Re: Modify a Mac external HD for a IIgs?

[toh@victoria.tc.ca (Marc Sira)]

In our last episode, dempson@actrix.gen.nz (David Empson) said:
>> PC Exchange (File Exchange in Mac OS 8.x) does support ProDOS filesystems in
>> Inside Mac V partitions; I've used it for years.
>
>In that case, why didn't it offer a ProDOS option (for Darre - the
>original poster) when erasing the disk?  I've seen it for floppies, but
>I've never needed to erase a Mac hard drive partition.

It looks as if some of the ProDOS functionality that was in PC Exchange is now
gone from File Exchange (as of Mac OS 8.6, and probably earlier). I can still
mount a ProDOS partition (there's even a nice modern hard disk icon with a
little multicolored "II" on it), but the "Erase Disk..." dialog no longer has
the option to initialise for ProDOS, and I can't even erase an existing ProDOS
partition (the menu option is undimmed but does nothing when selected, which
is rather bad manners and certainly not to HI spec).

>An obvious possibility, given the size of the drives quoted, is that
>Darre is running an older version of the Mac system software, which
>doesn't have PC Exchange.  (It was definitely there in 7.5.3, but I'm
>not sure about 7.1.)

I believe PC Exchange came along (with ProDOS support) as of 7.5, and was
superseded by File Exchange (with better FAT support, but less ProDOS) in
8.5 (8.1 on certain machines). Offhand I'd say they're phasing out ProDOS
slowly, which is regrettable (but for that matter they're phasing out regular
HFS in favour of HFS Plus, which is a good thing).

7.1 or 8.5 Mac users can still create ProDOS partitions with an appropriate
tool (like an older third-party hard disk program), but it'd probably be
easier to just do it on the IIgs with a RAMFast or GSOS boot disk. It's also
possible to create a ProDOS partition just by sector-editing the partition
table ("Apple_HFS" becomes "Apple_ProDOS" - love that flexible partition
scheme :) but that still leaves the problem of creating a filesystem. 

Finally, one could take the PC Exchange control panel from 8.1, 8.0, or 7.5.3
(which is freely available) and use it to temporarily replace File Exchange
for long enough to "Erase" (initialise) a new ProDOS partition. Should work,
though no guarantees are possible with 8.5 or later.

-- 
Marc Sira		|	toh@victoria.tc.ca
If you can't play with words, what good are they?