I know several people here want to know how to make reproduction cartridges, myself included, but it takes a lot of knowledge and technical work to make them. I have a very good concept of how to make them but could just never pull it off. I'm very willing to learn.

I propose that somebody act as our "professor" and everybody who wants to learn "enroll" in an online class to teach users here to make NES reproduction cartridges. Of course that's a big favor to ask to the professor role, but we can pay that person with NES items if need be. And it would be doing a huge favor to me and anybody else who wants to learn how to make them. The "class" could take place in a public thread on NintendoAGE so anybody who has an account here can learn if they want to.

What do you think of this idea? And to anybody who knows how to make them - Would you be willing to teach people who wants to know?

I'd be willing to provide any advice, I haven't actually replaced any NES rom chips, but have done it to a gameboy before - main difference is NES has 2 chips compared to 1 on gameboy, and gameboy is 5 times smaller!

Key things in creating a repro/homebrew cart:

Identifying the memory mapper of rom

Idenifying rom size

Find donor cart / Retro Zone cart

Find eprom or eeprom

Burn eprom or eeprom

Desolder rom chips

Solder chips/sockets

Play game

Drink beer

Other interesting topics:

Erasing eproms

I have always wanted to learn as well and sounds like a cool project for sure.
~~NGD

I think Leon K has some stuff over on NesDev.

He's the guy that runs "NES reproductions"

Well I know how to make them, if anyone ever needs any help, I'd be happy to oblige. I'm not much of a tutorial writer though :/ Now that Retro Zone sells repro boards (though they can't do a whole lot of types of boards) and CIClones, that simplifies things quite a bit. I'd like to see some repro boards that support like the MMC1 and MMC3, even though you'd still have to desolder those parts from a donor cart, you still wouldn't have to screw around with fixing the ROM pinouts (which is the biggest pain in the ass IMO).

Ok, I am going to try to figure this out again, and I'll post all my questions here to be answered by BootGod & Zzap (and anybody else who knows and can help).

First question - I own a Willem EPROM programmer. They were the cheapest programmers I could find that looked like they can get the job done so I bought one. There are a bunch of DIP Switches on the bottom of the programmer but I have no idea what they do.......do the DIP Switches need to be at a certain spot for it to work right?

Second question - I have a bunch of 28 pin EPROMs that are 27C512. The only problem is I don't exactly know what '27C512' means. How much space can these EPROMs hold exactly? Also, I read somewhere that if EPROMs are exposed to any kind of static they will completely erase and become useless. Is this true? And what do I need to do to make sure they aren't exposed to static?

Q1: I'm not really that familiar with the Willem programmer, but from the look of it, the software should give you a diagram showing you how to set the dipswitches based on the chip type selected in the software. There's also jumpers that need to be set in the right places based on diagrams in the software too.



Q2: a 27C512 is a 512KiloBIT chip, which equates to 64 kilobytes. Note to erase an EPROM, you will need a UV light eraser. There appears to be fairly small ones around for relatively low prices these days. Several years ago I made one using an old PC case and a UV fluoro tube from an aquarium store. Worked damn well, but scared me at the same time



Link to the pinout for the 27C512: Eprom Pinouts

The gist of how they work is you have Address pins (A) and Data pins (D). Depending on which Address lines are active, the Data pins will show a byte of data for that address. There's other pins to enable the chip, enable writes, and enable output, but the main things to know about is the address and data pins.

One of the things you can do is wire a physical switch to the highest address line so that the physical switch switches between the lower and upper 32k of your chip. This can be used to put 2 32k games onto the one chip effectively Note that for the NES, you will need to EPROMs, one for the Program memory, and one for the Character memory.

Link to further details about E/EPROMs: Link

uCON64 can be used to split a .nes file into its component PRG and CHR files: uCON64

You *may* screw up an EPROM with static, but I've never done it before. I'm not sure, but the modern electronics just seem so much more resistant to static. Anyway, *could* buy an anti-static wrist strap and connect that to something earthed while you worked with the chips, or you could just use them You can also keep them in anti-static foam.

I'm no expert, but here's some data on how I've done some games in the past.  I cut and paste a lot of this from my own MS Word document where I keep track of everything, so my fonts and indentation are all over the place.


Step 1) Get your .NES ROM.  The game you want to repro.

