The drive enclosures must also be able to handle "big" drives, over 128G. The one drive you have is an 80G, but since it is Cable Select that is probably the problem.
I got both the WDs working. Made sure both were in Master (one already was, one did have a jumper which I removed to set to Master). Then ran these commands in Terminal
diskutil list
to get the disk ID
sudo gpt recover /dev/disk(#)
where (#) was the disk ID
Both drives then mounted.
The old IBM is a different matter. I set jumpers to both "Master 16 heads" and "Master 15 heads" (don't ask me what this means) but none of my machines can even see it. BTW one of the machines is a non-intel G4 mini. Judging by the occasional click I hear, this old drive didn't like being removed and is kaput. I don't know what else to try—any suggestions are welcome. Naturally it is the one containing the last bit of unbacked-up work I did.
Got a new (used, new to me) MacPro box headed here Friday and the weekend to try to get things back up in something resembling how things ran on the G4. There is some legacy software that I am little concerned about, but will load Snow Leopard and with luck it should run under Rosetta.
I have a weird, potential fix for you. When you have exhausted ALL other means... try this. Put the drive in a Ziplock, remove all air from bag... and put it in the freezer. Let it get fairly cold. (The ziplock keeps it from condensing when you take it out.)Then have your computer room as cold as you can get it and pop the drive in the enclosure.This will sometimes "fix" it long enough to get the data off of it.
Some say it doesn't work on newer drives... but I have seen sooo many comments to the contrary.
Did you try putting the IBM into one of the cases that work with the WDs? You didn't bend a pin or anything?
Tried that. Pins look good. I am going to try the freezer trick as soon as a couple of 1 TB drives arrive. I don't have enough free space on any single dive right now to copy the entire 80GB unit if I can get it working.