>Date: Sun, 8 Dec 2002 09:52:58 -0800 >From: Clark Martin <[EMAIL PROTECTED]>
>At 1:22 AM -0600 12/8/2002, Jeff Walther wrote: >> The thing that puzzles me is >>that this ROM bears four Atmel 27C512 chips which should add up to >>256 Kbytes of storage. Yet the silk screening on the ROM says "512K >>ROM SIMM". > >512K ROM SIMM could simply refer to the maximum capacity of the SIMM >and in this case 256K or less of actual ROM was needed. Your correct >a 27C512 is 64KBytes so 4 of them are 256KBytes Ah. And that also makes sense after reading Apple's tech note on ROM sizes. The SE/30 and II family have a 256K ROM, but the next generation, IIfx, IIci, IIsi, have a 512K ROM according to that document. If the SIMM has a 512K capacity, that would make it a lot easier to get the IIci ROM onto some PLCC chips and onto that SIMM. Designing a SIMM board and getting it built would cost some money that I don't want to spend--at least not in the next couple of months. Also, thank you for the information on the 6522. Jeff Walther -- 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> The FAQ: <http://macfaq.org/> --> 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 ---------------------------------------------------------------
