[jacquesm]

I see what you're getting at. That the next character would start to be printed before the carriage return had completed with the sending side not respecting the fact that it had just sent a carriage return by waiting for a bit.

From what I remember most TTY drivers would automatically insert an appropriate delay after a CR because the LF is optional, you can happily overprint a line if you want.

[mark-r]

I remember a system that overprinted about 5 characters to black out a password after you entered it. Good times.

The NUL character was useful for inserting a delay into the serial stream.

[jacquesm]

Hehe, security by obscure it y.

And in sync links (not TTY's those were mostly async with start and stop bits, more like HDLC style stuff) those nuls were mandatory, you had to send something.