Date   : Thu, 28 Aug 2008 18:51:34 +0100
From   : acorn@... (Andy Ford)
Subject: Question about 1770 DFS interface testing it on a B

Hi.

I just wondered if anyone can confirm on a B, if the usual Acorn 1770 
DFS message should show up (on startup) or with *H. regardless of 
weather the actual module is fitted to IC78 or not assuming the rom is 
present.

Reason for asking...  I have been going through my spares and faulty 
machines. I have removed a 1770 upgrade from a dead B, with the 
intention of fitting it to a working issue 7 (that already has an 8721 
DFS), as I do not have a B with 1770.

I have tried swapping the various other parts for this upgrade around 
with other spares (so I think I can 99% rule out most of the common 
components), I have hopefully narrowed it down to either the rom or the 
actual module, and I do not have spares of these to test further. The 
module had four pins missing but I managed to carefully attach some 
small lengths of wire and a bit of a broken turned pin socket to make 
four "pins", I will do it properly if it is working.

I have carefully followed the instructions regarding links etc so I am 
happy it is not a user error. I did fit one years ago for a friend...



Thanks!

Andy.