Path: utzoo!attcan!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cwjcc!gatech!purdue!decwrl!sun!pitstop!sundc!seismo!uunet!peregrine!elroy!jpl-devvax!grieggs
From: grieggs@jpl-devvax.JPL.NASA.GOV (John T. Grieggs)
Newsgroups: comp.sys.atari.st
Subject: Re: Hard Disk limitations
Message-ID: <3503@jpl-devvax.JPL.NASA.GOV>
Date: 11 Nov 88 20:32:54 GMT
References: <76253@sun.uucp> <3713@druhi.ATT.COM>
Reply-To: grieggs@jpl-devvax.JPL.NASA.GOV (John T. Grieggs)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Lines: 32

In article <3713@druhi.ATT.COM> dlm@druhi.ATT.COM (Dan Moore) writes:
>	GemDos is still limited to 16 Meg partitions.  Several of
 the hard disk systems do allow you to create partitions larger than
 16 Meg as long as the partition is *NOT* used for GemDos (ie. Spectre,
 Minix, OS9, etc.).  Atari has not said anything about increasing the
>16 Meg limit in the newer TOS releases.

The 16 Meg limit is because of a TOS bug.  Ye olde 16 bit INT
truncation problem strikes again...  Rumor has it that this bug
will be fixed in the new TOS, thus allowing for larger partitions.

>	GemDos is also limited to 16 drives, A to P.  (NOTE: The
 original doc said there was a 32 drive limit.)  Drives A and B
 are used for floppies, leaving 14 drives for hard disk partitions. 
 Atari's hard disk software only supports 4 partitions per physical 
 drive giving a 48 Meg limit.  Supra, ICD and BMS all allow up to 14
>partitions per drive, giving a 224 Meg limit.

Um, almost right.  Only 12 are supported within a single physical unit,
due to a space limitation in sector 0.  Only 4 are in legal space, the
other 8 are stuck in where nothing should be, but it doesn't seem to
hurt anything...  Thus, a single physical drive can contain up to 192 Mb
of useful space, and an additional 2 partitions are possible elsewhere
at 16 Mb each.  Total for system is 224, for one unit is 192.

_john (Astra, for this post)

-- 
John T. Grieggs (Telos @ Jet Propulsion Laboratory)
4800 Oak Grove Drive, Pasadena, Ca. 91109 M/S 301-260A    (818) 354-0465
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