Ultimate Boot CD

I know you could use the simple boot loader to boot a system from a floppy, then select the CD drive to continue booting, which is usefull if the BIOS doesn't have the option to boot from CD. My problem now is that I have CD drives that won't get recognized by the PC's BIOS as a CD Drive (PCCard Adapter, another is USB). Is there something similar I could use for such CD Drives?

Thanks for any help.