Commercial HP01 emulator for android.
  • for ease of use, displayed as a classic look alike.
  • quartz synced with android time, so good accuracy.
  • automatic save and load of state.
  • alarm beep only when time displayed.
  • stopwatch beep at zero only when displayed.
  • dynamic calculation supported
  • no timeout on displayed information (battery is no more a concern ...)
    Not an exact replica of the HP 01, the rom is taken from a preproduction patent # 4158285: ie there is no % function on this emulation.
    It is best to get a manual to use this emulation.
    A better display as a watch will follow

First release:
  • should work with at least 600x480 screen.
Time (24 hours mode)
Date (21 century) 
Alarm (set) 

Some technical details:
  1. re type the rom listing from patent 4158285
  2. make a cricket assembler
  3. check proof the rom 
  4. use patent 4158285 to emulate cpu and display module (more complicated than a classic calculator)
  5. try to fully understand the internal format to have a good accuracy on time, stopwatch and alarm
  6. make a 'nice' calculator like skin to debug it
  7. ....