Step 2) Run that ROM in Nintendulator. 
When Nintendulator starts up, select  "Debug"->"Status Window" from the menu.  This will show you information about the ROM itself.  Important things to note are
- Mapper Number
- PRG size
- CHR size
- Mirroring
- Some of the other flags like battery backup, etc..

Step 3) Obtain donor carts that matches those criteria. 
Bootgod has a database with lots of info on it but I'm not sure if its public so I didnt post a link.
  You can also use this page on nesdev:
http://www.parodius.com/~veilleux/boardtable.txt
You will save yourself a lot of time for NROM,CNROM and UNROM repros just by using the ReproPak from www.retrousb.com.  Then you dont need any de-soldering or re-wiring.  Thats perfect for Bombsweeper, California Raisens, HeroQuest, Labyrinth, Pescatore (very buggy), Egypt, Hotman, and Badminton.

I mentioned carts (plural) for 2 reasons. 
a) If you have never de-soldered before, you will likely wreck the carts until you get the hang of it.  
b) Its extrememly useful to create a test cart using sockets.  By doing that you can test if your EPROMs have been programmed correctly.


Step 4) De-solder the CHR and PRG chips from the board. 
( For UNROM, there is only a PRG chip since the CHR is RAM so you leave it alone).   What I have found to be useful is to snip the old chip off board using IC snips, and then use de-soldering braid and a soldering iron on each pin.  The braid sucks up the old solder, then you can flick off the pin. If the solder doesnt come out, add some new solder and try again.  The new solder mixes with the old and comes out better.  This is the stage where people damage the board.  Oh yeah, this is the stage where you burn yourself.


Step 5) Getting to know EPROMs.
27 series EPROMS and 29 series Flash chips are what people use.  The pinouts are the same (as far as I care).  EPROMS are cheaper.  Flash chips do not require a UV eraser to re-program them. Usually when you buy a new EPROM, its been blanked, but it doesnt hurt to buy an UV eraser as well.
The numbers indicate the size.   27C256 EPROM and 29F256 Flash chips are of size 256 kilo bits.  (the keyword there is bits).  You divide that number by 8 to get kilo Bytes.  The PRG and CHR sizes are in kilo bytes.

You should probably get chips that are 150 ns in speed.  Dont go slower than 200 ns.  I have no clue about chipds faster than 120 ns.

The naming gets a little weird for larger chips.  27C010 and 27C1001 are the same. These are 1024 Kilo bits (or 128 Kilo bytes).

27C256, 27C010 and 27C020 will be the most common sizes you use.

Step 6) Prepare the data.
You need to split the CHR and PRG data from the .NES rom you have.  A link was provided in an earlier post to a utility to do this.
You must then "fill" the entire EPROM. 
Lets use Bombsweeper as an example.  Bombsweeper is homebrew game by SnoBro based on the Game and Watch game.  Its an  NROM game with a 16 KB PRG and 8KB CHR.    But the 27C256 chips each hold 32 KB of data.  You need to double the size of the PRG and quadruple the size of the CHR.

Lets pretend the PRG file is called bsweep.prg and we want the final file to be called bSweep32.prg.

You can do this in a Windows console window by executing the following:
copy /b bSweep.prg  /b bSweep.prg /b bSweep32.prg

You'd do it 4 times for CHR
copy /b bSweep.chr  /b bSweep.chr  /b bSweep.chr  /b bSweep.chr /b bSweep32.chr

Step 7) Program the chips
Every programmer is different, but they usually behave in a similar fashion.
You plug in the programmer, load up the programmer application,  load in the binary file for the PRG.  Insert the PRG chip (put it in properly) and program it.  Usually the programmer will do a blank check, a program, then a read which is verifies against the binary data you loaded.  Insert the CHR chip and program it as well.   You might also want to label the chips.  Use a little sticker and cover the EPROM window with it.
Some things that are good to know:
a) Programmers that use USB as their power supply are probably programming the chips at a value lower than it expects.  Therefore the chips may not last 25 years before losing their data.   If you can use an external power supply, you probably should.
b) With Willem programmers, there is usually a diagram showing how the DIP switches and jumpers should be set for each type of chip.  Make sure you match them.  If you get them wrong you may wreck the chip.
c) Dont put the chip in backwards.  There's a little notch to use a a reference.

