Duck Tales 2 Repro

Hi guys,

I want to try my hand at doing a repro and have chosen a game I always wanted to have, but never got hold of. Right now I have a Silent Service cartridge as a donor, which should be the correct board.

My doubts come with the EPROMS I have to get for this project... I don't know much about them besides what they are and how are they used. What I mean is that I don't know if the pinouts are compatible directly (I do know there are many exceptions and that it would imply soldering some pins differently).

Which kind of chips do I have to buy? Are they the same for PRG and CHR? And, related to this... which are the RAM chips I would need to buy if I were doing a CHR-RAM repro?

Anything you can tell me would be very useful.

Thanks in advance!

All chips larger than 64KB are not directly compatible with Nintendo boards and will need rewiring.


For the NES, most 8-bit EPROMs, EEPROMs and FlashROMs will work. The basic part numbers that are known to work well are 27CXXX (EPROM) and 29CXXX (FlashROM). The XXX indicates the capacity of the chip, in kilobits, Which means that a 29C256 can hold 32 kilobytes (divide by 8 to convert kilobits to kilobytes). You can use larger chips for smaller games, so don't bother looking for smaller chips if you can get the larger ones.


If the game uses CHR-ROM, they can be the same, but in many boards the CHR must be wired differently from the PRG (the original chips have different pinouts).


If the board you're using already uses CHR-RAM, you can leave that as is. You only have to change the PRG-ROM. Converting a CHR-ROM board into CHR-RAM on the other hand is not very trivial, because most carts don't even have the pin that carries the CHR write signal, so you have to somehow hack a new pin into the cartridge edge.

Im sure Duck Tales 2 uses UNROM with IMO is the MOST ANNOYING board to do.

The reason is, for 128KB chips, Nintendo uses 28 pin mask roms, but the EPROMS are 32 pins. Now for games that use an MMC1 mapper and up, there are extra holes already drilled into the board. But this uses the mapper before it (74xx161 and 74xx32) and only has 28 pins drilled into the board. Where the chip lies on the board theres a resistor you have to desolder and flip around, otherwise the chip will lay ontop of it and you'll never get the cart to close.

Retro USB used to make a RetroPak board which was awesome for these games BUT they stopped .

BUT there is a solution! Konami made their own boards (and UNROM board too, just not named UNROM, its 351258) that switched around the board a little and you'll have some more room to work with. But not all of those games have a Konami board. If the back of your Silent Service has a '24' printed on it you're good. Altho I don't think they made them for Silent Service. The Konami sports games usually have them and pretty easy to find, like Double Dribble, or Skate or Die.


I know this because I went to make Megaman and got all these problems until I did more research.

Thanks everybody for the tips, I'm going to check my Silent Service cart and see if there's any luck.

Hi, I just used a top gun 2 digit code 12 found here.

http://bootgod.dyndns.org:7777/profile.php?id=341

I wired according to NA thread.
http://nintendoage.com/forum/messagevie ... adid=79927

pin 1 don't touch
pin 2 bend up and connect to hole 22 (under pin 24)
pin 24 up to GND, usually pin 16
pin 30 don't touch
pin 31 up and leave disconnected
pin 32 connect to pin 30, not necessary to bend

The game loads fine and plays but soon as you start playing the left side and top score area gets overran w/the level as you move. Any ideas?

I used rom from dope roms and a am27c010 eprom

Contra, DuckTales, and DuckTales 2 use horizontally arranged nametables ("vertical mirroring" in iNES lingo). Ikari Warriors and Top Gun use vertically arranged nametables ("horizontal mirroring" in iNES lingo). A mismatch is likely to cause scrolling problems. Do you see H and V solder pads on the Top Gun PCB? The V pads for vertical arrangement are probably bridged with solder. Desolder it and bridge H.

I just had someone on Atari age who makes repros tell me about this and he made me look it up lol. He said I would never learn unless I knew what it was. Yes this was the problem. The v had the solder blob. I removed it and put it on the H and it works perfectly.

Thank you for answering. You seem to always know the answer to things as well.