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From: apratt@atari.UUcp (Allan Pratt)
Newsgroups: comp.sys.atari.st
Subject: Re: Hard disk questions
Message-ID: <501@atari.UUcp>
Date: Mon, 29-Dec-86 13:40:53 EST
Article-I.D.: atari.501
Posted: Mon Dec 29 13:40:53 1986
Date-Received: Tue, 30-Dec-86 18:36:53 EST
References: <1894@alvin.mcnc.UUCP>
Organization: Atari Corp., Sunnyvale CA
Lines: 66

> 1)  What is the '40 folder limit' that's been bandied about
>     on the net?  Can one not have more than 40 folders on the
>     disk (this does not make sense), or is one limited to
>     visiting 40 folders in a session?   Do multiple openings
>     of a folder count towards the total more than once?

I have written at length about the 40-folder limit.  To summarize,
	IT IS DANGEROUS TO KEEP MORE THAN 40 FOLDERS ON YOUR HARD
	DISK AT ANY TIME, ACROSS ALL LOGICAL DEVICES.  YOU MIGHT
	GET AWAY WITH IT FOR SHORT PERIODS, BUT IT IS LIKE A LOADED
	GUN: JUST POINT AND CLICK.

> 	2)  Is there a limit on the number of files one can have in
> 	    a folder, or on a logical disk?   Please comment on any
> 	    and all limits..

The root directory of each logical device of your hard disk can hold
256 entries.  Subdirectories (folders) can hold any number of entries.
The desktop can only display a limited number of items in all its windows
(I forget this limit, but it might be around 256).

> 	3)  Should the head parking program (I presume that's what
> 	    SHIP.PRG does) be run each time the drive is powered down),
> 	    or only if it is to be moved?  Is it Ok to turn the drive
> 	    off without special attention?  

The SHIP program does indeed park the head, and should only be used when
the drive is going to be moved.  This is because the parking area might
be dirtier than the rest of the platter, so it's a tradeoff between a dirty
landing zone and possibly crashing on good data.  It is okay to power down
the drive without special attention, but the recommended power up/down 
sequence has the ST last on/first off.  Finally, the drive's controller 
needs a reset from the computer after it's powered up, so don't cycle
power on the drive unless you're willing to reset your computer.

> 	4)  Is the use of nonstandard partitions Ok?  I made up a
> 	    partition by creating an entry in the WINCAP file, and it
> 	    looks fine so far.  Specifically, I have 30 Mb divided up
> 	    into 5-10-10-5.

Nonstandard partitioning is fine.  It sounds like you got parts of the
hard-disk driver/installer from somebody else, and this is dangerous,
especially when you're working with a non-Atari hard disk.  The Atari
hard-disk partitioning program has a number of preset partitions which
you can pick off a menu, or you can set up your own partition sizes
from a partition-editor dialog.  No single device can be more than 16 Meg.

> 	What are some benchmarks I may use to evaluate the
> 'performance' of the drive?  I'd like to run something that's been
> done on the Supra and Atari drives, to make a realistic comparison.

I don't know.  Reading the entire disk sequentially and in a random order (same
random order for both manufacturers, of course) comes to mind.

Thank you, Ravi, for describing your home-brewed hard disk so completely.
I know you realize this, but maybe everybody else doesn't: non-Atari hard
disks like this one can't be supported by Atari Corp.  That means don't call
us with your problems, and you're on your own as far as formatters,
partitioners, and drivers are concerned.  The driver is a critical part
of the Atari product, and it probably won't work with a non-Atari drive.
Even if it does, it is PROPRIETARY SOFTWARE, and should be treated accordingly.

/----------------------------------------------\
| Opinions expressed above do not necessarily  |  -- Allan Pratt, Atari Corp.
| reflect those of Atari Corp. or anyone else. |     ...lll-lcc!atari!apratt
\----------------------------------------------/