Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!zaphod.mps.ohio-state.edu!lavaca.uh.edu!uhnix1!nuchat!steve From: steve@nuchat.UUCP (Steve Nuchia) Newsgroups: comp.unix.i386 Subject: Re: SCSI and 386/ix Message-ID: <19300@nuchat.UUCP> Date: 6 Feb 90 14:55:12 GMT References: <25c1fdd8:490comp.unix.i386@nstar.UUCP> <1990Feb3.191842.1991@ddsw1.MCS.COM> Reply-To: steve@nuchat.UUCP (Steve Nuchia) Organization: Houston Public Access Lines: 19 In article pcg@rupert.cs.aber.ac.uk (Piercarlo Grandi) writes: >This perplexes me. You sure that a WD1003 style controller can >overlap seeks? Are there any that do? I can hardly imagine seeks >not being synchronous to the controller with a WD1003 style >controller, that must issue step pulses to the head. Most high performance drives being sold today buffer the step pulses and optimize the head trajectory, so the controller could in theory diddle with the other drive while waiting for the ready indication. >Are there really any RLL or MFM controllers (the WD1006 is by >your implication) that can step independently the two arms? I've never seen any information on how to make any of them do it. -- Steve Nuchia South Coast Computing Services (713) 964-2462 "If the conjecture `You would rather I had not disturbed you by sending you this.' is correct, you may add it to the list of uncomfortable truths." - Edsgar Dijkstra