Step 8)  Setting up the proper mirroring
MMC1, MMC3 etc.. carts do their mirroring programatically, meaning theres nothing to solder.
If you are using NROM, CNROM or UNROM (and maybe AROM) you need to indicate the mirroring.   Mirroring has to do with background and scrolling in NES games. 
If you are using a ReproPak, you need to follow the instructions provided when you bought it.
Otherwise, you are using a donor. On the board there should be 2 letters  H and V usually below the CHR chip.   If you have Horizontal mirroring, you need to have a solder blob for the V.   If you have Veritical mirroring, you need a solder blob for the H.  I know that sounds backwards, but its not.  You can use solder braid to remove the old one if you need to switch from one to the other.

Step 9)  Soldering in the chips.
This is where a ReproPak will make your life so much easier.  If you have it, follow its directions.  Otherwise you are using a donor and may need to do some re-wiring.
Either this step or the de-soldering step is the hardest one. 
I'm not going to try to write all this out. NESDEV deserves the credit.
http://www.nesdev.com/NES%20EPROM%20Conversions.txt

Things to note:  NROM and CNROM do not need any additional wiring done.  These are good ones to start with.  UNROM uses only one chip, so it is what I would try next.
Since you cannot do MMC1 or MMC3 games with ReproPak yet,  those are a good area to pursue.

I dont follow the NESDEV directions for UNROM, and I dont exactly know why I do things differently.  Here's how I do it for UNROM PRG

1. On the 27C1001 EPROM, bend up pin 1, 2, 24, 31, 32.



2. Place wire from pin 1 to pin 30, 31, 32 on the EPROM.



3. Place a wire from pin 2 to the socket hole corresponding to pin 24 (hole 22 on a 28 hole board)



4. Place a wire from pin 16 to pin 24 on the EPROM

Try not to break any chip legs.  30 gauge wire is fine.

Step 10) Test it out, put on a label and have fun.
Sometimes its tough to get the board to fit back in the cart, dont worry about it. 

Al

Excellent tut!

Thanks for sharing that Al, very freaking cool. I have a place to start when I get some extra money now
~~NGD

A couple of things to note.

- Step 9 which involves the re-wiring is the hardest step, at least when using 32 pin EPROMs.   The link I provided is pretty good, but it doesnt hurt to actually buy a repro and use it as a reference.  Sometimes seeing it is easier than reading it.
Its also a bit easier to do the chip to chip re-wiring before doing the chip to board re-wiring.  Meaning steps like "connect pin 1 to 31" should probably be done before doing a step like  "connect pin 1 to hole 24", or something ....

- I think everyone should try to design at least one label themselves. I really hated the Recca labels, so I did my own using a scren shot of the Recca soundtrack.   Try to do it at 600 DPI and using dimensions 2.17 x 3.82 inches.  
Figuring out an economical way to get them printed so they look good and are laminated is a real challenge.  If anyone has info, please post it.  I own a xyron sticker maker, but its a real pain to use.   If someone could print, laminate and cut these, there would be a market for them from people who dont want to deal with that hassle themselves.

- I used to think there was a big markup on NES repros by people making them, but honestly I dont think that anymore.   Once you make one yourself,  you'll see what I mean.  I honestly can't imagine making a FF3 proto myself.   I've bought one and I am amazed by the amount of work required.

Al

Al covered it pretty nicely I use a Willem programmer too, Nick, in order to setup for one of your 27C512's, you'd select that chip from the device menu (Device->EPROM->27Cxxx->27C512) and the images will change to show you exactly how you need to setup up the switches and whatnot. I wouldn't be too concerned about static electricity, it could be an issue, but I've handle lots of stuff like this with minimal concern for that and never had a problem.

The DB Al mentioned is no secret and you can check it out here.

Bootgod,  do you use an external power supply for your Willem programmer, or just USB power. 
Al

For the longest time I had used just USB power and had no problems, but then not too long ago I started started having problems writing to chips so I tried unplugging some other USB devices from the system first and then it worked fine again. I've read that it often isn't able to pull the power it needs from the USB bus, so to be on the safe it probably wouldn't hurt to just use an external PS. IIRC, you can use a 9V or 12V, and you need to set a jumper to make it use the external source instead of USB. Actually I want to say there are jumpers to set the voltage level as well, I would have to double-check.

And how much current does your power supply has to give ?

