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The Capacity Of These RAM Modules For The 500 Series?

Posted by: Paralel on 2013-08-28 13:55:09 Can anyone tell me what the capacity of the RAM modules below are?

Posted by: dougg3 on 2013-08-29 06:50:30 The module on the left uses a Hitachi HM5117400A chip. Well, it's an HM5117400ATS6, which means it's 60 ns and in a TSOP package: http://www.datasheetarchive.com/HM5117400A-datasheet.html Each one of those chips is 4,194,304-word * 4-bit, or in other words 16 megabits or 2 megabytes. There are 16 of them, so it looks like the left module is 32 megabytes. The module on the right uses (I think) a Fujitsu MB8117400, again 60 ns. I'm not 100% sure on this one, but it appears very likely. http://www.datasheetarchive.com/MB8117400A-50%2F-60%2F-70-datasheet.html This one is also 16 megabits (2 megabytes), and again 16 chips, so I think the right module is also 32 megabytes.

Posted by: Paralel on 2013-08-29 07:26:35 Thank you! That's where I was screwing up, I was reading the datasheets as 16 megabytes, I was like "...There is no way that is correct..." Well, looks like I'll have a spare 32 MB card to put up in the trading forum once they arrive. Assuming they both work correctly. Now I just have to figure out which one to keep. I think I'll go with the spectrum eng. one. That one seems more like the design I am familiar with.

Posted by: Paralel on 2013-08-30 11:28:40 Doug, you were right, they are both 32 MB cards. I guess I got lucky, or they're easier to find than people think.

Posted by: dougg3 on 2013-08-30 12:03:06 Thanks for coming back and confirming! I was curious if I was reading the datasheets correctly.

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