Date   : Mon, 23 Dec 1985 17:31:35 GMT
From   : Alex Pensky <aep%abic.uucp@BRL.ARPA>
Subject: Re: disk errors [!PLEH] (BDOS err on a:)

> [BDOS err on a: bad sector]
> I see that message way too often. ...

Could be that CP/M is still using the directory and disk parameters from
a disk previously in the same drive, for which the current disk access
would have been erroneous.  The solution is to warm boot (control C)
after every disk change.  If you are running purchased software which
requires disk changes but doesn't reread the directory after you do so,
the software is buggy.

Sorry if this seems like trivial help, but you didn't say what causes
you had already ruled out before suspecting your diskettes.
 
 - Alex Pensky