"Michele Smith" writes:

Hi. This board originally took pc66, is there 100 or 133 etc that will work
with it? PC66 is hard to find and expensive. Thanks.

The limitation is that the memory controller on the board will only see memory
chips that are up to a certain density. For example, if you have a 256MB RAM
stick, it may have 8x256Mbit, or 4x512Mbit, or 16x128Mbit chips on it. 64Mbits
was a common limitation on older boards, meaning the biggest stick you could
put in there would be 128MB if it was the normal type with two sides and 8
chips on each side. If you put a bigger stick in there, the board would only
see part of it.

As long as you do not get bitten by the memory density, I can think of two
other issues:

- Cacheable RAM area. This only matters on boards with L2 cache external to
the CPU. Since your PII processor has L2 cache on the CPU, it does not have a
realistic cacheable area limit so you can install as much memory as the board
will take. Older TX boards could only cache 64MB of RAM, and the cacheable
range of Super 7 boards was usually limited by the amount of L2 cache
installed on the motherboard. If you installed an operating system that
loaded at the top of memory like Windows, it would possibly be out of the
cacheable area and thus run very slowly, helping to negate the benefits of
having more memory available.

- I have heard anecdotes that using e.g. PC133 memory in a PC66 motherboard
will fail because the refresh interval on the PC66 memory controller is much
longer than that on the PC133 controller. If the RAM was designed with a
shorter refresh interval in mind, the slower refresh interval may allow things
to fall out of RAM. I have not been able to corroborate this personally, but
it may be something to investigate.