Is there any trick to it?

Listing of drives that do or don't work?

Things to do? to avoid?

I attempted a cheap TDK USB drive...and couldn't get it to work.

I tried adjusting some of the USB parameters, but must confess I
had no idea what the hell I was doing. :D

I would think you would need L:fat95 for reading PC formatted floppies, but that's just a guess.

I use a MITSUMI USB Floppy drive with the Peg2. It works fine till yet. I have fat95 installed. When u have problems with USB drives, play around with the device settings (which is massstorage.device, like increasing the buffer size) in PosedionUSB Prefs. I had my 1024MB FlashDisk working like this.

I tested a TEAC floppy drive on peg1 worked without problem to read PC
floppies...

shouldn't be different on pegII.

Whoa, mine's working fine now also...maybe I didn't have
fat95 installed when I first tried it (although I thought I did).

After buying this drive for my Mac, I thought USB floppy drives
where hideously slow and terrible...but it actually works "reasonably"
well on the Pegasos. Cool! :)

I don't think there is a reason why USB floppy drives should be slower than normal floppy drives, considering the transfer rate of a floppy drive is much much lower than the USB bus can afford.

I agree...to rephrase, USB floppy drives work horrible
under OSX. The transfer rates are fine, it's the
time from when the drive is plugged in/disk inserted,
to when the volume is finally mounted and useable. Probably
a shortcomming or bug in my version of OSX, as it works
well enough on the Pegasos/MOS (haven't tried it on my Windows
machine yet).