A few weeks ago I bought some corroded motherboards from someone local that I've bought from before. There was a 386 board, a 486 board and a 286 board. The idea was to get the 486 board up and running, but that one has a keyboard controller problem and I've put it away for now.
In the lot was a 386 DX 40 motherboard with no cache, I can't identify it but I can kind of work out what's what on there. It for some reason uses a DS1287, which wasn't present at all and the socket for it was damaged. It didn't boot and just went through a couple of post codes very slowly, eventually just doing nothing.

I reinstalled a socket for the DS1287 and ordered some DS1287s from a chinese seller - once they arrived, I plugged it all in and now the board boots! Hooray!
I had to resolder some traces for the keyboard and it doesn't seem to work with one of my PS/2 keyboards, but it works with the Cherry keyboard so that's okay.

Except it can't keep BIOS settings, it won't use an external battery when I plug it into what I think is the battery header. These DS1287 modules have date codes of 1990 and 1992, apparently down to 0.2 and 0.6 volts respectively.
Thankfully I have a dremel and there are lots of YouTube videos showing how to cut into the DS1287 to put on a coin cell holder:

My test setup with the upgraded DS1287 fitted:

Now the keyboard, disk controller, mouse, sound, video all work, excellent 😁

Does anyone know what board this is? I'm wondering what the SLC1 socket could be for and what some of the jumper settings are

The socket could be for a 387 Math Co-Processor or FPU. AMD Am386-DX40 is what I see on there, so a good late 386 board. Happy to see older boards work once again and this makes me want to build a 386. Might build a 486 machine soon, but I have no money right now at the moment (unemployment sucks).

Got some random things this past weekend.
ATi mach 64, S3 virge DX, Yamaha A151-A00, ESS Solo-1 (ES1938S)

Motherboards, S7 board boots but no working keyboard. The 286 and 486 boards need to have battery corrosion removed before testing.

Some controllercards, two ISA, two VLB, one ISA SCSI-controller and an PCI-X one.

Some SCSI stuff, 512MB ECC REG Sdram, and lntel overdrive removal kit.
The harddrives seems to be NOS, compaq 9,1GB 10K Ultra wide.

Some RAM and two joysticks. The RAM however goes to an HP RISC server and won't work in a PC. Well, you can't win all the time.

Vegge wrote:

Some RAM and two joysticks.

Some RAM? Wow. That looks like ALL OF THE RAM.
Pity it's not for x86 computers, though.

imi wrote:

hmm? I don't really see anything wrong with it apart from some yellowing, which is normal I guess if it was exposed to the sun.

I wasn't talking about the SC-7.

Broke my own principle, and bought two computers. Until so far, I had limited my collection to what I have actually bought new back in the day, just buying upgrades for them.

IBM IntelliStation M Pro 6219-38G. Pentium 4 2.66GHz, 1GB ECC DDR RAM, Adaptec AIC-7901 Ultra320 SCSI controller. Very tidy looking machine.

IBM Netvista 6578-NDG. Pentium III 866MHz, 256MB 133MHz SDRAM, TNT2

For just 20 euros a piece, I couldn't leave them.

VioletGiraffe wrote:

Thanks! Yep, that battery irks me, it's a miracle it hasn't leaked yet. Reading 1.6 volts across the leads, it's in best case se […]
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GigAHerZ wrote:

The empty socket is for 387 co-processor. Not necessary, but optional.
For ram... Well, in the end, i have just tried out and then added sticker about the size on it. For me it has been quicker than to go through chips datasets and count together, what's the size...

First thing you want to do is to remove that barrel battery and replace it coin cell or other modern solution!

Thanks! Yep, that battery irks me, it's a miracle it hasn't leaked yet. Reading 1.6 volts across the leads, it's in best case seriously discharged,but likely just dead. Not sure yet what I'm going to replace it with as it's a Ni-Cd rechargeable and a somewhat inconvenient voltage to replace with something other than a similar Ni-Cd or Ni-MH. Maybe a small Li-Po.
Odd, I've searched for 80387 to see how it looks and pretty much all the pictures paint a chip with leads around its perimiter, not with an array of legs under the belly.
Did games of the era use floating-point math? I guess 3D ones could have. Would installing a 387 let me run something that a bare 386DX-40 can't?

Well, with the FPU, you can get Quake 1, Grand Theft Auto and some other Pentium level games running on 386, but this is only for feeling the achievement of doing it. You can't play those games as they run maybe 1-4 frames per second. 😜

NiMH are fine, 3V coin-cell li-ion battery is also fine. The accepted voltage range is quite big. (3V coin cell and 4,8V of NiMH and everything in between is fine)

VioletGiraffe wrote:

Did games of the era use floating-point math? I guess 3D ones could have. Would installing a 387 let me run something that a bare 386DX-40 can't?

