Terminal emulator for ASR-33.

Features:

• Pygame and Tkinter frontends.

• Backends for pty (Linux/Mac) and ssh (Paramiko library)

• Limits output to an authentic 10 characters per second. Hit F5 to make it go faster (toggle on tkinter frontend, hold on pygame)

• Scrolling (with page up and down - tkinter frontend has a scrollbar)

• Output a form feed to clear everything

Various bugs and to-dos:

• No user interface to select between frontends and backends. For now, edit the script.

• Speed throttling (whether through the backend or throttle.py) does not work well on Linux. It works on WSL, and the last time I checked this technique worked on macOS. You'll still get the 10-chars-per-second output, but interrupting long outputs won't work.

• Most of the fun termios functions (echoprt, echok, kill, reprint, discard) don't work on WSL

• Add tty-37 support (half lines, reverse line feed, and lowercase). For now, the forced uppercase can be disabled by editing the upper() function

• Add backends for wslbridge and msys/cygwin.

• Improve graphics, better font, allow "ink spread" for overstruck bold.

• Simulate classical 'stty lcase' line discipline for input of upper/lowercase letters and `{|}~ (part or all of this are broken in modern OSes)

• Discard and regenerate scrollback to limit memory usage. The AbstractLine class I created should be useful for this, but nothing is hooked up.