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From: c9037544@cc.newcastle.edu.au (David Williams)
Newsgroups: comp.sys.cbm
Subject: Re: @: (save/replace) bug?
Message-ID: <1991Mar20.154750.9862@cc.newcastle.edu.au>
Date: 20 Mar 91 05:47:50 GMT
References: <1991Mar20.095745.9860@cc.newcastle.edu.au> <5701@gara.une.oz.au>
Organization: University of Newcastle, AUSTRALIA
Lines: 27

In article <1991Mar20.095745.9860@cc.newcastle.edu.au>,
c8923075@cc.newcastle.edu.au (Chris (Polar) Baird) writes:
> 
> Could someone please explain what the 'save/replace' bug was on the
> 	original (grey) 1541? How it happens, why it happens, does it
> 	still exist, or does anybody really know?

Commodore's DOS allows a filename to take the form :
   "@[device]:filename" (eg:  save "@0:fred",8)
 The device bit is purely optional and is only there as early drives contained
two units, specified as devices 0 and 1. The @ however, meant for the DOS to
erase any previous file on the disk of this name. The way it worked was for
the new file to be saved, and then the old one erased. This meant that it would
fail if you did not have enough space on your disk for the new version. The
famous 'bug' however, is that often is just did not work. I cannot remember
the details, but I do remember that it could corrupt your disk directory.
This was only with the very old 1541's (I have done this on occasion, and have
certainly never had a problem). The solution is just to erase your old file
first, before saving.

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| David Williams                      | University of Newcastle, Australia    |
| c9037544@cc.newcastle.edu.au        | Computer Science student              |
| c9037544@jupiter.newcastle.edu.au   |                                       |
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