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Date   : Thu, 23 Mar 2006 11:25:55 +0000
From   : "Thomas Horsten" <thomas.horsten@...>
Subject: Re: re:want to buy a MOS 3.50 chip

Hi Raf,

On 23/03/06, Raf <rafg1@...> wrote:

> Could you do what you describe below for me and post it, in the usual
> safe manner to me in Australia?
>
> Do you have an all-up figure in mind for the cost of this job?

Well, I wouldn't want to make a profit on it and I do have all the
parts at home since I bought an extra of everything in case something
should go wrong (which it didn't). If you just want the parts and the
flashed chip and are prepared to solder the bits together for the
adapter yourself I can put a kit together and send it for £5.36 (cost)
+ postage.

Here's some excerpts from an email where I explained how the adapter is made:

The needed components are (with Maplin codes in parentheses):

1 x 0.6in 28 pin socket (FZ63) £0.79
1 x 0.6in 32-pin socket (FZ65) £0.79
1 x 32 Socket Strip (DC17T) £0.79
1 x M 27C1001-10F1 EEPROM (AW34M) £2.99

Some connection wire (didn't buy that, since I already had some, but I
guess something like BL49D would do).

Let's assume all the components are lying on the table facing up, with
"pin 1" indentation up (like the pictures on Andrew's page,
http://www.adsb.co.uk/bbc/adaptor.html).

Cut 28 pins from the socket strip and stick it into the entire left
side of the 28-pin socket (pins 1-14).

Cut another 7 pins from the socket strip and stick it in the right
lower side of the 28-pin socket (pins 15-21).

Cut another 5 pins, and stick them just north of the previous one,
with one blank in between (pin 23-27).

Now solder a wire on to pin 22 (the blank one), make sure it doesn't
get too tall. Solder the other end of the wire to pin 2 of the 32-pin
socket.

Cut off the thin part of pins 24, 30, 31 and 32 of the 32-pin socket.

Solder a wire on the stump of pin 24 of the 32-pin socket. It is
important that it doesn't protrude too far down. Also solder wire on
pin 1 and pin 16 (pin 16 must be soldered *above* the thin part so the
thin part can still be stuck into the socket strip later. This was the
trickiest part of the whole job for me, and I am really horrible at
soldering so if I could do it almost anyone can).

Now connect the free ends of the wires from pin 24, 16, and 1, by
soldering them together.

Finally you have to solder pin 31 and 32 of the 32-pin socket
together, and a small piece of wire from pin 31 of the 32-pin socket
to pin 28 of the 28-pin socket. Pin 30 of the 32-pin socket must not
be connected, just cut it off very short.

You are now done, all you have to do is to stick the 32-pin socket
into the strip connectors (the bottom of both sockets should be
aligned, ie. pin 16 of the 32-pin socket goes into pin 14 of the
16-pin socket etc). Just double check that pin 24 on the 32-pin socket
is not touching pin 22 of the 28-pin socket (there are solderings on
both "floors"), if they are then cut some of the excess tin off.

Then you just stick the programmed 27c1001 into the 32-pin socket, and
the Master should now boot up.

I've posted a couple of pictures of the contraption here:
http://www.infowares.com/bbc/

Since I use a GoMMC, I used 2 extra 28-pin sockets to raise the GoMMC
so it doesn't touch the new Megabit ROM with the adapter. If you have
a GoMMC as well

> I take it that you would be copying genuine ACORN material?

You have a choice there, I have the original ROM image complete with
Acorn bugs, and also one that I patched with Andrew Benham's Y2K patch
(http://www.adsb.co.uk/bbc/bbc_master.html) and his DFS patch
(http://www.adsb.co.uk/bbc/dfs.html). I'm using the patched one in my
own Master and it works perfectly. But if you prefer I can burn the
original image as well.

Thomas
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