Ok If I buy a new socket 423 motherboard and it comes with two CRIMM's can I just buy 1 stick of RDRAM and put one of those CRIMM's in , instead of another stick??
RDRAM is designed to work in pairs. If you want 256MB then you have to get 2 sticks of 128MB RAMBUS. The CRIMMS are used as electronic placeholders for the empty slots on the motherboard. Usually you have 4 slots available. Since RAMBUS is expensive, they probably figure you can only afford one set of memory and expand later.
i belive that old rambus is 16 bit like old simms and must be installed in pairs to make it work with 32bit processors so you need to install it into pairs the crimms are there just to make the circuit up.