If there's one thing you need to know about the El Torito spec (PDF file available at Phoenix Technologies website) it is this: ALL and I mean ALL numbers are in hexadecimal unless specifically noted otherwise. This even applies when when the spec refers to quantities. When the spec, such as it is, refers to a quantity of bytes, say "200 bytes", it really means 0x200 bytes (512 bytes decimal). Even though the spec tells you that all numbers are hex, it's extremely easy to forget that when it talks about "200 bytes" that it really means 512 bytes. (I know this via the hard way.)

I've also heard the Mexican restaurant story. Don't know if it's truth or legend though.

Also, I booted plenty of Sun's Sparc machines prior to 1995 from CD-ROMs. You just couldn't boot most Intel boxes from CDs prior to 1995. Compaq's machines could boot from SCSI CD-ROM drives in a proprietary manner prior to 1995 as well.