Yes, there isn't much information on the net about the IA-1. Most of the info is here. It would be great if it had an IDE, but at least the compact flash is treated as a full IDE device.
Yes, under win98, it shows 2 usb controllers, one for each set of 2 usb ports. All usb ports seem to produce enough power to support anything I have plugged in.
I have win98 installed on a 340mb microdrive - it has no problem reading or writing to it.
I also have external USB storage (a hitachi 3.2gig notebook drive and usb HD case from compgeeks) that works well. It plays MP3s off the drive no problem. However, trying to copy large files to it seems to cause a "write error". No problem doing the same thing on my windows me box to the same hd and case. Copying large files from the USB HD works fine, and even running office 97 from it runs fine.
I also have a logitech iFeel mouse, and the linksys usb adapter plugged in. These with the usb hd all work fully and at the same time.
I have also tried:
sandisk usb compact flash reader
logitech usb web cam pro 3000
It had no problem powering the above usb devices, of course, though, for the latter two, it was pretty slow.
Also, you can overclock the processor and you can replace it without modifications to the board as long as you get a 1.9v processor that doesn't mind getting to hot. A k6-2 333 worked in mine - the IA-1 still saw it as a 266, but by using softfsb, you can change the fsb, but not the multiplier.