Richard Cini wrote: For my final year engineering degree project, I co-wrote a Z80 simulator in somewhat pre-FORTRAN-77 to run on an IBM 4381 running MUSIC (under VM). The college planned to use this to teach students about microprocessors but I don't know if this was ever done. Not having much use for a Z80 simulator myself, I later rewrote it as a 6502 simulator and then converted the core of the simulator from FORTRAN to IBM 370 assembly and later still, VAX assembly. It can run the BASIC rom from the BBC Micro but not the OS rom. Instead some mainly text based OS functions are emulated/simulated directly. Software such as text based adventure games for the BBC Micro can be run on the simulator but anything relying on graphics, sound or trying to play directly with the hardware doesn't do so well. I didn't go on to have any input into MS-DOS or Windows :-) Regards, Peter Coghlan.