Hi everyone. I'm hoping to sell an old computer accelerator card on Ebay in the next few days. The card has a stick of RAM in it but I can't remember what size, so I've looked up the datasheets for the RAM ICs fitted on the stick with the intension of adding up how much RAM is fitted. I'm a little confused with the results I've obtained so I wonder if someone with more knowledge in this area can clear up my misunderstandings.

There are two different RAM ICs fitted to the stick. They are as follows:

16 of KM44C4100J8 (click for online spec sheet)
8 of m5m44100bj (click for online spec sheet)

Now, here is where my confusion starts. Both of the RAM ICs appear to have similar specs with regard to memory size but I'm unclear as to what this is. The spec sheet describes them as follows:

Number of Words: 4M
Bits Per Word: 1

The conclusion I immediately jumped to was that these were 4MB RAM ICs because of the 4M in the spec sheet, but now I'm wondering if that assumption was wrong. The sheet goes on to quote the number of bits per word as being 1. I assume they're suggesting 1-bit Words which sounds very strange to me indeed!!!
If we do assume 1-bit words though, and there are 4M of them per IC, then I guess that would make them 0.5MB chips.

Can anyone clear this issue up?

If I take this a little further as well, I'm assuming that once I've determined the memory size of the RAM ICs I can simply count the number populated on the board and add up to give the total RAM. I'm not sure if it's quite that simple though

Thanks guys

Brian

 

Sounds like 4Mbit memory. Which means 512Kbytes sounds about on par for an old accelerator card.

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