Date   : Sun, 15 Feb 2004 10:03:28 +0000
From   : Mike Tomlinson <mike@...>
Subject: Re: Unknown chip

In article <Marcel-1.53-0213215929-0b0xSBG@...>, Johan
Heuseveldt <johan@...> writes

>In the process of cleaning, one of the BBC machines has a small box - which
>I had forgotten about - with a few roms and an unknown chip (to me) in it.
>The unknown chip is a plastic DIL, 2 x 12, and the texts are:
>
>  CN48415N
>  00201752-01
     ^^^^^^^^^
This is the Acorn part number.  I can't open your .zip file (Winzip says
it's not a valid archive.)

Are you sure it's 24-pin?  IIRC, the only 24-pin chip in the Beeb is the
6850 ACIA (serial chip), but that will be clearly marked as such, and
it's a Motorola, not Acorn, part.

If it is actually 28-pin, and given that you found it in a box of roms,
I'd plug it into a ROM socket, switch on, and do a *HELP to see if it
responds.  If not, try jumping into it with *FX142,n where n is the ROM
socket number to see what is printed on screen.