I love the HP-45 calculator. It's beautiful on the outside, but I
wanted to show people that it's beautiful on the inside, too. So, as a
coding and retrocomputing challenge I decided to rewrite an earlier,
terminal-based simulator of mine in Python (but with standalone
executables), with a GUI. As with all such 'just a few days on this'
projects it spiralled out of control, and the result is HP-1973.

It not only runs (included) ROM code from the HP-45, but also the
HP-35 and the HP-80. You can select which calculator you wish to use
when the application starts, and also have the option to choose
between multiple ROM versions for a given calculator (with warnings if
a ROM is known to contain bugs). In total, six calculator-ROM
variations are included.
