Re: Modify a Mac external HD for a IIgs?

[dempson@actrix.gen.nz (David Empson)]

<dcaddy@kearney.net> wrote:

> Calling all IIgs experts,
> 
> I have a couple of small Mac external HDs (20 meg & 50 meg) which are
> SCSI ('course). Is it possible to get a SCSI card for a IIgs and is
> there a way to format the HDs to ProDOS format for use with the
> IIgs?

Definitely.  The main candidates are the RamFast (still being sold) and
the Apple High-speed SCSI card.  There is also the older Apple SCSI
card, which is slower and less compatible.

There are also some other third-party which I would not recommend.

The RamFast has built-in firwmare for partitioning hard drives.

With Apple's cards you need to run a separate utility program (under
ProDOS-8).  A really awful one is supplied with the card, but there is a
nicer third-party program (Chinook SCSI Utilities) which is now
freeware.

If you are already using the IIgs System Software (GS/OS), and you have
the full set of disks for System 5.0.4 or later, then you can use the
system software to set up the hard drive with either Apple card.

A 20MB drive can be used without partitioning, but if you want to use
the ProDOS file system then you must break a 50MB drive into at least
two partitions.  (ProDOS is limited to 32MB per partition.)

> When I choose the ERASE DISK command on the Mac I see no options for
> formatting to ProDOS as you do with a floppy.

I suspect that PC Exchange doesn't support ProDOS partitions on a hard
drive, only on floppies, or they may have just not provided support for
formatting.

The IIgs uses the same partitioning scheme as the Mac, so you can set up
a disk which has both Mac (HFS) and ProDOS partitions.  IIgs System 6.0
and 6.0.1 can support the HFS file system for every task except booting,
but only for native GS/OS software.  ProDOS-8 is limited to accessing
ProDOS partitions.

> Or is there a cheaper/better option?

Another option is the Focus card sold by Alltech Electronics.  See their
web page at <http://www.allelec.com>.

It is a controller card with a piggyback IDE drive mechanism.  They are
available in a variety of capacities.

I think a SCSI card would be cheaper, assuming you can find a second
hand Apple or RamFast.  A new RamFast is probably still reasonably
expensive.  (I haven't seen prices recently - last time I was paying
attention, which was about 1993, they were in the region of US$120.)

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand