[plug] serial cable length (was: PPP Connection)

[Kevin Shackleton]

Our office used to have (pre 10BaseT, pre-10Base2) some serial cables around the
building that we used for several purposes, including Laplink.  Laplink would work
at 115 kbps on all but the longest run of probably 50 m, certainly well over 20 m.
I think we could run the long link at 57 kbps, but it might have been 38 kbps.

That was using proper shielded serial cable implementing all handshaking.  In fact
I think that Laplink used the handshaking lines for parallel transmission, rather
than handshaking (?).

K.

Denis Brown wrote:

> Matthew Skinner and Leon Brooks contributed thoughts on cable length for RS232.
>
> There is a page at http://www.connectworld.net/cable-length.html describing
> recommended maximum spans for various protocols.  In the early days when
> 9600 bps was in the outer limits of communication speed 50 feet, about 16
> m, was recognised as the limit.  I saw a 1200 bps link working over 700 m
> with xon / xoff  for flow control but the signals were just little
> half-sinusoidal blips.  Miracle that it worked!
>
> Cheers,
> Denis