Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!uunet!zephyr.ens.tek.com!gvgpsa!treehouse!andyp
From: andyp@treehouse.UUCP (Andy Peterman)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Minor Hard Disk Question...
Message-ID: <905@treehouse.UUCP>
Date: 27 May 91 17:52:14 GMT
References: <1991May27.081538.9810@marlin.jcu.edu.au>
Organization: The Treehouse
Lines: 31

In article <1991May27.081538.9810@marlin.jcu.edu.au> chma@marlin.jcu.edu.au (Michael Antolovich) writes:
>Hi,
>   Something I noticed recently :-  I reformatted my Quantum 105 (3rd
>party so I fiddled with Apple's formatter :-).  Anyway I was just
>wondering why my 105Meg HD formats to 102Meg (Max partition size) then
>shows ~100,000K fress space when empty under System 6.0.7 and then
>~98Meg under System 7.0 (yes it goes back to 100,000K when I go back to
>6.0.7).  I more or less understand the reduction caused by formatting,
>etc, but why the diff between Sys 7.0 and 6.0.7 ?  It's a pity to 'lose'
>the 7 Megs I could have used to for puting System 7.0 on :-).

The Quantum 105 does indeed contain about 105 million bytes.  However,
since 1K is 1024 bytes, this translates to 102,537.5 K.  Also, since 1
Meg is 1024 K, then you really have a disk that is about 100.1 Meg.

Then there's some overhead on the disk that you never see.  The
partition map and driver takes up about 30 to 70 K.  For each volume,
there's about 10K of information.  Then, there's probably about 1 Meg
each for the volume extents and catalog trees on each volume (these can
grow if you have LOTS of files on the volume).

This leaves you with about 100,400K free as viewed by the 6.0.7 Finder or
with about 98 Megs as viewed by the 7.0 Finder (which shows large values
in Megs).

Hope this helps...

-- 
Andy Peterman                       |   Opinions expressed
treehouse!andyp@gvgpsa.gvg.tek.com  | are definitely those of
(916) 273-4569                      |      my employer!