View Full Version : Questions about upgrading CPU/Memory on my IBM PC 330

October 5th, 2013, 06:00 AM
Hey guys,

Once again apologies for the noob questions.

I bought an IBM PC 330 on eBay. Got it for a great price $30. Pretty good nick. Spent a solid 2 hours last night picking the stupid case lock on it, and FINALLY got it open. I noticed that it has a socket-3 CPU adapter. Right now it has a 486DX4 in it and only 12 MB of memory. I want to upgrade the processor and memory.

Looking at the wikipedia page (see link below), it looks like this was the lower-end 330. Am I able to just plug a pentium processor in the socket-3? If so, could anyone tell me what the most powerful pentium processor would be that I can plug in? The wiki says the highest end 330 had a Intel Pentium 54C, 75-166MHZ (up to 233 MHz using the Pentium 233 MMX with 75 MHz settings). Could I use this processor in the board of my base 330? What would I search for on ebay when I am looking for processors?


It says that the memory chips are 72-pin 70NS chips, and that the max on-board memory is 128MB. Does that mean I can ONLY put 70NS 72 pin chips in there? If so, would these work?

http://www.ebay.com/itm/32MB-SIMM-FPM8x32-72PIN-70NS-OR-FA-Vintage-Apple-Memory-2-pcs-64-Total-MG-/321203167756?pt=US_Vintage_Computing_Parts_Accesso ries&hash=item4ac933620c

I would like to max the memory to 128MB. If I can install other chip, which ones would I install?

Thanks for your time.

October 5th, 2013, 07:59 AM
The Pentium 233 MMX is a Socket 7 processor, not a Socket 3.

October 5th, 2013, 12:01 PM
According to the Wiki page you linked to, you probably have the PC 330 Model 6571, the reason being that you said you have the 486 processor. It is capable of supporting a 486 processor running up to 100MHz, the 486 DX4 processor would have you maxxed out at 100MHz. No upgrade path there.

According to the PC 300 Hardware Maintenance Manual (http://ps-2.kev009.com/basil.holloway/boo-to-pdf/S83G_7789_08.pdf) , the model 6571 uses parity or non-parity 70ns industry standard gold plated simms and supports up to 128MB. Verify yours is the model 6571 to use this info, see page 2.22.1 of the HMM to reference other models/memory types. I don't know if you can use a different speed memory, the book says 70ns.

You can go here here (http://sonic840.deviantart.com/art/Computer-hardware-poster-1-7-111402099) to get a picture of the "Computer hardware poster by Sonic" that shows many different CPU and memory socket variations. Just click the download link on the right side of the page. It's a great reference to what fits what.

October 5th, 2013, 01:00 PM
Depends what you want to do with it of course, but 8MB-16MB was in the normal range for a 486 system 'back in the day'. I'd look for a P200 or something like that if that's the system you're after.