Date   : Tue, 06 Dec 2005 20:10:13 +0000 (GMT)
From   : Greg Cook <debounce@...>
Subject: Re: BBC B+ with faulty disc interface

On Tue, 6 Dec 2005 00:49:55 +0000, Ian Wolstenholme
<BBCMailingList@...> wrote:

> Yes, I am using a known good drive and a formatted disc.  There is
> not
> even a disc error, nothing happens until you press ESCAPE.
> 
> I suspect it may be a botched job of a disc upgrade as links S3 and
> S8
> are made with a bit of insulated wire rather than a jumper or a 
> solder track and the 1770 itself does feel ever so slightly loose. 
> (It's not
> socketed).

Perhaps the connection to the NMI line hasn't been made or it's broken,
causing the controller to sulk because of late register service. (This
also happens if the controller raises more NMIs than the filing system
is expecting.)  It may just be a matter of re-soldering a dry joint(s)
on the 1770 as all other mods have most likely been done.

Also IMHO using wire to make links (soldered or wirewrapped) is
legitimate and recommended, provided the wire is as short as possible.

Greg Cook
debounce@...
http://homepages.tesco.net/~rainstorm/



               
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