Date   : Fri, 01 Jun 2007 13:02:44 +0100
From   : dm.hunt@... (David Hunt)
Subject: PC/Beeb serial cable woe

> > My cable is the same as Dom's, I used 4 individually screened core 
> > cable and I get a reliable 19,200 baud over 5m. It works on 
> all my PCs 
> > including a
> > 1989 vintage 386, I just set the port for CTS/RTS hardware 
> flow control.
> 
> I have found that a 4-core cable will often work in practice. 
> But there must somewhere be a common 0V line. So if the cable 
> is working, and there is no dedicated 0V line, then the 
> system has to be relying on something else. This must be 
> either the screening (which must be connected at both ends), 
> or else the common earth (via the mains plug).
> 
> Although these may work in the right circumstances, it seems 
> less chancy to connect the 0V pins together to make a proper 
> signal ground.
> 
> David Harper 
> 

The screen of the cables is ground. I can't see how an additional ground
wire is going to make any difference?

Dave ;)