> The 5000/1xx series takes MS01-AA (in pairs of 2MB SIMMs) and MS02-BA
> (in pairs of 8MB SIMMs) memory modules.

Come on, Simon - you've been playing with the 200s too much lately.
The RAM modules used by the 5000/1xx and 5000/xx machines are the
        MS01-AA (4MB - pairs of 2MB each)
        MS01-CA (16MB - pairs of 8MB each)

The 5000/2xx machines use the
        MS02-AA or MS02L-AB (8MB)
        MS02-CA (32MB)


What is a VAX 4100?  Do you mean the VAX 4000 Model 100?
This fits in a BA42B enclosure (similar to the DECsystem 5100).
The memory options I'm aware of for the 100A are:
        MS44L-BC        16 MB (4x 4MB modules)
        MS44-DC         64 MB (4x 16MB modules)

If this is the beast you're thinking of, I think you're out of luck.
__
David Burren
davidb@convergent.com.au