Re: Disk drive ready signal/drive clicking

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#3309

From: Michael van Elst
Date: Thu, 12 Apr 1990 23:20

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In article <DEVEN.90Apr12055052@netserv2.rpi.edu> deven@rpi.edu (Deven T. Corzine) writes:
>danbabcock> The drives are supposed to latch the disk change signal
>danbabcock> when the drive steps a track, so the Amiga steps the drive
>danbabcock> periodically to determine when a disk is changed.
>Now what confuses me is this:  WHY is stepping a track a requirement
>to update the signal??

The drives will SET its diskchange signal just when the disk is ejected.
You have to poll the drive to know the state.
It will RESET the diskchange if a disk is inserted AND the heads are stepped.
This is done to tell the drive that the diskchange state has been
detected. You need this, if you poll the drive in long intervals, otherwise
you'd miss a diskchange.

The drives have ususally a separate line for the acknoledge signal. But
the Amiga hasn't, so the stepping signal is used for that.

-- 
Michael van Elst
p554mve@mpirbn.mpifr-bonn.mpg.de

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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!mcsun!unido!mpirbn!p554mve
From: p554mve@mpirbn.UUCP (Michael van Elst)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Disk drive ready signal/drive clicking
Message-ID: <897@mpirbn.UUCP>
Date: 12 Apr 90 23:20:10 GMT
References: <1732@eklektik.UUCP> <DEVEN.90Apr12055052@netserv2.rpi.edu>
Reply-To: p554mve@mpirbn.UUCP (Michael van Elst)
Organization: Max-Planck-Institut fuer Radioastronomie, Bonn
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