The XO-1 laptop is only capable of mono input, the XO-1.5 and XO-1.75 are capable of stereo input on their microphone socket and can graph two signals at once.
'''Note:''' As of Measure Version 37,
old versions of Sugar, e.g. 0.84, are no longer supported.
[[File:Measure tut 1 24.jpg|center|300px]]