16kx4 cache 24 pins?

Hello,

I'mtrying to upgrade a DecPC Lpx 433sx by adding cache memory. The manual
says that I have to add 8 modules of 32kx8-20ns and 3 modules of 16kx4. So I
added 11 modules of SRAM, but with acces time of 15 ns, which has to be no
problem. However, it doesn't work. How come? I have some options:
- 15ns doesn't work...
- the 16kx4 is 22 pins, but the dip-socket has 24 pins!! Maybe this is the
problem. But what is the solution? How do I have to place the SRAM or do I
need other ones?

Please help me! Greetings and thanks,
Michiel
(PS for my email: remove the part after my name in front of the @)