Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!apple!dwells From: dwells@Apple.COM (Dave Wells) Newsgroups: comp.sys.mac Subject: Re: Upgrade Memory on SE/030 Summary: Upgrade options for the IIcx and IIci Keywords: IIci, RAM, SIMMs Message-ID: <35221@apple.Apple.COM> Date: 3 Oct 89 18:10:21 GMT References: <12679@orstcs.CS.ORST.EDU> <35202@apple.Apple.COM> <1989Oct3.144854.24428@agate.berkeley.edu> Organization: Apple Computer Inc, Cupertino, CA Lines: 39 In article <1989Oct3.144854.24428@agate.berkeley.edu> bmug@garnet.berkeley.edu (BMUG) writes: >In article <35202@apple.Apple.COM> dwells@Apple.COM (Dave Wells) writes: >>Yes, you can add 4 1MB SIMMs to your SE/30 to get a total of 5MB. Only catch >>is that you'll have to relocate the 256K SIMMs from bank A to bank B and put >>the 1MB SIMMs in bank a. This works like a charm. >> >>This is the same solution as for a Macintosh II, Macintosh IIx, and Macintosh >>IIcx... > >We've heard that the IIci has an arrangement whereby it isn't necessary to >relocate the 1 mb which comes with the machine to the "B" bank when adding >SIMMs for more RAM. Is this true? Is it because new machines are >shipping with the weird new quarter-MB SIMMs? > >Enquiring minds want to know... Yes, it's true. The Macintosh IIci is the first to allow the RAM in bank B to be of higher density than the RAM in bank A. In fact, you can install RAM in bank B and take the SIMMs out of bank A and the Macintosh will work fine. (Minus built-in video, which uses RAM from bank A.) This fantastic new functionality :-) is enabled by the new Memory Decode Unit chip that replaces the old GluChip from previous Macintosh II models. Besides some other things, it removes the RAM configuration restrictions that were present in previous Mac II's. If you're wondering where it is on the logic board, look for the large, square chip, under the SuperDrive, about halfway between the front and the floppy cable socket. The "weird new quarter-MB SIMMs" are just that. Weird, quarter-MB SIMMs. They use a different chip configuration because supplies of the normal chips at 80ns was/is insufficient. -Dave -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Dave Wells, Apple Computer, Inc. MS: 37-O (408) 974-5515 Mail: dwells@apple.com or AppleLink d.wells or GEnie D.WELLS These opinions may be nothing more than the ramblings of a fatigued tinkerer -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-