yawetaG wrote:

I was just guessing, TBH. The only other place I've seen the kind of connector that's above the memory slots is on certain Japanese systems where the motherboard is basically build out of modules that can be swapped for different configurations.

I was talking about the square PGA142 socket, not the NuBus-like slot connector.

What would be the use for a co-processor on a system that already uses a DX processor?

The Weitek works in a completely different manner from the internal FPU; there were some programs optimized for the Weitek that didn't run so well on the regular FPU. Yes it's an oddity but not absurd.

In the mean time I have found 4 cards with the same connector. I assume its some kind of bus and a cable interconnects them all.

^--96-pin DIN-41612/IEC-60603-2 connector. They're used as a backplane connector for tons of different applications, both industrial and automotive. But one of your cards looks to be a 64-pin and won't fit. They usually plug in directly for non-seismic applications, or in a VME type slot for retention in seismic qualified applications. Rarely do they use a cable connection with a riser from all the ones I have at work.

Got some good cards today for basically nothing, now I just need to finish building a test platform to start testing the cards I've been getting.

From top left clockwise:
ATi Mach64 ISA
Reveal 23-023-007
M-Audio Delta 410 (no breakout cable 😢 )
Orchid Technology ProDesigner II
Diamond Stealth III S500 32MB PCI

Picked this lot up today mostly for the 286-12 in the bottom right corner. The Gateway on the very left, though, is loaded up with full and half height SCSI drives and a three internal connector SCSI controller. All the Gateways are P-II models I believe at a quick glance. Some are basic P4 systems. Other than the 286-12 the rest I have no use for so I might part these out. Plan on cleaning up the 286-12 which is in excellent shape.

The 286-12 is B-E-A-Utiful

bjwil1991 wrote:

The 286-12 is B-E-A-Utiful

Yes and a very smart individual cut the barrel out and replaced with a wired battery so no leakage thank goodness, but I still need to test the beast next week. Let's hope it works without much fuss.

I have 2 questions related to my latest lot and dont like to open a new topic:
1) For the IBM PC board, this variable cap is destroyed:

What replacement do I have to buy? Or can I shorten it or install a fixed value cap for testing purposes? If yes, which one?

2) This 286 board is not running:

In the 20 kg box I have found some single ICs. One of them is a "PAL16R4ACN-8735". My assumption is that it belongs on this board, below th ISA slot. The empty socket there is matching and a very similar PAL is already installed (other circle). Does somebody have a similar board and can verify?

Thank you!!!!

liqmat wrote:

bjwil1991 wrote:

The 286-12 is B-E-A-Utiful

Yes and a very smart individual cut the barrel out and replaced with a wired battery so no leakage thank goodness, but I still need to test the beast next week. Let's hope it works without much fuss.

Looks very cool! Can you please post some better pictures, also of the inside?

Predator99 wrote:

I have 2 questions related to my latest lot and dont like to open a new topic: 1) For the IBM PC board, this variable cap is des […]
Show full quote

I have 2 questions related to my latest lot and dont like to open a new topic:
1) For the IBM PC board, this variable cap is destroyed:

IMG_9883r.jpg

What replacement do I have to buy? Or can I shorten it or install a fixed value cap for testing purposes? If yes, which one?

That is the oscillator trimmer according to the IBM PC 5150 technical manual http://minuszerodegrees.net/manuals/IBM_5150_ … 22507_APR84.pdf
It's an adjustable capacitor of 5-30pF and is used to fine tune the system clock frequency. The system will probably run with a fixed capacitor in place (try something like 15 or 20pF) but the clock frequency may be a little nonstandard with that. Best to replace it with a similar value adjustable capacitor and calibrate the clock with a frequency meter or oscilloscope. You can easily find such capacitors on ebay, Mouser etc; if you don't have an oscilloscope, there are basic frequency counters on (again) ebay, Amazon etc for under $20. Here's an example which is identical to one I have and use for similar purposes https://www.amazon.com/0-1MHz-Signal-Frequenc … equency+counter

^^
Thanks for that link!!! I put a 10 pf through the holes but still nothing on the POST card. There must be something elso but I hope these docs will help...

You're welcome. You should start by figuring out if the oscillator is working at all e.g. see if there is a CLK signal at the ISA slots (test between pin B20 and ground http://www.hardwarebook.info/ISA#Pinout)

Indeed, there is nothing. Compared with a working 12 MHz 286. Was not sure if my Multlimeter can handle these frequencies, but on the 286 it shows 7.9 with Turbo and 11.6 without (quite overclocked therefore).

Then I need to exchange the crystal. Will check if I have a spare...I assume the resistor is not neccessary first?

Bought two boards today.

First one is this ASUS P4C800-E Deluxe. It was in a pretty sorry state as opposed to what you see in here. NB heatsink was nearly smashed and the respective retention clips were damaged. Thankfully I had some scrap 865G board so I took care of that. Next up was bulging caps which I fixed too.

Note that the CPU and HSF (along with the retention bracket as well) weren't part of the board when I bought it. I had the CPU from a Intel Desktop Board (D865PERL) and the HSF+retention bracket came from one of my P4P800 boards (865PE as well)

Up next is this MSI P965 Platinum. This came bundled with a Pentium D 925 Presler and the HSF in that picture. This one also had 3 bad caps and didn't POST when I first tested it ( the P4C800 did POST with the bulging caps before recap) but after replacing the three bad buggers, it came back to life.

Predator99 wrote:

Then I need to exchange the crystal. Will check if I have a spare...I assume the resistor is not neccessary first?

I would suggest to start a new/separate thread to discuss those question more in depth.

Predator99 wrote:

Looks very cool! Can you please post some better pictures, also of the inside?

Will do this week as I clean it. That was the seller's photo I used.

Todays flea market finds.

liqmat wrote:

Picked this lot up today mostly for the 286-12 in the bottom right corner. The Gateway on the very left, though, is loaded up with full and half height SCSI drives and a three internal connector SCSI controller. All the Gateways are P-II models I believe at a quick glance. Some are basic P4 systems. Other than the 286-12 the rest I have no use for so I might part these out. Plan on cleaning up the 286-12 which is in excellent shape.

computerlot.jpeg

You can never escape from those P4 Dell Dimensions.

I also had some luck on the flea market today (for just under 20 €).

dickkickem wrote:

You can never escape from those P4 Dell Dimensions.

Wait until 20 years from now people will pay $5000 for these "collectibles"