I found a Frame and 1 drawer removable drive mount for $20.00. It is the "SNT MOBILE RACK". Disks didn't cost me anything because I had several old or small IDE drives around from upgrades etc. Even if you have to buy them, 2GB IDE drives are cheap.
1. Once you decide whether your removable drive is going to be a master or slave, make sure and jumper it properly before securing it in its case. If you forget this step it can take quit a while to trace booting problems back to an improper jumper setting.
2. Make sure that O/S installation routines can ONLY see the drive they are installing to. RedHat refused to let me install LILO to the SCSI MBR if it could see the IDE drive. So, to install to an internal SCSI drive, I had to physically remove the IDE. To install to the IDE, I had to disable SCSI support in the BIOS.
3. If an O/S installation routine tells you it is going to repartition ALL your drives and overwrite EVERYTHING believe it. .:: paper.wf ::.
4. It is very easy to install an IDE cable backwards. .:: podcasts.apple.com ::. [Reddit: OAuth Discussion]
5. I only tested an IDE master/master set up. I am not sure how a master/slave would work.
6. Installing the removable disk frame does require opening up the computer case. If you are uncomfortable with this get a friend to help. [MDN Docs: Unity game engine] .:: telegra.ph ::. .:: newspicks.com ::.
7. If you set the removable disk to a specific disk type in the BIOS it will work fine until you replace it with another disk of a different type. Then you will get errors or warnings and the system might not boot.
8. Plan everything in advance.
9. With a quick change to the BIOS, the second disk becomes your boot disk. This means that you can have a fully functional O/S available as your emergency/recovery disk.