Date   : Tue, 03 Aug 1999 11:50:40 +0100
From   : Philip Blundell <pb@...>
Subject: Re: Econet hardware 

>The 75159 (the line driver) should be socketed on all model Bs.  It's a
>very common failure point on Econets, causing the line to jam.
>
>We used to get ours from the RS catalogue - do they not stock them any
>more?

I don't think RS have stocked the 75159 for several years now.  I'm surprised 
the 74LS74 isn't still available though.

Fortunately the drivers for the Master-style interfaces are (slightly) easier 
to get hold of.

>I seem to remember Acorn made the mistake of soldering the 75159 on
>early B+'s,

I've seen many model B's with soldered in parts as well (both 75159s and the 
LM319 receivers).  I suspect it depends mostly on how lazy the person who 
fitted the upgrade was feeling at the time.

p.