Thanks, I was afraid that you were going to say that.
I was hoping to be able to take any drive that normally boots on the system maybe with two or three distributions on it and just plug it in and be able to select it from the boot menu without making any changes to it at all.
I thought that I would be able to do this just by modifying the menu.lst.
Linux is so nice compared to Windows in that you can frequently take a drive with a running Linux install and plop it into a different machine and it just works.
I was hoping to be able to swap them between machines on occasion without making any changes.
But, as easy as it is to modify a menu.lst, I guess there really isn't that much value in doing it that way.
But, I still don't understand why it won't work.
Being able to move my hard drives between machines was what prompted me to get the removable bays. I had three computer shells in three cities that I circulated between. One machine had 4 bays, and the others each had three. Whenever I changed cities I just put the caddies in a carry case, then inserted them in the waiting shell, at the new location. That way I always had the same desktops, and same applications, and everything was always in the same relative place. When I stopped moving between cities, I kept the best of the three shells, and never bothered to change anything else. I pulled the bays from the other two, as replacements, in case of breakage.
When I rebuilt the machine, USB/E-SATA external drives were common, and easier to use than the removable bays, as every modern computer has at least USB sockets, so that's what I use now. I still have one removable bay in one machine, but the same hard drive is in it almost all the time. Most of my installations are on the external drives now. The one I'm typing this from is on the third partition of a 1 TB SATA drive in a USB/E-SATA case. This particular computer has no SATA connectors, so I'm using the USB connection. There are four other computers in the house, that have E-SATA connectors so I use the E-SATA cable with them.
The main reason for having the IDE drives being the boot drives is so that you don't
have to change the settings in each menu.lst. If they are always (hd0) they are ready to boot in any machine. If they are (hd1) on your current machine, everything would need to be changed if you wanted to boot from that drive in another machine, then changed back when inserted in the current machine.