TTY Inquiry

[Guy Harris]

> Currently under Bell UNIX, data communications for ttys are
> uni-directional.  For example, once a port is conditioned to send out
> data, it can not readily receive data.

What?  When I log into a UNIX system, I can type at it at the same time it's
typing at me.  What do you mean by "conditioned to send out data"?  You
can't have one process blocked on a "read" on that port and doing a "write"
on the port at the same time on any current UNIX.  Programs like "cu"
usually work by having two processes, one doing the reads and one doing the
writes.

	Guy Harris