I've done a lot of searching. Here are good links that I have found

http://www.sandisk.com/tech/oem_design/cf_dc.asp

http://www.ata-atapi.com

http://www.t13.org/

but they are mostly about the ATA/IDE interface, that is the easy part. What seems to be globaly missing is good solid information on the 'file management' firmware needed to interface with the FAT12/16/32 formats. I know that sandisk has it for sale at $8,000USF, which I find a bit pricy for us just to be able to use their product.