based on:
- emu8080 by Stefan Tramm
- ShellInABox and its marvelous VT100 emulator by Markus Gutschke
  (http://code.google.com/p/shellinabox/)
- js8080 by Chris Double (http://www.bluishcoder.co.nz/js8080/)
- z80pack by Udo Munk (http://www.unix4fun.org/z80pack/)