wrote in message
oups.com...
I think you will find an "idle keyboard", no key pressed, will be a
continuous mark tone.

Paul, KD7HB

Quite right. The 'diddles' you hear are often Letters character being sent
to stop the machine from getting bored.
By the way, I saw it mentioned that a Stop bit was 2 units long? I've always
thought it was 1.5.

Nana