What kind of RAM connector is this?

[jh1523]

See picture at the bottom. Double rows of 30 round pins. Is this a precursor of 30-pin SIMM connectors? Could some sort of adapter be made to use regular 30-pin SIMMs? FWIW this is a 286 clone motherboard.

 

[nestor]

Those conectors are for SIPP modules. These modules are in fact SIMMs with a row pin soldered in the contacts.

 

[jh1523]

I see. Hmm, how difficult can it be to solder a row of headers onto a simm, hmmm.

 

[modem7]

Warning: Some of these motherboards can use either DIL ('regular' type RAM chips) or SIMM/SIPP, but not have both fitted. The motherboard manual will indicate whether or not that is the case.

 

[jh1523]

Yes, this particular one can have either/or.
http://artofhacking.com/th99/m/U-Z/30583.htm
or
http://artofhacking.com/th99/m/U-Z/30583.htm

(they look identical to me)

 

[sergey]

I see. Hmm, how difficult can it be to solder a row of headers onto a simm, hmmm.

IMHO you can buy SIMM connectors and insert them into these SIPP sockets.

 

[Stone]

That's a much better idea than soldering.

 

[svetlyo]

Believe me, it is much easier to convert regular SIMMs to SIPPs, than to solder SIMM sockets on a SIPP motherboard. In both cases you have to solder 30 pins per module (in case of installing SIMMs you also have to desolder the SIPPs - so double the work), but have in mind that the MOBOs are much more fragile than the individual SIMM modules. I have done it once by removing the pins from four 256k SIPP modules and soldering them on 1MB SIMM modules - it was easily doable and you won't risk damaging your MOBO.

 

[jh1523]

I ordered some of those. They're cheap, but I had to order 24 of them to avoid Jameco's "handling" charge.

I wonder however if the assembly will be stable - inserting pins made for soldering into socket holes, with a heavy SIMM balanced on top...

 

[woodchips]

Possible problems. I had a 286 board that used SIP memory, but a different pinout to the standard SIMMs, might be worth checking.

 

[jh1523]

I finally received the connectors from Jameco, and they work really well. They're double connectors, so one fits nicely in a double SIPP connector row on the motherboard. Balancing and mechanical stability is not a problem like I had feared. For good measure I added some sticky tape reinforcement though.

And - no problem with the pinout, standard 1M SIMMs work well.

I did have to physically remove the DIP memory chips from the motherboard - even when configuring the switches for using the SIPP memory, the motherboard wouldn't POST if the DIP chips were left in place.