Re: Max usable space on ProDOS hard drive?

["Mark Cummings" <figjams@primus.com.au>]

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In article <3b526eb8.124640207@news.mw.centurytel.net>,
mister_boffo@hotmail.com (Mister Boffo) wrote:
>I have an Apple High-Speed SCSI lying around.
>And an APS 700 meg SCSI drive.
>
>So, can an Apple II really make use of all 700 megs or is
>there some sort of "hard limit" to what it can access?

Apple II no, IIGS yes. The Apple II can only use about 256MB (8x32M) AFAIK
I have a couple of large HDD on my GSs, a Focus 500M on one & Quantum 1.2G
on another.
The Focus 500M came preformatted with 17 x 30M ProDOS partitions which
worked under GS/OS, but I didn't like the way it filled up the desktop with
HDD partition icons. Also slowed down the boot process as it mounted all the
vols on the desktop.
The Quantum 1.2G SCSI drive on my AHS card was ex-Macintosh, so I was left
to choose my own partitioning scheme.
My partitioning would have been 32 x 32M in just ProDOS partitions wasting
200M. Besides that you can only fit about 30 icons on the desktop in System
6.0.1, I'm not sure what happens with any extras.
I would also like to be able to put two HDDs in my GS so file tranfers can
be done at the maximum rate, making it easier to backup or setup a HDD.
Taking this into account and the possibility of using these HDDs on a maxed
out GS I used the following formula to determine a practical limit on the
number of volumes.
 30 Max icons on desktop (AFAIK)
- 1 for Trash
- 2 for dual 3.5 floppy's
- 2 for dual 5.25 drives
- 2 for two 5.25 floppy's in the drives
- 1 for RAM disk
- 1 for CD-ROM
=21 remaining, and possibly take away a few more if you have some appleshare
vols (say 2)
- 2
=19.
divide this by two so you can have 2 HDDs in the GS at the same time
= 9 vols per HDD max.

Using this logic I decided to partition my drive into 7 or 8 x 32M ProDOS
partitions and the rest as one big HFS vol, giving a total of 8 or 9
partitions on the HDD, which works out pretty well for ProDOS 8 too
considering it can only access a max of 8 ProDOS partitions anyway.

I found that most of my applications will easily fit inside the 7 or 8 x 32M
partitions and I was mainly using the rest for disk images or preparation
for archiving anyway, so I was mainly using those when in GS/OS anyway. The
only exception to this is that I use the 2nd partition for 8 bit Shrinkit
images, because it can't see the HFS vol anyway.

I think you can go to about 1.8 - 2.0G max in HDD for the GS.

>I think ProDOS can create up to 32 meg partions. So I guess
>I would need to create 21 32-meg partitions to use 672 megs
>of space, then one partition of 28 megs to get the last bit
>used. Can ProDOS handle 22 disk volumes like this?

not ProDOS, but GS/OS can see the ProDOS vols in System 6.0.1.

>If it can't make use of all the space is it possible for
>ProDOS volumes to coexist with Mac, PC, or other types of
>SCSI partitions?

I havn't had much success here yet, so basically I have gone for Appleshare
as a compromise for fast transfers from Mac HDD to GS HDD. 100Kbps is pretty
good compared to disk shuffling.

Mark