I once typed in and ran the MOUSE.MOVE program to test my Mouse IIc. Unfortunately i don't think i ever used it after that. It was apparently purchased at CompuShop for $99. This would be around 1984, when everyone but me had abandoned the Apple ][ for the Mac.
What about this mysterious line?
120 POKE -16368, 0 : REM CLEAR KEYBOARD STROBEGoogle has made Beagle Brothers obsolete: "IF PEEK(-16384)>127 then a key has been pressed (POKE -16368,0 resets this)"