Really really fast BASIC handheld

[mfleming]

Skimming through the online manual for more information, a "slot" seems to correspond to a project, which can hold multiple text and data files. Basic programs are saved as text files. It would seem you are not limited to just four programs.

A slot or project can be saved to or loaded from an SD card, so you can transfer to or from a PC. They specify the Unicode character set used by Basic and provide a downloadable font set, so I assume a suitable editor could work with a Basic program file.

Hummm, 3D Free42 anyone?
~Mark