Use the files in this folder in your Arduino IDE. This is the development code. Use the folder IoTBASIC for the stable code.

TinybasicArduino.ino is the sketch file with the main interpreter code.

basic.h is the header file with the function prototypes and static variables of BASIC.

hardware-arduino.h is the hardware abstraction library.

Before building BASIC, edit TinybasicArduino.ino and the select the language set you want to compile. Follow the instructions in the wiki https://github.com/slviajero/tinybasic/wiki in "How to compile".

You also need to edit hardware-arduino.h and select the hardware options. This is explained in the wiki as well.