Reminds me a bit about installing one of my 128MB 72 pin SIMM modules in a 486, it has the same caching issues. Most board will not accept them anyway (I have both FP and Edo ones) but if you put a lower capacity one in the first slot they will happily boot and accept the full ram amount if all lanes are occupied (which is not a given on all 486 motherboards). Also remember to enable quick ram check or you will be getting more coffee.