Re: SCSI Hard Disk Limitations

["Phil Abel" <phil_abel@removethisfornospam.prodigy.net>]

Yes, this has happened to me.  I have hooked up a 2GB SCSI (seagate
barracuda st32550n) drive to my IIgs and I just put down a big HFS partition
on it (using it as a backup/archive drive).  Basically it allocates file
space rounded to the nearest 32k.  So if I save a bunch of 1k text files to
disk, they all take up 32k each-- or at least that is what Finder says when
I browse the folders.  The drive is so big that the wasted space really
isn't a problem, but obviously it is annoying to not know the "true" size of
a file when you look at them in the Finder.  If I copy these files back to a
ProDOS or smaler HFS volume, the file size goes back to normal.

The post references below related to not getting a 2GB SCSI to work may be
other issues-- termination, SCSI ID, DIP settings on drive, etc.

"Bryan Parkoff" <BParkoff@satx.rr.com> wrote in message
qtScnSo4Y5fkGJ2jXTWQlg@News.GigaNews.Com">news:qtScnSo4Y5fkGJ2jXTWQlg@News.GigaNews.Com...
>     Is it true that HFS has a lot of wasting space or clusters if beyond
> 512MB to 2GB?  Curious...
>
> --
> Yours Truly,
>
> Bryan Parkoff
> BParkoff@satx.rr.com
> "David Empson" <dempson@actrix.gen.nz> wrote in message
> 1fnemk6.179hiho1sbxaf4N%dempson@actrix.gen.nz">news:1fnemk6.179hiho1sbxaf4N%dempson@actrix.gen.nz...
> > Paul H. Lee <earnhardtfanpl@hotmail.com> wrote:
> >
> > > I have an Apple SCSI Card, REV 'C' installed in my ][gs with a ROM 01
> > > motherboard.  The machine has a ZipGSX and 6 megs of RAM.  What is the
> > > largets SCSI hard disk I can use?  I connected a 250Mb hard disk to
> > > the system, and everything works fine; but when I connected a 2Gig
> > > drive, the system did not even see it.
> >
> > You might be running into a limitation of the firmware in the SCSI card,
> > but it is more likely to be some other kind of compatibility issue with
> > that particular drive, or something like the new drive not supplying
> > termination power while the old drive did.
> >
> > The absolute limit for ProDOS-8 with the original Apple SCSI card is 7
> > partitions of 32 MB each, for a grand total of 224 MB usable space.  A
> > larger drive will work, but extra space will be inaccessible.
> >
> > Under GS/OS, there is a theoretical limit of 63 partitions, and you can
> > have a mixture of HFS and ProDOS partitions.  HFS partitions can be up
> > to 2 GB (though they have rather a lot of wasted space if larger than
> > 512 MB), ProDOS partitions are limited to 32 MB.
> >
> > In principle, a SCSI card should be able to support 48-bit block numbers
> > (128 EB), which is the limit of the SCSI command set.  There may be an
> > implementation limit in the firmware of the Apple II SCSI cards so that
> > they can only handle 32-bit block numbers, which would limit the drive
> > to 2 TB.
> >
> > An artificial limit of 2 GB would mean that it is only using a 22 bit
> > block number, which would be a rather strange limit.  (4 GB or 8 GB
> > seems more likely.)
> >
> > --
> > David Empson
> > dempson@actrix.gen.nz
>
>