Using PICAXE with Scratch

The PICAXE BOT115 Create board (or any other board fitted with a PICAXE-18M2) can be used as an input device to the original Scratch software by emulating the officially supported Scratch interface, which is called ‘picoboard’. The PICAXE board provides up to 7 sensors to the Scratch program (note that the original MIT build of Scratch does not control output devices, as the picoboard is an ‘input only’ device).

You will also need the AXE027 PICAXE USB cable to connect the board to the computer.

Fonte e mais detalhes aqui.