Path: utzoo!attcan!uunet!ginosko!uakari.primate.wisc.edu!uwm.edu!uwvax!umn-d-ub!umn-cs!bungia!orbit!pnet51!granteri From: granteri@pnet51.orb.mn.org (Grant Erickson) Newsgroups: comp.sys.mac Subject: Re: New SIMMs for the Macintosh IIci??? Message-ID: <1150@orbit.UUCP> Date: 24 Sep 89 23:05:04 GMT Sender: root@orbit.UUCP Organization: People-Net [pnet51], Minneapolis, MN. Lines: 46 jeff@ndcheg.cheg.nd.edu (Jeffrey C. Kantor) writes: >In article <1149@orbit.UUCP>, granteri@pnet51.orb.mn.org (Grant Erickson) writes: >> After a long run down of the Macintosh IIci and the Macintosh Portable and the >> Minnesota Macintosh Users Group meeting, I was enlightend to the fact that in >> the IIci you must use 80 nanosecond F)ull P)age M)ode SIMMs. These must be >> used to take advantage of the burst-mode of the 68030. >> >> [stuff deleted] > >What is a F)ull P)age M)ode SIMM? I know what the 80ns bit is all about, >but what does the FPM bit mean? > >More to the point, if I order 80ns SIMMs from the usual list of SIMM vendors, >will they work in a MacIIci? > > >-- >Jeff Kantor > US Mail: Dept. of Chemical Engineering >internet: jeff@ndcheg.cheg.nd.edu University of Notre Dame > uucp: iuvax!ndmath!ndcheg!jeff Notre Dame, IN 46556 USA Well as Paul Pashibin of Apple Corporate in Bloomington, MN explained it as being this. Lets say you have a data word. The 68030 grabs the first 1/4 in 5 cycles, the 2nd 1/4 in 5 cycles, the 3rd 1/4 in 5 cycles, and the final 1/4 in 5 cycles. This ends up taking 20 cycles consequently. So with the FPM SIMMs together with the 68030's burst mode, it reads 1st: 5 Cycles and the next consecutive 3 in 2 Cycles each. There for you have a total of 11 Cycles compared to 20 giving you a 181% speed increase in that situation. I myslef do not know if people like Chip Merchant will have these at the current low $89 price for NORMAL 80Ns SIMMs. Disclaimer: I have no affiliation with Apple nor Chip Merchant or anyother company that you might want to dream up. Grant Erickson ._________________________________________________________. | UUCP: {rosevax, crash, orator}!orbit!pnet51!granteri | | ARPA: crash!orbit!pnet51!granteri@nosc.mil | | INET: granteri@pnet51.cts.com | |---------------------------------------------------------| | The right half of the brain controls the left half | | of the body. This means that only left-handed people | | are in their right mind. | !_________________________________________________________!