This emulator is capable of providing a faithful replication of the HP48. In order to do so, it requires a copy of the ROM software from YOUR calculator. In order to avoid breaking copyright laws, and upsetting HP, you MUST BE THE PROUD OWNER OF AN HP48 before running this program. Of course you can run this program without a copy of the ROM software in order to write trivial machine code programs but you will not be able to access any of the calculator functionality. WWW: http://home.earthlink.net/~rmmlgetz/