J80 is one Z80 Emulator written in JAVA with included a standard BIOS for complete Microcomputer with working CP/M 2.2, CP/M 3.0 and one simple ZX Spectrum 48/128K emulator. The spectrum 128K version emulation is not complete but working. The best gol of this emulator is that the 'hardware' is build on the fly reading the configuration form one file in this way is very simple add new peripheral or features. For more details see the documentation. It is possible download more CP/M program here.