ROMs, I would have LAN cards but they don't have the RJ connector, they only have the one for RG coaxial cable, I don't think there is a way to adapt it (maybe through HUB?)
AMD 286-16 287-10 4MB HD 45MB VGA 256KB
AMD 386DX-40 Intel 387 8MB HD 81MB VGA 256KB
Cyrix 486DLC-40 IIT387-40 8MB VGA 512KB
AMD 5X86-133 16MB VGA VLB CL5428 2MB and many others
AMD K62+ 550 SOYO 5EMA+ and many others
AST Pentium Pro 200 MHz L2 256KB