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From: lsr@apple.UUCP (Larry Rosenstein)
Newsgroups: net.micro.mac
Subject: Re: Lights in the disk drives
Message-ID: <11142@apple.UUCP>
Date: Fri, 31-Jan-86 19:01:08 EST
Article-I.D.: apple.11142
Posted: Fri Jan 31 19:01:08 1986
Date-Received: Sun, 2-Feb-86 01:11:38 EST
References: <1636@Shasta.ARPA> <348@ccivax.UUCP> <1667@Shasta.ARPA> <45@gumby.UUCP> <425@mmm.UUCP>
Reply-To: lsr@apple.UUCP (Larry Rosenstein)
Distribution: net
Organization: Advanced Development Group, Apple Computer
Lines: 23

In article <425@mmm.UUCP> mrgofor@mmm.UUCP (Michael Ross) writes:
>
>Then how come my Sony disks work? The write-protect mechanism on those
>diskettes doesn't include a hole going through the diskette - there is a 
>small tab that can be moved back and forth, but you can't see through the
>diskette in either mode.
>

In the old disk drives, the red lights do not actiually shine through the
diskettes.  There is a small arm that is pushed down when the disk is write
enabled; this arm blocks an LED.  (There are 2 such mechanisms; the one on
the left detects the state of the write protect tab, and the one on the
right detects whether or not a disk is inserted.)

On the new drives (at least the ones I have seen), this mechanism has been
replaced by a microswitch, which means there are no LEDs at all.

-- 
Larry Rosenstein
Apple Computer

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