Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!lll-winken!uunet!visix!amanda From: amanda@visix.com (Amanda Walker) Newsgroups: comp.sys.mac.hardware Subject: Re: SIMMs for IIsi - what do I need? Message-ID: Date: 17 Dec 90 21:20:59 GMT References: <1990Dec15.035554.15172@eng.umd.edu> <111547@convex.convex.com> Organization: Visix Software Inc., Reston, VA Lines: 26 In article <111547@convex.convex.com> woods@convex.com (Darrin Woods) writes: >As to WHY Apple says this.. In this case it is because it is true. >And I can testify that I have had the same results as Apple listed, >as I have tried it. You get ID 01's and 03's. Well, I'm not going to go so far as to dispute your experience, but I must say it's a very good trick, since SIMMs marked for the same speed have no guarantees of actually responding at the same speed (you'd have to do very careful die selection in order to do this, actually). Since a 100ns SIMM may well respond within 80ns, it's hard to see how putting an 80ns SIMM in will make any operational difference. I dunno about a IIsi, but I've run a Mac II with mixed speed SIMMs, and as long as they were all at least as fast as the machine's requirements, they worked just fine. Maybe there's an optical scanner inside the cases of newer Macs that lets the ROM read the markings off of the chips. That's about the only way I can think of to make a difference. Someone what to quote chapter and verse from the Tech Note? My copy is evidently out of date, since all it mentions is the size... -- Amanda Walker amanda@visix.com Visix Software Inc. ...!uunet!visix!amanda -- Remember: this isn't reality. This is Usenet.