It is unfortunate 4164s dates before CAS before RAS refresh. Not all 41256s supports it either I think. There were even SIMMs with labels indicating that they a

It is unfortunate 4164s dates before CAS before RAS refresh. Not all 41256s supports it either I think. There were even SIMMs with labels indicating that they are for Mac Plus/SE only when Apple had to use Siemens chips that don't support it.