Date   : Sat, 04 Nov 2006 11:31:34 +0000
From   : pete@... (Pete Turnbull)
Subject: DFS on 3.5inch - Is this supposed to work?

Richard Gellman wrote:
> Mark Usher wrote:
>> Don't forget, when using 3.5 inch drives on a BBC B (not master) with 8271
>> controller, to use JGHs patched DNFS ROM.
>>   
> Ah now, see this is a complication.
> 
> What does the patched ROM do that the original DNFS (which is in my 
> model B) doesn't? Is this relating to the index pulse suppression 
> mentioned in another post? (my apologies to the author for forgetting 
> their name...)

It retries "forever" on certain errors, where the original DNFS and DFS 
would eventually give up.  Yes, it is to get round the error caused by 
index pulse suppression, but that suppression only happens on certain 
modern PC drives.  It's not a problem with all modern drives, and not a 
problem with any older BBC/Master-era drive that I've ever seen.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York