Hi Peter, You did a great job on the isolinux and memdisk tools.. I can know, I've also written a CD-Rom disk emulator, only it's slow (read from the CD) uses 22KB conventional memory (mainly cache) and the emulated floppy image cannot be written to. http://www.nu2.nu/diskemu/ You're memdisk is fast, small conventional memory footprint and the emulated drive is writeable, very, very, cool!!! I (together with someone else) have written a real-mode Dos CD-Rom driver "eltorito.sys" (only 4KB) that supports a bootable CD-Rom drive in "no emulation" mode, using INT13h/ah=42 read calls to get the block from the CD device... Very handy for Dos based boot disks that need to have hardware independent CD-Rom support... At the moment it has some small bugs, but when it is stable maybe you can mention it in your memdisk documentation... One small question, can isolinux also chainload NT CD-Rom bootstrap loaders? They are 2KB in size and have a 0x55AA signature at the end... I've tried: label bcnt4 kernel bcnt4.bs But isolinux says: Loading Invalid or corrupt kernel image. boot: Best regards, Bart. -- Bart Lagerweij Mailto:bart at cts-bv.nl -- CTS, Computer Technology Systems B.V. Oosteinde 85, 3925 LB P.O. Box 113, 3925 ZJ Scherpenzeel GLD The Netherlands Phone: +31 (0) 33-277 1447 Fax: +31 (0) 33-277 1360 Homepage: http://www.cts-bv.nl --