After reconnecting the HD, and powering on, the BIOS indicates that there are no hard drives installed - only the CD-Rom. Using a Windows CD, the Recovery console tells me that 'Setup did not find any hard disk drives installed on your computer.'
Of course, this is the reason why I wanted to use the USB caddy in the first place.
So I can't use Ubuntu (unless I hear differently from this forum), I can't use a Windows CD, and I seem unable to get anything from the USB caddy.
I'd REALLY like to get the files off the old drive before I put a new one in the chassis.
Took R Proffitt's suggestion regarding my USB caddy device (I could not access the drive with any of the jumper settings I tried), and put the HD back in the case, and booted using an Ubuntu CD.
It takes me to a screen where the options are:
Try Ubuntu without any change to your computer
Check CD for defects
Boot from first hard drive
Booting from the 1st HD fails (of course), and when I select 'Try Ubuntu..', it takes me to a creen with the Ubuntu logo and an orange slider installer, followed by a black screen that reads 'Loading, please wait...'
BusyBox v1.10.2 (Ubuntu 1:1.10.2-1ubuntu6) built-in shell (ash)
Enter 'help' for a list of built-in commands.
I have no idea how to proceed, and the link to the storage forum sticky has almost zero information on using Ubuntu to recover files from a HD.