Date   : Mon, 03 Dec 2001 02:18:01 GMT
From   : pete@... (Pete Turnbull)
Subject: Re: Help!!

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

These are static RAM chips; they won't plug in to the Beeb anywhere.

>           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).
 There should be more numbers on them.  What are they?

>           NEC 8227k9 D7002C

That is the ADC chip, used for the analogue port.  The Beeb will work
without it.

> I have slots free in the main ROM slots (next to the vine micros one)

The leftmost is where the MOS goes; BASIC goes in any of the other four.
 The farther to the right it is, the higher the priority it will have.

You probably also need to replace the links on S21; there should be two
links running east/west.

> and I also have 2 free towards the middle left of the board near the
> power supply.

Those are for the speech upgrade.

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.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York