As a nice give away you also get an 8080 CPU for free. There have been two solutions AFAIR. One was booting MS-DOS and starting a bootloader for CP/M80 (a), the other was a CP/M disguise for MS-DOS (b). The Bootloader programm loaded an 8080 BIOS which supported hard MS-DOS Hard disks into memory, did setup the memory tables for the 8080 and switched into 8080 mode to boot CP/M from HD. There where several problems regarding disk storage, so the system worked only reliable from floppy disks. I heared also about a Version which booted from almost ordinary CP/M floppies. All switching code fitted into the PC boot sector. I never had this version, and I didn't play a lot with the hard disk version, but I used the other programm (b) for several years. You could start CP/M programms right from the MS-DOS command line, or switch into CP/M command line. The Programm itself replaced CP/M and redirected all CP/M functions to MS-DOS functions - thanks to the similarities :) There where even 'utilities' to switch DOS pathes wihile in CP/M, etc. pp. The performance was quite acceptable (faster than a 8080 at 5 MHz), and you could use almost all PC Hardware. I used this programm to run CP/M applications for several years under MS-DOS - I never had the time to redo them for the PC. I even kept the XT some time as CP/M machine when I already had an 386. The machine was also equipped with a screamer add on board, so the CPU was running most of the time at 8 MHz.