One example of the game from 386DX era that uses FPU is Falcon 3.0... but then again high precision flight model that requires it is a bit buggy.

Other than that - Excel and other similar applications. Perhaps some graphic software (CAD, maybe DOS 3D Studio - but I'm not 100% sure) as well.

If not for that, then adding some FPU to the board will significantly increase it's value when you want to sell it, and those 4C87DLCs or Cyrix FasMath FPUs can be found for low price from time to time (on ebay they typically sell them for 15-20 USD)...

GigAHerZ wrote:

Well, with the FPU, you can get Quake 1, Grand Theft Auto and some other Pentium level games running on 386, but this is only for feeling the achievement of doing it. You can't play those games as they run maybe 1-4 frames per second. 😜

So more like crawl, not run, I see 😀
I think I may just want to get another system, just a little bit newer, for the later 3D games. Something like P1-100, Pentium Pro, or Pentium MMX. I remember being completely blown away by Quake II the moment I saw it, and it requires Pentium-90 or better.

GigAHerZ wrote:

NiMH are fine, 3V coin-cell li-ion battery is also fine. The accepted voltage range is quite big. (3V coin cell and 4,8V of NiMH and everything in between is fine)

Ordered a 3.6V Ni-MH battery from Aliexpress, almost identical to the original one, but it will take at least a month to get here. I'd be happy to just drop a CR2032 or similar 3.0V lithium cell there, but the original battery is rechargeable, so the motherboard will attempt to charge it which is of course unacceptable for non-rechargeable batteries like the said 3.0V Li cells. So I don't think a direct drop-in replacement is possible. A diode in series with the cell would protect it from reverse (charging) current, but it would eat up another 0.1-0.2 V, not sure if that will result in acceptable voltage level on the motherboard, especially when the cell itself starts getting lower into the 2.8-2.6 V region.

HanJammer wrote:

If not for that, then adding some FPU to the board will significantly increase it's value when you want to sell it, and those 4C87DLCs or Cyrix FasMath FPUs can be found for low price from time to time (on ebay they typically sell them for 15-20 USD)...

Are you saying I can install a 4C87DLC FPU into my 386DX system? Based on the marking, I would think that particular model is for 486 systems. Are they compatible this way?

It is compatible.

I just found that there are ML2032 coin cell batteries, that are physcally identical to CR2032, but are rechargable. Quick search to aliexpress lead to offers at around 3$ a piece. 😉

EDIT: And LIR2032, which is 3.6V rechargable in the physical shape of CR2032!

GigAHerZ wrote:

I just found that there are ML2032 coin cell batteries, that are physcally identical to CR2032, but are rechargable. Quick search to aliexpress lead to offers at around 3$ a piece. 😉

EDIT: And LIR2032, which is 3.6V rechargable in the physical shape of CR2032!

And if there's no circuitry present in the mother board to charge those batteries correctly, you've just obtained yourself a nice way to have a surprise fire via overcharging...

VioletGiraffe wrote:

HanJammer wrote:

If not for that, then adding some FPU to the board will significantly increase it's value when you want to sell it, and those 4C87DLCs or Cyrix FasMath FPUs can be found for low price from time to time (on ebay they typically sell them for 15-20 USD)...

Are you saying I can install a 4C87DLC FPU into my 386DX system? Based on the marking, I would think that particular model is for 486 systems. Are they compatible this way?

They are. I have three motherboards with 386DX40 and IIT 4C87DLC (although I plan on upgrading 2 of them with TX486DLC - I have CPUs, I just havn't done it yet. It's just some kind of marketing strategy they took based on a fact that it supported some instructions from 486 FPUs. Similar to how 287XL was based on 387 FPU...

I'm on a shopping spree today 🤣

Got this Digigram VX222 sound card for 2,5€. If it's not very good, it's not a big loss. I think I'm going to use this on my new Intellistation. Too bad it didn't come with the breakout cables, it only has 3,5mm audio out on board. It is some kind of professional audio card with balanced inputs and outputs. Made in France. It has been very expensive card when new: https://www.studiocare.com/digigram-vx222-hr- … sure-i-o-s.html

edit: Found a cable pinout for this. Seems trivial to make a suitable cable actually.

Vegge wrote:

Some RAM and two joysticks. The RAM however goes to an HP RISC server and won't work in a PC. Well, you can't win all the time.

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I got to ask, did you buy the simms storage box yourself or the ram came in it? I'd like to buy one but I can only find the dimms variant. So in case you know where to get one please share the information!

I LOVE NETVISTAS

they're great looking, sturdy, fantastic.

I like NetVistas as well, in fact I plan to build a modern PC in a NetVista case (it's standard mATX)

I've done that and it's an excellent idea. If you get an SFX PSU you won't even have to modify anything whatsoever.

I wouldn't be able to sleep at night after butchering perfectly good classic computer 🤣