Serial Port Noise: how can you detect it?

A Little known command: "!", that is the exclamation point
symbol by itself: !
If it is placed somewhere in code, the code will stop there
until ANYTHING is received via serial communications on ANY
port.

Example:

WHILE 1==1 'while forever
! 'wait here until anything comes in via
comms.
PRINT("noise",#13)
LOOP

Now so much as a noise glitch hits the serial receive
buffer, the motor will print noise out the port.
Keep in mind, anything deliberately sent will cause it to
print "noise" as well.