Awesome program!  I played with my brother's '41 long ago, and now I have one of my own!  There are few oddities I'd like to mention:

* BEEP is not a single tone, it's a specific 4-tone sequence.
* LCD font looks terrible, it's all fuzzy and translucent.  LCD segments should be solid black.
* Shift key should not enter the current value; Shift-CLX doesn't work because of this.

That's all for now.