Date   : Tue, 11 Feb 2014 22:48:35 +0000
From   : pete@... (Pete Turnbull)
Subject: Paged ROM board

On 11/02/2014 20:24, Peter Coghlan wrote:

> Rather than experience the pain of sourcing a replacement 74LS163, I went to
> have a look at what was in the box of Beeb related spares and found this:
> 
> http://www.beyondthepale.ie/board.jpg
> 
> I can't recall where I got it, probably in a box of miscellaneous stuff in
> an electronics shop.
> 
> The only identification on the board is "SIR COMPUTERS Ltd 1983" except for the
> giveaway legend "BBC ROM" beside the two pin header where a flying lead is
> plugged in and a tiny etched "rom 2" at the bottom left.  Given that there are
> also twelve 28 pin IC sockets labelled IC0 to IC11, it appears this is a
> sideways ROM board for the Beeb.

Yes, it's a sideways ROM board for a Beeb, though yours is missing the
pins.  I wrote a review of one for the Micrognome pages back then, and
I've still got that board.  It's moderately awful.  The pins go into the
6502 socket, which, the pins being too big, it destroys.  Or at least
makes unfit to be returned to normal use.  They weren't very reliable.
We called them surfboards.  I guess if you were to fit decent dil pins
(not wirewrap pins, which is what Sir Computers used) it might not be
too bad.  Mine has the same ICs but fewer links and is a slightly
different layout, with a wire-wrap socket where SKT1 is on yours, and
that's what goes into the 6502 socket on the Beeb.  Yours seems to be a
little later.

The label on mine is where your IC73 is, and is black vinyl with a
caricature of a top hat and an eye, and the legend:

SUPPLIED BY
SIR COMPUTERS
91 WHITCHURCH ROAD
CARDIFF
TEL: (0222) 21341
            621813

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York