"Haroldo Mauro Jr." ha escrito: > I too, want to upgrade my Mac Plus to 4M. I have three sets of 4-1M > SIMMs: they read -70, -7 and -80 after the manufacturer's part > number. I assume -70 and -7 means 70ns; -80 means 80ns. Is that > correct?
That's correct for all modules I've seen. I've been told that not every memory chip reference ends with the speed, but 70-80 ms. is a reasonable speed, so I would bet they are not the exceptions. > You say they should be 150ns or faster. OK. But the > difference between 150 and 70 is big. Would that be too fast? Should > I use the 80ns or the 70ns set? AFAIK, there's no problem. It should work. The Classic service manual, for example, states that you must use 120 ns. or faster memory. My Classic has three different memories: the motherboard chips are 100 ns., the chips soldered in the memory expansion board are 80 ns., and the two 1Mb SIMMs in the slots on the expansion board are 70 ns. And it works just right. Just make sure the SIMMs have eight or nine chips on them. 68k compact Macs and three-chip SIMMs are a bad combination - you'll surely get a lot of random freezes and system errors. The reason is simple: three-chip modules use a newer addressing schema that is not fully compatible with the old one; the Mac get confused by this, it sends incorrect signals to the memory modules and memory gets corrupted, to tell it in short. Greetings, Antonio Rodr�guez (Grijan) <ftp://grijan.cjb.net:21000/> -- Compact Macs is sponsored by <http://lowendmac.com/>. Support Low End Mac <http://lowendmac.com/lists/support.html> Compact Macs list info: <http://lowendmac.com/lists/compact.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/compact.macs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
