Path: utzoo!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!sjsca4!poffen
From: poffen@sj.ate.slb.com (Russ Poffenberger)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: 720k Drives on AT
Keywords: 720k drives AT
Message-ID: <1991Mar8.205710.4320@sj.ate.slb.com>
Date: 8 Mar 91 20:57:10 GMT
References: <1991Mar5.204203.16929@sbcs.sunysb.edu>
Reply-To: poffen@SunOS (Russ Poffenberger)
Distribution: usa
Organization: Schlumberger Technologies, ATE division, San Jose, Ca.
Lines: 28

In article <1991Mar5.204203.16929@sbcs.sunysb.edu> dhoelzer@csserv2.ic.sunysb.edu (David S Hoelzer) writes:
>
>	I've been having a spot of trouble lately.  I have recently come 
>to possess a 3.5" 720k drive.  I installed it in my AT with a modicum of 
>trouble.  It works fine, except for one thing..
>
>	If I insert a disk and take a directory, no problem.  I then eject
>this disk and insert another.  I attempt to take a directory and lo, it
>displays the directory of the disk that I have just ejected!  If any action is
>taken to write to the disk, kiss that baby good bye..  It seems to store an
>image of the FAT and the directory and never refreshes it unless you force it
>to re-read it.. Something like a chkdsk will do it..
>
>	I have spoken to a few people about this.  Half experience the same
>problem, dont know why, and have learned to live with it.  The other half
>have never had a problem...  Let me add that I have had other drives installed
>in this very machine with no problems.  I'd appreciate any info on the problem.

This should be (maybe it is?) in the FAQ list. This happens because the drive
change line isn't being sensed. It could be just a jumper on the drive to
enable it, or could be a bad cable, or a floppy controller that doesn't
support it. On AT class machines, various floppy information is cached for
speed. It may not re-read the drive unless it got the change signal.

Russ Poffenberger               DOMAIN: poffen@sj.ate.slb.com
Schlumberger Technologies       UUCP:   {uunet,decwrl,amdahl}!sjsca4!poffen
1601 Technology Drive		CIS:	72401,276
San Jose, Ca. 95110             (408)437-5254