mR_Slug wrote on 2020-05-13, 11:14:

Also a (public domain) picture of the Model 401:

Are Intel Model 401 and iSBC 386 boards can work with normal AT power supply or need a special one?

The ones I have played with work fine with standard PSUs. The additional power connector is for additional 5V. I worked out the pinout for it and modified a PSU with the additional power connector on one of my boards. Then that PSU decided to die on me:-(. Anyway it is not necessary.

The 401 i have not booted, as i don't have the memory card. IIRC the additional set of 3 power connectors on the top right are just connected to the 3 on the top-ish left.

Thank you. I have an Intel SBC386AT25F04 but not boot. I thought it might be not boot because it needs a special PSU, but then there is the problem with the motherboard itself. These motherboards look really good.

It may only take 256K simms, also check the jumper settings for the RAM. The large slots take RAM cards, and you have to configure these via the jumper settings too. Also probably best to try standard RAM setting instead of FPM.

Jumpers:
http://web.archive.org/web/20040827214754/htt … -25/jumpers.htm

Failing that, i guess it is time for a POST code diag card.

mR_Slug wrote on 2020-09-10, 18:35:

It may only take 256K simms, also check the jumper settings for the RAM. The large slots take RAM cards, and you have to configu […]
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It may only take 256K simms, also check the jumper settings for the RAM. The large slots take RAM cards, and you have to configure these via the jumper settings too. Also probably best to try standard RAM setting instead of FPM.

Jumpers:
http://web.archive.org/web/20040827214754/htt … -25/jumpers.htm

Failing that, i guess it is time for a POST code diag card.

Thanks, I have tried to test without memory but with POST code diag card, but the card not powered at all and PSU has turned of itself. This is why I have thought that the borad needs special PSU.

Model 401 motherboard needs more information too. This board relies on at least 2 cards, one to have memory and one for making ISA bus to work since there is no 82C206, or DMA, interrupt ICs, timer
etc.

Have photos of these cards for the model 401 motherboard?

Cheers,

Gona wrote on 2020-09-10, 11:31:

Thank you. I have an Intel SBC386AT25F04 but not boot. I thought it might be not boot because it needs a special PSU, but then there is the problem with the motherboard itself. These motherboards look really good.

Please respond, do you have photos of your board and their cards?

Cheers,

Unfortunately I have no cards for the motherboard.