Hi,

I have been a active electronic hobbyist for a while and recently found these IC chips in my grand mother's garage. Apparently the previous owner of the house was an electrical engineer. I am going to school to become an electrical engineer and I am very curious what and how to use these chips. The serial number is P21256-08. I found out they are dynamic RAM but, I am not sure how to wire them and what some of the pins are all for. I looked up the data sheet and found this (https://www.datasheets360.com/part/detail/p21256-08/4924645499488436007/). I was wondering if anyone out there could help me figure out how these chips work and how to use them.

Thanks

 

These are an older technology, NMOS I would bet, and are fairly challenging in terms of generating
the timing to use them. I would avoid using them like the plague.

But if you are dedicated to do so I would think about using a small FPGA or CPLD to get the
timing right.

Regards, Dana.

 

As you found, they're 256Kx1 DRAMs. Only useful if you're going to build a circuit where you need DRAM. Being DRAM, every cell needs to be refreshed "frequently".

I was recently given a hundred or so 64Kx1 DRAMs and, other than testing and selling them, I have no immediate use for them.

 

Hi,

I have been a active electronic hobbyist for a while and recently found these IC chips in my grand mother's garage. Apparently the previous owner of the house was an electrical engineer. I am going to school to become an electrical engineer and I am very curious what and how to use these chips. The serial number is P21256-08. I found out they are dynamic RAM but, I am not sure how to wire them and what some of the pins are all for. I looked up the data sheet and found this (https://www.datasheets360.com/part/detail/p21256-08/4924645499488436007/). I was wondering if anyone out there could help me figure out how these chips work and how to use them.

Thanks

These single-bit DRAMs were commonly used in PCs: 30-pin or 72-pin SIMM - single inline memory module (check this presentation)

Take a look at this reference to have an idea on how the row/column addressing is made in one-bit dynamic RAMs - it shows examples on how to interconnect the memories to comprise a useful datapath (8 bits, 16 bits, etc.).