Note: my supplier has raised their prices so unfort I have to raise mine as well.

These are static ram chips that can be used with arcade games and computers that have 16 or 64k ram. To modify them for 16k ram replacement you need to follow these instructions:

Let's have another look at the pinouts of the 2 RAM types:

       ___  ___                ___  ___
 -5v -|1  \/ 16|- Gnd    n/c -|1  \/ 16|- Gnd
 Din -|2     15|- /CAS     D -|2     15|- /CAS
 R/W -|3  4  14|- Dout   /WE -|3  4  14|- Q
/RAS -|4  1  13|- A6    /RAS -|4  1  13|- A6
  A0 -|5  1  12|- A3      A0 -|5  6  12|- A3
  A2 -|6  6  11|- A4      A2 -|6  4  11|- A4
  A1 -|7     10|- A5      A1 -|7     10|- A5
+12v -|8      9|- +5v    Vcc -|8      9|- A7
       --------                --------

If you remember, the only pins we needed to re-route were those on
three "corners", the power supply pins 1, 8 and 9. 

OK, well the data pins are all in the correct places but we'll need 
to do something about the power supply pins which are needed for the 
4116 but not the 4164. Also, the 4164 has 4 times the capacity of the 
4116 so we'll need to address that too. This turns out to be really 
easy, the A7 pin of the 4164 is in the same place as +5v on a 4116, 
so we don't need to do anything here and A7 will be tied high. Pin 8 
of the 4164 (Vcc) will be connected to +12v unless we do something 
about it. We bend the pin so that it won't go into the socket and 
jumper it to +5v - the easiest way to do this is to connect it to 
pin 9 on the other side of the chip. The surplus length of the bent 
pin 8 can be snipped off. Finally, pin 1 of the 4164 should not be 
connected to anything but will be connected to -5v if placed in the 
socket for a 4116. We can simply snip off this pin and all is well.