Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!rpi!netserv2!deven From: deven@rpi.edu (Deven T. Corzine) Newsgroups: comp.sys.amiga.tech Subject: Re: Disk drive ready signal/drive clicking Message-ID: Date: 12 Apr 90 19:46:32 GMT References: <1732@eklektik.UUCP> <16639@estelle.udel.EDU> <13444@thorin.cs.unc.edu> Organization: Rensselaer Polytechnic Institute, Troy, NY Lines: 32 In-Reply-To: tell@oscar.cs.unc.edu's message of 12 Apr 90 17:14:53 GMT On 12 Apr 90 17:14:53 GMT, tell@oscar.cs.unc.edu (Stephen Tell) said: Stephen> From looking at the hardware and a discussion here long ago, Stephen> I believe its like this: Stephen> The bare drive has a signal that says whether or not a disk Stephen> is in the drive. This signal goes to the little interface Stephen> board between the drive and the DB-23 connector (The Stephen> interface is on the motherboard for internal drives, but a Stephen> seperate board on the 1010.) Whenever this signal goes to Stephen> "disk removed," even for an instant, it sets a latch on the Stephen> board. Stephen> Every so often, the system comes along and polls this latch. Stephen> Then, it steps the drive, which clears the latch. If there's Stephen> no disk in the drive, the latch immediately gets set again. Okay, this makes sense. It would have been nice had they found a somewhat less obstrusive way to do it, or maybe they should have had the ROMs always try to step past track 0 instead of alternating -- it's officially a requirement for a proper Amiga drive that such not cause actual head motion, right? If it would always make a lot of noise on an Amiga, rather than the current clicking, you can bet few such Amiga drives would be sold... Deven -- Deven T. Corzine Internet: deven@rpi.edu, shadow@pawl.rpi.edu Snail: 2151 12th St. Apt. 4, Troy, NY 12180 Phone: (518) 274-0327 Bitnet: deven@rpitsmts, userfxb6@rpitsmts UUCP: uunet!rpi!deven Simple things should be simple and complex things should be possible.