I recently ran Knoppix on an old P200 with 64M of RAM and an AMD K6/266 with 128M RAM. The trick to getting it to recognize the CD drive as /dev/scd0 is to use the "nodma" cheatcode on both computers.

On the P200, Knoppix stops in its tracks, annouces it doesn't have enough memory to run KDE, and offers to create a swap file on an existing partition (much like it creates a persistent home directory in a file).

If there's a FAT32 partition (or ext2/3) with 60M of space available, it'll work.

And it automatically finds it on the next boot.

So, no need to create a separate swap partition just to run the live CD.