control + arrows - fine-grained movement [OS X: command + arrows]
space - pickup/drop
C - game cursor
H - hot cursor
S - solder pen
R - toggle radio
P - paintbrush
T - toolbox
[, ] - rotate
F - flip
L - load small chip
E - enter room
X - exit room
Cheat/debug:
shift + arrows - move rooms
M - dump memory usage
Note: On OS X, control + arrow-keys are bound to Apple's "Mission Control". I switched to the 'shortcut' modifier which is control on windows and command on OS X. Alternatively, you can disable
built in OS X shortcuts via System Preferences -> Keyboard -> Shorcuts.