[SWLUG] Serial ports

[Steve Anderson]

On 31/07/06, Steve Hill <steve at nexusuk.org> wrote:
> On Mon, 31 Jul 2006, Justin Mitchell wrote:
>
> > first off, make sure that the cable has been wired so that the CD line
> > is asserted, otherwise you will have to fiddle around to avoid it.
>
> I've never found anything that really cares much about the CD line.  You
> certainly shouldn't have any problems just echoing stuff to the port.
>
> The problem is normally the DSR and CTS lines - if they aren't asserted
> and you have hardware flow control on then the UART just plain won't flush
> the TX buffer to the port.

Well, thanks all who chipped in. Got it working a treat last night, as
the entry on the Makezine blog testifies!

http://www.makezine.com/blog/archive/2006/07/display_fun.html

I think it was probably a good idea to start with a null modem cable
because the wiring was set up nicely before I took my wire cutters to
it. The DCD line caused no issues, the only thing that did was the
idiosyncratic naming of serial ports on my Thinkpad when it's docked
(/dev/ttyS1 and /dev/ttyS8, with nothing else between them).

Thanks again!

Steve

-- 
Irregular Shed - http://www.twindx.com