How can I identify old RAM chip sizes?

[johnorun]

Is there a vintage RAM chip identifier site?

I have some old RAM dips that I would like to add to an IBM-AT memory card, but i have no idea how the read the part numbers to determine the size of several different numbered chips, like (NS) NMC3764N-15 and (DEC) D41256-15.
Once I know the memory size of one chip, I should be able to multiply that by 8 to arrive at the memory size of one bank of chips, right?

I Google'd, but only info. on Simms and Dimms stick memory shows up!

Thanks for any info...

*Hey, Thomas, do you want another project to work on? LOL

[smithy]

From memory (ha ha), 41256-15 is a 256kx1bit RAM with 150ns access time. You would typically need 8 (or in some cases 9 for parity) to get 256kB of memory

[johnorun]

Thanks, Smithy!
I also have 18 NMC3764n-15's, so do I just figure that 8 of these make 64K of memory?
Different brands of old RAM seem to use different numbers, but I guess you have to look for the"64 or "256" etc hidden within the part # to figure out the amount of memory for a bank of 8?

I need to know this to help with restoring some old PC's.
I don't want to mix the wrong memory chips while installing them!!!

Cheers!

[CPUShack]

www.datasheetarchive.com is your friend

[johnorun]

[CPUShack]

replace the prefix (like the D) with *