A Radio Shack TRS-80 Model xtrs I/III/4/4P emulator is a Radio Shack TRS-80 Model I/III/4/4P emulator for Unix and X Window System. xtrs emulator includes tiny, real-Time Clock, hi-res graphics, serial port, parallel printer, mouse, cassette, sound and music production (requires OSS), 5 "and 8" floppy drives for singles and double density, and drives.The same disk formats emulated floppy and hard drive files are compatible with popular MSDOS-based emulators by JEFF Vavasour, Matthew Reed, and David Keil, and (if you choose a file format capable enough), all features of the original TRS-80 floppy controller is emulated. Under Linux, physical disk drives are also supported. Physical Tapes can be read and written too. The user interface is a bit spartan, but it gets the job done.