gurney@eecae.msu.edu (Eddy J. Gurney) (12/11/90)
Last weekend I was at a local Swap'N'Shop (Amateur Radio related) and I
bought three "non guaranteed to work" Nintendo carts for $20.00. They
apparently were from a video store that rented the things, and had gotten
trashed somehow. I took three of the nine or ten the guy had, figuring it
wouldn't be too hard to clean the contacts or whatever, assuming it was
something simple like that. =) Anyway, two out of the three don't work
at all; one of them is screwed up - the graphics are all "trashed" - kind
of like what happens when your programs accidentally starts storing stuff`
where the video memory is mapped. :-) Anyway, SOMETIMES, the last game is
playable, and the characters are just slightly skewed, other times it's
hopeless.
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. It also has two "jumpers", one labeled "H"
the other "V". The "H" jumper is connected while the "V" jumper is open.
Second question: What does this select?
The four chips are as follows:
. 74HC161 - which is a 4-bit binary counter with asynch reset. It is
capable of being loaded also. Third question: Any idea what
they do with this? Is it used to divide the clock from the
main NES box? This one is easy to replace if it's the
problem (although I doubt it... the easy ones never are the
cause of problems!)
. One labeled (C)1989 Nintendo (16 pin DIP)
I assume this is a PLA; probably something to do with their
monopoly on requiring something special in the cartridge for
it to work in the NES. Fourth question: Anyone know any
specifics about this chip? (Or maybe references to other
articles on it?) If this chip is the bad one, I presume it's
impossible to get, and I'm SOL.
Finally, there are two 28 pin DIPs that appear to be ROM's. One is labeled
as PRG, the other as CHR. The PRG chip says "M38128B-13" on the second line.
The CHR chip has six numbers on the second line; unfortunately, I'm doing
this from memory and I can't remember what it says. I suppose it's
conceivable the ROM's are fried from a static zap to the connector. Anyway
to tell?
The cap appears to be a bypass cap from the top of the circuit board to the
bottom.
Anyway, anybody have any info on what all this stuff is? Maybe pinouts on
the ROM's (if that's what they are?) Anybody else take apart any other
cartridges? Are they similar to this, or does each manufacturer use their
own boards? I haven't taken apart the other two yet; I pretty much hacked
the first case, thinking the circuit board was going to be big. If they're
all this small, it's a simple matter of sticking a screwdriver to pry the
case open near either of the screws at the connector end. Slowly push in the
screwdriver til the case pops - this allows enough room to let the cartridge
slip out, and the only damage to the case is that one of the screws is
missing.
Any information or references would be greatly appreciated; I'll post a
summary to the net if I receive any replies.
aTdHvAaNnKcSe,
Eddy J. Gurney, N8FPW
--
Eddy J. Gurney, N8FPW THE ECCENTRICITY GROUP
eddy@jafus.mi.org -- gurney@frith.egr.msu.edu -- 17158EJG@MSU.BITNET
(Preferred) (But this is OK too) (Only if you have to :-)00nacooper@bsu-ucs.uucp (Ho Ho Ho. Merry Christmas from SocrateS) (12/11/90)
In article <1990Dec10.172238.18313@msuinfo.cl.msu.edu>, gurney@eecae.msu.edu (Eddy J. Gurney) writes: > Last weekend I was at a local Swap'N'Shop (Amateur Radio related) and I > bought three "non guaranteed to work" Nintendo carts for $20.00. They > apparently were from a video store that rented the things, and had gotten > trashed somehow. I took three of the nine or ten the guy had, figuring it > wouldn't be too hard to clean the contacts or whatever, assuming it was > something simple like that. =) Anyway, two out of the three don't work > at all; one of them is screwed up - the graphics are all "trashed" - kind > of like what happens when your programs accidentally starts storing stuff` > where the video memory is mapped. :-) Anyway, SOMETIMES, the last game is > playable, and the characters are just slightly skewed, other times it's > hopeless. > > 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. It also has two "jumpers", one labeled "H" > the other "V". The "H" jumper is connected while the "V" jumper is open. > Second question: What does this select? > > The four chips are as follows: > . 74HC161 - which is a 4-bit binary counter with asynch reset. It is > capable of being loaded also. Third question: Any idea what > they do with this? Is it used to divide the clock from the > main NES box? This one is easy to replace if it's the > problem (although I doubt it... the easy ones never are the > cause of problems!) > . One labeled (C)1989 Nintendo (16 pin DIP) > I assume this is a PLA; probably something to do with their > monopoly on requiring something special in the cartridge for > it to work in the NES. Fourth question: Anyone know any > specifics about this chip? (Or maybe references to other > articles on it?) If this chip is the bad one, I presume it's > impossible to get, and I'm SOL. > Finally, there are two 28 pin DIPs that appear to be ROM's. One is labeled > as PRG, the other as CHR. The PRG chip says "M38128B-13" on the second line. > The CHR chip has six numbers on the second line; unfortunately, I'm doing > this from memory and I can't remember what it says. I suppose it's > conceivable the ROM's are fried from a static zap to the connector. Anyway > to tell? > > The cap appears to be a bypass cap from the top of the circuit board to the > bottom. > > Anyway, anybody have any info on what all this stuff is? Maybe pinouts on > the ROM's (if that's what they are?) Anybody else take apart any other > cartridges? Are they similar to this, or does each manufacturer use their > own boards? I haven't taken apart the other two yet; I pretty much hacked > the first case, thinking the circuit board was going to be big. If they're > all this small, it's a simple matter of sticking a screwdriver to pry the > case open near either of the screws at the connector end. Slowly push in the > screwdriver til the case pops - this allows enough room to let the cartridge > slip out, and the only damage to the case is that one of the screws is > missing. > > Any information or references would be greatly appreciated; I'll post a > summary to the net if I receive any replies. > > aTdHvAaNnKcSe, > Eddy J. Gurney, N8FPW > > -- > Eddy J. Gurney, N8FPW THE ECCENTRICITY GROUP > eddy@jafus.mi.org -- gurney@frith.egr.msu.edu -- 17158EJG@MSU.BITNET > (Preferred) (But this is OK too) (Only if you have to :-) I'm not sure about the technical side of things, but as for the size of the chips, i have opened up a couple, and they are all small(at least the Nintendo, I don't know about Tengen games) There is a way to take out a chip without doing ANY damage to the chip: on the reverse of the game, there are screws(on the older games) or another kind of screw(on the newer ones). I'm not sure how to do this on the newer games, but you can use a very small screwdriver to take apart the older games. The newer ones may have rivets instead of screws, I'm not sure about this. Well, I hope this helps a little. Nathan Cooper
kiuchi@sumax.UUCP (Usagi Yojimbo) (12/13/90)
The way the games are put on the Nintendo "cartridges" is by they are fed the program by a source machine whatever.. In the same way that a record is made, the source code is put onto the circuit board as a meal.. or program.. that is why they are impossible to copy. Or if they could be copied you would need a lot of equipment (probably which would cost more than buying each game). Anyways, that is what I know from Japan, when they were first there, a person could go to a machine (like buying a coca cola) insert the yen.... let their cartridge be fed a certain code, and THUS erasing the old game..
hutton@nic.cerf.net (Tom Hutton) (12/18/90)
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