This is very nice and something I want to do cause I can do it for my Playchoice too.
Thanks

I couldn't tell ya. I would think 500ma would be plenty.

Are these for sure the "official" measurements?  Any word on how much of the 3.82 should be given to the top part of the label?

  I think the top part is 9 mm.

I dont know about official, but try printing one off and cutting one out and see how it looks. 

Al

Probably not the "official" dimensions, but it sounds like the'll work just fine.

I'm buying some more stuff and am going to try to reproduce California Raisins by myself, stay tuned to see if I can do it or not (and probably a lot of questions too).

Hey nick shoot me a PM if ya have any questions. i had no idea that you started a thread for repros and just found it today (i forget we have a Brewery section now lol). ive made a few different repros myself, Super contra 7, Super mario 2 JAP version. And its pretty easy once ya get the hang of it. And i would have shared all the info i have as well, but i see al already has lol.

couple things i can contribute on how i made them
#1 I use the things called Flush Cutters can be bought offline at Radioshack.com, i use them to snip off one side of the pins on the mask roms. These work great for this
#2 I use a Desoldering Pump, it was very cheap like 8 bucks, and it works great.
#3 I use a program called CajoNES to split NES roms. This program is sweet and basically ya just put a rom in it and it automatically splits it into a CHR and PRG file for ya.
#4 Then i use a hex editor to Data Mirror the file for programing
#5 B data mirroring, i mean basically pasting the rom file in a hex editor, then keep repasting it in there until it fills up the size of the Eprom your using. For instant if a PRG file is 64KB and your Eprom is 512KB. Then you will have to copy and paste the PRG file over and over again 8 times. Then hit program.

Its all pretty easy to do, and i was gonna be a dealer for them, although since the release of the powerpack there is really no need to now lol. So id be happy to share Any info with anyone who wants to do it. its pretty fun. As for the desoldering, its very easy if ya have someone to help ya. Me and my firend desoldered boards in about 10 mintues. hope this help :-)

Ok I am going to try to reproduce California Raisins, using boards at RetroZone. I am going to buy:

RetroPak, Clear Case, 64KB EPROM (2), 74HC161 Mapper

Is anything else needed? What exactly is the CIC chip for and do I need one to reproduce raisins?

And here's another question: How do I match up the Mapper # to each type of board? For example, I opened the California Raisins ROM in FCE Ultra and it said it uses mapper #2. That's fine, but how do I find out which type of board is necessary (for example: U*ROM, A*ROM, etc).

For this step, I had to go to www.NESReproductions.com..., find out that 1943 was a suitable donor, then go to the boardtable and find out that 1943 uses UNROM (and therefore Raisins must also use UNROM). Is there any easier way to do this?

One more question:

Let's pretend my EPROMs have been exposed to static. Can I simply put them in an EPROM Eraser and erase them, then burn data onto them again? Or after they're exposed, does that mean they're dead forever?

(sorry for so many questions, I'm sure I will have many more though)

If you open the ROM in Nintendulator it tells you both the mapper number and what board it usually means.
Here's some help though.
Mapper 0 = NROM
Mapper 1 = MMC1 ( SNROM,SVROM,SLROM, etc.. )
Mapper 2 = UNROM
Mapper 3 = CNROM
Mapper 4 = MMC3 (TKROM means battery, TSROM means CHR RAM, TLROM means no CHR ram)
Mapper 5 = MMC5


California Raisins is Vertical Mirroring.

You only need one chip, a 128 KB PRG chip (27C010) since UNROM games contain CHR RAM instead of a CHR ROM.

If you use the retrozone parts you'd need:
- Board $5.00
- Casing $3.50
- 27C010 EPROM $2.50
- 62256 SRAM Chip $2.50
- 74HC161 mapper ($ 0.50)
- 74HC32 mapper ($0.50
- CiClone chip $3.00 (this is the security chip, you may not want it if your console has been modded to bypass the security chip 

$17.50 in parts



If you think your chip is bad, it never hurts to erase it in the UV Eraser.  Then put it in your eprom programmer and double check that its blank.   Make sure you set all your jumpers correctly.

I have 2 different programmers, and even though both claim to be able to program all my chips, in reality they dont.   My dual power one wont write my 256 KB flash chips, and my Top2005 programmer wont write my 32 KB flash chips.


Al