[comp.sys.mac] How much space is in an SE's internal 20 Meg SCSI?

pc@faron.UUCP (Penny Chase) (06/08/87)

I initialized my SE's internal 20 Meg SCSI drive with HD SC Setup
version 1.3.  Everything was successful, but I noticed that my
disk had 19,171K available while other SE's I have seen have
19,868K.  I called my dealer and they said that the amount of space
on my disk was normal and that the reason I have seen the other figure
is that there are two types of drive.  Is this true or am I being
cheated of storage space?  If true, why is there such a difference
(do some drives have less physical space, or do they have the same 
amount of space and are configured differently?)

Thanks for any enlightenment. . .
-- 

Penny Chase

UUCP: ... linus!faron!pc   ARPA: pc%faron@mitre-bedford.arpa

pc@faron.UUCP (Penny Chase) (06/09/87)

Well, I have a partial answer to my own question.  I got hold of a 
copy of version 1.1 HD SC Setup, initialized my disk, and ended up with
19,866K of available space.  So the different amounts of formatted space on
the SCSI disk (~19,170K for version 1.3 vs. ~19,860K for version 1.1)
result from using different versions of HD SC Setup.  Now my question is
what are these versions of Setup doing differently? Were there problems
with the way earlier versions of Setup formatted the disk?  If not, why
change things (after all, if I had a lot of stuff on my disk I probably
wouldn't reinitialize my disk each time Apple changes the system software,
although I would certainly update the drivers)?

-- 

Penny Chase

UUCP: ... linus!faron!pc   ARPA: pc%faron@mitre-bedford.arpa

dgold@apple.UUCP (06/10/87)

In article <150@faron.UUCP> pc@faron.UUCP (Penny Chase) writes:
>Well, I have a partial answer to my own question.  I got hold of a 
>copy of version 1.1 HD SC Setup, initialized my disk, and ended up with
>19,866K of available space.  So the different amounts of formatted space on
>the SCSI disk (~19,170K for version 1.3 vs. ~19,860K for version 1.1)
>result from using different versions of HD SC Setup.  Now my question is
>what are these versions of Setup doing differently?...

I believe this change was made so that all disks of a given size class (i.e.,
20MB, 40MB, or 80MB) would be initialized to exactly the same amount of
space.  This is so the image backup feature of our cartridge tape drive
could be used to restore to a different disk.  The idea is, that if you
backed up your disk, then it got lunched and replaced, then you tried to
restore your backup, the restore wouldn't work if the new disk was from a
different vendor and so had a slightly different amount of free space.
-- 
David Goldsmith
Apple Computer, Inc.
MacApp Group

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