Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site uw-beaver Path: utzoo!watmath!clyde!cbosgd!ulysses!mhuxr!mhuxj!houxm!vax135!cornell!uw-beaver!info-mac From: info-mac@uw-beaver Newsgroups: fa.info-mac Subject: HyperDrive Message-ID: <340@uw-beaver> Date: Thu, 3-Jan-85 00:43:22 EST Article-I.D.: uw-beave.340 Posted: Thu Jan 3 00:43:22 1985 Date-Received: Thu, 3-Jan-85 23:45:02 EST Sender: daemon@uw-beaver Organization: U of Washington Computer Science Lines: 32 From: Paul R. JohnsonI have some more information from General Computer Company on the HyperDrive. When power is off the heads are moved to a landing pad and locked. In that state they are rated good for 40 Gs. When powered on and running they are rated for 5 Gs. G.C.C. used to have the heads go to the landing pads if nothing had happened for some timeout period. They now think this is not necessary and don't retract them during normal operation. They claim to have had no failures from shock or vibration other than the "throw the Mac on the sidewalk" incident I related previously. With regard to maintenance and Applecare: this is still up in the air. They are talking with Apple about the effect of installation of a HyperDrive on Applecare coverage. G.C.C. is also thinking about offering "HyperCare": i.e., Applecare but also covering their own modificatoins. They will get back to me on this when anything is decided. I also enquired further about memory extension. The way it works is that their current 512K extension is done using 64K chips to extend the existing 128K in the Mac. They could "easily" substitute 256K chips. This would give either 1664K, if only the daughter-board chips are replaced, or 2Meg (2048K), if the existing 64K chips are replaced as well. All of this memory can't be used by vanilla Macintosh programs via Memory Manager calls, but any program that wanted to use it directly could do so. ---Paul Johnson, MIT LCS -------