Assuming that our version of the ClamShell iMac has a Firewire ports, and not all of them did, and the drive is plugged into its power connector and actually spinning, there should be no reason why this drive does not appear on the desktop.
I did note that there was a mention of laptops and the need for a 4 wire Firewire connection.
Contact the Acomdata Tech Support for more info.
I have a clamshell Ibook PowerPC G3, 10.3.9, 366 Megaherts, with 192 ram.
I bought this for my computer, but it is not showing up on my desktop. Moreover, it does not appear on Disk Utility, nor the System Profiler. It connects via firewire if that makes much of a difference.
This is the model:
And I followed the support suggestions to no avail.