Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rochester!pt.cs.cmu.edu!cad.cs.cmu.edu!ralf From: ralf@cad.cs.cmu.edu (Ralf Brown) Newsgroups: comp.sys.ibm.pc Subject: Re: Adding 360K drive to AT clone: Help needed Message-ID: <1038@cad.cs.cmu.edu> Date: Mon, 12-Jan-87 14:58:08 EST Article-I.D.: cad.1038 Posted: Mon Jan 12 14:58:08 1987 Date-Received: Mon, 12-Jan-87 22:52:15 EST References: <1037@cad.cs.cmu.edu> <2543@ecsvax.UUCP> Distribution: na Organization: Carnegie-Mellon University, CS/RI Lines: 29 In article <2543@ecsvax.UUCP> mjg@ecsvax.UUCP (Michael Gingell) writes: >In article <1037@cad.cs.cmu.edu>, I write: >> I have recently purchased an AT clone (see my previous post for a >> rave review) and am trying to add a second disk drive. I have >> two TEAC 55B drives from my previous computer, but neither of them >> will work in the AT, either as drive A or drive B. The drive which > >The AT uses 2 additional lines to the floppy drives to support the >special HD 1.2 Meg drives... >... Pin 34 is an output from each drive which tells >the AT when a disk has been changed. > >Pin 34 is the culprit. Most pre-AT 360K floppy drives have this >connected as an alternate drive 3 select. If you plug such an unmodified >drive into an AT it will hang. You must either cut the wire to pin 34 >in the ribbon cable, or do what I did, that is cut the trace to pin 34 > >Mike Gingell ....decvax!mcnc!ecsvax!mjg Thanks, Mike! Disabling pin 34 did the trick. +=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=+ | ARPA: RALF@B.GP.CS.CMU.EDU "Teaching COBOL ought to be | | AT&T: (412) 268-3053 (school) regarded as a criminal act" | | Snail: Ralf Brown --- Edsger Dijkstra | | Computer Science Department | | Carnegie-Mellon University DISCLAIMER? Who ever said I claimed | | Pittsburgh, PA 15213 anything? | +=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=+