Date   : Mon, 24 Jul 2006 18:29:28 +0100
From   : "David Hunt" <dm.hunt@...>
Subject: Re: DFS Explorer 1.0.1 For Mac and Linux Released

> Ok, I've now tried another beeb with an 8271 in it and a 
> Watford DFS ROM. I got the same response at first, until I 
> found that beeb serial ports allow the cable to be plugged in 
> upside-down ;)  (cable's label now annotated to make sure I 
> don't do that again :-)
> 
> With things the right way up I now see the BASIC listing 
> transfer on the beeb's display (it seems that even if the 
> cabling's wrong the sent data just vanishes into some giant 
> buffer somewhere and DFS Explorer doesn't know that it's not 
> actually getting to the BBC)
> 
> It's not helped matters much, though. After I run the 
> beeb-side prog and kick off a transfer, I see the same data 
> (*DISC)in the transfer window, then after a pause I get 
> "Timeout waiting for response" in the transfer window (wasn't 
> seeing that before) followed by the same "problems changing 
> to DFS" error dialog.
> 
> I've just tried xfer just to validate that my upside-down 
> cable hadn't damaged the receive channel to the PC, but all's 
> well there - so it looks like it's a software problem, either 
> with DFS Explorer or with the BASIC that runs on the BBC side :-(
> 

It's always worth checking the serial port with a terminal emulator in the
OS of your choice first.

e.g.

*FX 8,7
*FX 7,7
*FX 2,1

Then on the PC with 9600 baud, 8 bit, no parity, 1 stop bit... Type
something and it should appear on the Beeb screen

I think you can achieve the reverse by using *FX 3,1 and everything you type
on the Beeb should appear on the PC.

The PC serial port needs to be configured for hardware flow control using
CTS and RTS and should also have an IRQ assigned to it.

I haven't connected the Beeb to the PC for ages, I'm a bit rusty...

Dave ;)