Mac OS 10.3.9 can't read new Fantom Drive external disc.

Question

I have a Fantom Drive with Firewire & USB 2.0 capabilities. I use it to back up my MacBook Pro (OS 10.5.8). My MacBook Pro reads the drive without any problem when I hook them up. My wife’s MacBook (OS 10.5.2) also reads it. The problem I have is with my older PowerBook G4 (OS 10.3.9) — it can't read ("mount") the drive. When I connect the PowerBook G4 with the drive I get the following message: “You have inserted a disk containing no volumes that Mac OS X can read. To continue with the disk inserted, click ignore.” I click “ignore” and nothing happens. The other two options are “initialize” and “eject.” Obviously, I don’t want to initialize the disk because that would erase the contents. The Fantom Drive is supposedly compatible with Mac OS 10.2.x and higher.
When I queried Fantom Drives tech support I received this reply:
The drive is working fine. Your OS on the 10.3 machine simply cannot read the file system on the drive. Most likely you’re using a file system that is supported on 10.5.x, but not 10.3.x. Apple or Apple enthusiasts may have some software that would enable you to circumvent this limitation, but we cannot offer any guidance here.
Are there any "Apple enthusiasts" out there who can advise me on this?

Answer 1

You would have to do a little research to see if reformatting the
external drive with the older OS X's disk utility could provide a
format scheme that both the newer Intel-based Mac & its kind
of format, as well as the older PPC Mac which uses a diffferent
kind; could both use. Actually, depending on use, the partition
mapping may be the root of the problem. Or something else.
Or if the drive is used only for storage and not sharing between
the computers, some users would use a mapping scheme that
would not allow an otherwise bootable external drive (such as
some use with a clone and a boot copy of the OS X) feature to
exist in that drive.
Depending on the purpose and intent of both computer types
with the external drive, there are variable choices in format.
Even a Fat-32 windows format can support storage; just like
a USB Flash drive ships with by default.
So, when you decide what format and future use the new
drive may see between those two computers, then choose
to reformat the drive so either one or both can use it. But,
if the external drive does support bootable OS X clones,
and you decide to use it that way, the new Intel Mac needs
a different mapping scheme than the older. GUID for new,
APM for the old; and HFS+ formatting for Mac OS, default.
Of course, I would do further research into this matter and
decide what future use the device may have, and with what
computer (and how.)
The older G4 Macs generally can't boot from a USB drive,
and so they'd prefer a FireWire enclosure for their HDD.
The USB speeds are sometimes too slow for best use in
the older Power PC Mac. That is a matter of consideration.
If the Mac uses USB1.1 data storage could be slow if an
external drive was used to save large files to, & retrieve.
The external, if the Apple Partition Map were used, and
the drive reformatted to HFS+ this could be used for
both kinds of Mac computer for storage. Since the drive
is in a USB enclosure, it can't be used for PPC booting
even though that format (APM) supports it otherwise.
Sometimes, an older disk utility may not give the same
options in disk tool availability than a newer one; so
when choosing to change the external drive's format &
other schemes, check into what the newest OS X's
Disk Utility offers; the older 10.3.9 one may be OK for
the basic APM kind of partition map & reformat HFS+
for storage uses. System booting for Intel-Macs in
USB2.0 may be possible; booting Macs in FireWire
may be problematic if the chipset does not support it.
And a self-powered external hard drive enclosure with
its own AC Adapter is better for use with boot volumes.
{Generally, Disk Utility in Mac OS X can do the main job.}
Good luck & happy computing!
PS: while there may be a way to partition free space in a
drive, without erasing content, the partition mapping may
be something so root-level as to not be possible to change
it without losing the existing content on that drive, to do it.
{ edited 2x }