Ok I found this tutorial that shows how to configure pxelinux for booting a disk image.
Only problem is, it uses version 3.80 of pxelinux (it states the version earlier in the tutoria), which is very old (current version is 5.0). I have also heard that pxelinux supports booting ISOs (not just floppy images as used in the tutorial, so I assume this is a new feature that requires a version beyond 3.80). I was able to get it to boot a floppy image of MS DOS, but it won't boot a CD ISO, so I assume the older version can't do this.
However the commands used with the older version are different than the new version it seems.
The old version of pxelinux uses these commands commands with the old MEMDISK in order to boot a floppy image (these commands are to be placed in the "default" configuration file).
MENU LABEL ODIN
The new versions of pxelinux and MEMDISK are supposed to use these commands instead (as found on the pxelinux wiki http://www.syslinux....dex.php/MEMDISK) it seems:
It appears in the new version that you use an INITRD command instead of the APPEND command for naming the disk image.
Also it appears that the KERNEL command has been replaced with the LINUX command. However I'm not sure these are replacements, or just alternate commands that are completely interchangable, or if they are somewhat different from each other and each has a separate use for slightly different situation (with little overlap in what they are designed to accomplish, sucht that they aren't usually interchangable).
Some help making sure I'm using the correct commands, and a tutorial on how to use the LATEST version of pxelinux and memdisk would be VERY HELPFUL. Please someone, make this tut for me.