Date   : Mon, 03 Dec 2001 09:56:49 +0000 (GMT)
From   : Sprow <rsprowso@...>
Subject: Re: Help!!

On Mon, 3 Dec 2001 pete@... wrote:

> On Dec 2, 12:08, George Reynolds wrote:
> 
> > However i have the problem that I have the main system roms sitting on
> top of the case and I don't know where to put them. They were of course in
> the watford board :D
> 
> > I have 8524 HM6264LP-15 T00008010 *2
> >           Acorn 8417
> >           Acorn 8421
> 
> These are presumably the MOS and BASIC, but I can't tell which is which
> from those numbers -- they're just the date codes (date of manufacture).

One will have either PB05 or B05 on somewhere,which is BASIC.
The other will have PB01 or B01 on somewhere,which is the MOS.
Though as Pete stated later,you've a one in two chance of guessing!

Other 'my beeb wont turn on' diagnosis are covered at
 http://www.sprow.co.uk/bbc/doctor.htm

> If you plug the ROMs back in, make sure you get them the right way round --
> notch towards the rear of the machine.  If you plug the BASIC where the MOS
> should be and vice-versa, you'll do no harm, but it won't boot.  So that is
> a quick way to figure out which is which :-)
> 
> However, the Watford boards (and some others, notably not the ATPL boards)
> had pins that were much too big for the sockets, and it's probably deformed
> the sockets so they won't make reliable contact with the ROM pins.  The
> only real cure for this problem, if you have it, is to replace the sockets.

Splaying the pins a little so that they grip the metal at the outer edge
of the socket may also help,
Sprow.