Thanks to Jeff Parsons who created an emulator environment that runs, among other platforms, a virtual Superboard II computer (also known as the Challenger 1P), you too can enjoy the wonderous experience of programming a 6502 home computer based upon a teletype input system.
This is exactly how I learned to write both BASIC and 6502 machine code from magazines such as 'Computing Today' and 'Byte'.
The BASIC interpreter in the machine ROM was written by a little-known company called Microsoft.
Unfortunately, this implementation may not function properly on a mobile device due to the way the key presses are registered.
However, if you are using a laptop or computer with a modern web browser click this link to start the emulator Fire It Up
if you have not used an actual Superboard or C1P before, I strongly suggest reading all of the text on the emulator page to learn how to get the system to operate.