Date   : Tue, 29 May 2007 17:34:52 +0100
From   : ats@... (Adam Sampson)
Subject: PC/Beeb serial cable woe

"Kris Adcock" <beeb@...> writes:

> The first thing that confuses me is that the textfile's description
> of the five-pin DIN plug (the ASCII-art of it) seems to have pins 4
> and 5 swapped around compared to the numbers inscribed on the plugs
> I've bought. Can anyone confirm this?

Yes -- I think there are a couple of competing standards for numbering
the pins on DIN plugs, and I ran into exactly the same problem when
building my PC-BBC serial cable from that description. Use the picture
rather than the numbers.

The other problem I had is that the DIN plug I've got will fit into
the BBC either way up, so I needed to carefully label which way up
it's meant to go.

> The other thing that confuses me is that the textfile doesn't have
> the 0v pins on the two plugs wired together - there just seems to be
> four wires that go from one plug to the other. Is this right?

No -- you must join the ground pins together too. Otherwise, the
description in the xferc documentation is correct; that's how my
cable's wired.

(I'm not actually using xferc, though; I knocked up my own tools to
send disk images to the BBC:
  http://offog.org/darcs/misccode/bbcserv
  http://offog.org/darcs/misccode/bbcget.bas
Dunno if those are of use to anyone else...)

> As far as usage goes, I'm setting the Beeb to transmit and receive
> at 9600 baud, and then set the input to serial port, like this:
> *FX 7,7
> *FX 8,7
> *FX 2,1

That should do the job, but 9600 baud doesn't work reliably for me; I
get dropped characters if I try to do that. 4800 baud's OK.

-- 
Adam Sampson <ats@...      >                         <http://offog.org/>