Greg Easthom wrote in a message to Roy J. Tellason:

RJT>  GE> The typical indication of the wrong type being used is a system
RJT>  GE> giving error beeps and not booting as it cannot use the memory
RJT>  GE> installed. The system will not proceed past POST (Power On Self
RJT>  GE> Test). 2-clock was only used in 66 MHz systems. All PC 100 and PC
RJT>  GE> 133 memory is 4-clock only.

RJT> Which doesn't *quite* say that a 66 MHz system needs the 2-clock 
RJT> variety,  only that it might.  Is there any easy way to tell?

GE> 1 - Read or download a manual (if you can find one anywhere). 2 -
GE> Visit a "Memory" site (unless you don't have Inet access). 3 -
GE> Borrrow someone else's RAM and see what happens.
GE> 4 - Wait for me to find more info "out there".

GE> I tried a 64MB PC66 strip in this old IBM. It only saw 1/4 of it.
GE> That strip was 4-clock. I found out a bit later I needed 2-clock.

That's interesting,  as I had exactly the same experience with one MB here
-- I got a 64M stick and put it in there and it only saw a quarter of it, 
16M.

GE> I now have 2 strips of old 2-clock 32MB in there, and they work 
GE> fine, even though the strips say "Compaq" on them.

Noted,  with interest.

The board I had the problem with now has 4 16s in there and it works fine.

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