reset() and save() question

getting worse now after playing around with HID:

>reset();
=undefined
 _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v89 Copyright 2016 G.Williams
Uncaught SyntaxError: Got ?[255] expected EOF
 at line 1 col 1
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^

Question:
How can I reset the puck's memory to factory default?
reset() doesn't seem to work or have side effects.