Date   : Sun, 03 Jan 2010 13:44:36 +0000
From   : pete@... (Pete Turnbull)
Subject: Floppy cable switch

On 03/01/2010 13:29, Mark Usher wrote:

> I wanted to add a switch to my dual disc drives to swap the drive IDs round.
> 
> Ie. Drive 0/2 becomes 1/3 and vice versa.
> 
> As would be expected the drives are jumpered ID0 and ID1. Is it possible to
> put a switch in the floppy cable to swap the two around similar to the twist
> in a PC cable?

Sure, you just need a switch to change over DS0 and DS1.  That's not 
what a PC cable twist does, BTW.

What you need to do is cut the lines for DS0 (pin 10) and DS1 (pin 12) 
in the cable, insert a double-pole double-throw (DPDT) switch:

BBC end                                            drive end
                   o-------+------------------ 10 ------------- 10
10 ------------o---       |
                   o----+--)------------------ 12 --------------12
                        |  |
                   o---/   |
12 ------------o---       |
                   o-------/

The red stripe on the cable is pin 1, so 10 is the tenth wire from that 
edge.


-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York