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From: hutton@nic.cerf.net (Tom Hutton)
Newsgroups: sci.electronics,rec.games.video
Subject: Re: Nintendo Cartridge Internals
Message-ID: <258@nic.cerf.net>
Date: 17 Dec 90 19:44:09 GMT
References: <1990Dec10.172238.18313@msuinfo.cl.msu.edu>
Followup-To: sci.electronics
Organization: CERFnet, La Jolla, CA
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In article <1990Dec10.172238.18313@msuinfo.cl.msu.edu> gurney@eecae.msu.edu (Eddy J. Gurney) writes:
>I took apart one of the non-working cartridges, and inside there was a
>VERY tiny circuit board - which surprised me from the size of the plastic
>case.  First question: Are all the circuit boards for Nintendo cartridges
>the same?  This one says (C)1987 Nintendo on it, and has four ICs, two
>resistors, and a capacitor.  

No,  The simple games use the board you describe.  Other games have
additional chips and hybrids.

>
>The four chips are as follows:
> . One labeled (C)1989 Nintendo (16 pin DIP)

This is their security chip.  There is an identical one in the NES system
and it if the system does not correctly communicate with the cartridge
chip, the game will do random resets.  Atari had reverse engineered
the chip and were going to make their own cartridges and a lawsuit 
was started.  Im not sure if the outcome has been settled yet.  Nintendo
will not sell you a chip.

> Finally, there are two 28 pin DIPs that appear to be ROM's.  One is labeled
The roms are program rom and graphics rom.  They are standard jedec pinouts
and might be masked or eproms.  Try getting a datasheet on a 
27256 prom for pinouts ( I dont have a databook with me today)

The screws are easily removed by using the correct screwdriver - try going
to a tool supply house.


----------------------
Tom Hutton
SDSC