You are VERY VERY right Andy. I looked at the possibility of implementing a host end of USB a couple of years ago. I was looking at using a 32-bit ColdFire processor running at something like 66 MHz. I came away from that realizing the software effort to properly implement the host end would be on the order of about a man-year of work along with the rather costly purchase of piece of USB IP.

Last year I worked on an embedded system development using a PC hardware platform that ran Win2000. There was a desire to have an ability to boot the system from a CDROM for the purposes of field system upgrades and hard disk crash recovery. I tried to persue the use of a USB port attached CD-ROM drive so that the field engineer could easily connect a drive from his service pack. (IE you see USB CDROMs are ready-made devices). However our product ended up with a removable access plate, under which the field engineer could access a 40-pin IDE ribbon connector and a 4-pin power jack. They ended up being to boot from CDROM albeit a much less elegant implementation. The problem with the USB CDROM was that the ROM BIOS in the PC platform did not support booting from USB, just SCSI and IDE. I contacted two different ROM BIOS vendors to see about getting USB booting capability built into a BIOS. One vendor quoted a $100K implementation fee + $10 additional royality fee per system. The other vendor declined the implementation.

Things may have changed in the last 6 to 8 months but I doubt it. It will in general be very difficult for embeddded systems designers to take advantage of low cost plug-and-play USB peripherals.

It is too bad that this is the case because the PC marketplace dictates the availability of connectivity devices that are widely available and low cost.

Michael Karas