Date   : Thu, 04 May 2006 22:55:48 +0100
From   : Chris Johns <chris@...>
Subject: Re: Mystery Item

> The wedge was a teletext adapter.  The chips are 2 x quad opto isolators 
> and 2 buffer chips. The cables are user port and printer port.

It looks like some home-grown "buffer box". Often used for connecting
things to your beeb, the idea being it would buffer the signals so you
didn't fry 6522s.

We had some in school, both "Devon Buffer Box" units and own-made ones.
They connected to the user port and gave you handy chunky connectores to
plug your lights, motors etc into.

They were used them for computer control projects.  By using the printer
port as well, you could get another 8 output lines (plus I think two
inputs).

Looks like someone made use of a teletext 'wedge' for their
construction.

Cheers

Chris
-- 
Chris Johns <chris@...             >