Re: [PARPORT] Scanners using parallel ports

Philip Blundell (
Fri, 30 Apr 1999 10:36:54 +0100

>Can you give me some idea of the kind of obstacles ?
>I guess that if it comes up often then it might be worth writing it :-)

The big one is that PC parallel ports are bi-directional but you have to
explicitly turn off the line drivers to make them inputs. Without some prior
knowledge of when you need to do this, it's hard to pretend to be a

If your protocol works only in nibble mode then it would be a lot easier and
probably the only limitation there would be the speed at which you can sample
and update the port.


-- To unsubscribe, send mail to: --
-- with the single word "unsubscribe" in the body of the message. --

This archive was generated by hypermail 2.0b3 on Fri 30 Apr 1999 - 05:41:56 EDT