Newbie Here: Help me get started

Are you new to 6502, NES, or even programming in general? Post any of your questions here. Remember - the only dumb question is the question that remains unasked.

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mitchondria
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Newbie Here: Help me get started

Post by mitchondria »

Hello everyone,

The names Drake, Im a NES video game collector and have alot of donor carts sitting around gathering dust. Ive been looking into reproduction carts for awhile now, just on games that were never released (Bio-Force Ape, Earthbound Zero, ETC).

I have talked to people that sell them and they want some ridiculous prices, especially when its something I feel like I can learn to do myself. Im a computer technician full time so I feel pretty knowledgeable in tech. But ive never pursued programming eeproms.

Can anyone give me any info to get me started? I know I need a programmer, but not sure what Type kind im looking for (since im lacking in chip knowledge).

Thanks everyone...
tepples
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Post by tepples »

There are three scenarios:
  1. Making carts to play. The easiest way to do that is with a PowerPak.
  2. Making carts to sell. We sort of frown on that here, unless they're homebrew games licensed to allow distribution on carts for a fee.
  3. Making carts to be able to show in a collection.
You're a C, right?
mitchondria
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Post by mitchondria »

Yes deffinately a C.

Im wanting something that look original when I play it or have it shelved. I have some cartridges like double dragon which the nesproduction guy uses on his list to make his repro that he sells. Im not interested in selling them, just wanting to add them to my collection.
mitchondria
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Post by mitchondria »

Im really really wanting to play bioforce ape, but dont want to do it on a pc and emulator cause it just doesnt feel real.

I need to be able to blow into the cartrisge just in case,you know for that vintage feeling lol.
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tokumaru
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Post by tokumaru »

This has been asked TO DEATH in here, and if you look around you'll find tons of topics that start with messages that start just like yours.

I'll give you a basic rundown of the process anyway:
-Find out what mapper/board the game uses;
-Find a donor cart that uses the same (or very similar) mapper/board;
-Remove the ROMs from the donor board and make adaptations if it's not a perfect match;
-Split the ROM into PRG and CHR (not always present) sections;
-Program the EPROMs/FlashROMs, replicating the files until they fill the entire chips if necessary;
-Compare the pinout of the original ROM against the pinout of the EPROM/FlashROM;
-Solder the EPROMs/FlashROMs, cutting traces and rewiring pins to overcome the differences identified in the previous step;
-Test;

Bootgod's database is great for looking up board/mapper information. This table is useful too, but it's not as complete.

Splitting the files can be done with an hex editor, but there are a couple of tools for this.

You can look up the data sheet of your EPROM/FlashROM in this site to get its pinout, and this document has the pinouts for different Nintendo ROMs. Whatever doesn't match has to be rerouted.

I believe all EPROM programmers work for the common 8-bit chips that are used with the NES, so you don't have to worry too much about chip support. Make sure you get a USB programmer though, because there are still many parallel port programmers around and those are sometimes a pain to get working on modern computers.

As for the EPROMs, the 27CXXX series is commonly used. The XXX represents the size of the EPROM (Note that the size is specified in KBits, not KBytes: you have to divide by 8 to convert from KBits to KBytes - 256KBits = 32KBytes). From 1024 up sometimes they use 010, 020, and so on. FlashROMs also work great on the NES, specially the 29CXXX series.
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rainwarrior
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Post by rainwarrior »

The cheapest EPROM programmer I know of is the TOP853 (~$35 on eBay), which is okay for this purpose but requires Windows XP and has a very poor English translation in its software.

If you want to reuse EPROMs you might also want an EPROM eraser (little drawer with a UV light and timer), also pretty cheap on eBay (~$20). Alternatively you can get OTP EPROMS with no erase window, and hope you get it right the first time.

If the game is using a specific simple mapper, you may be able to get all new parts from retrousb. Currently it's charging $12 for a PCB, case, and lockout chip. In addition to this you will need a couple of capacitors (~<10c each) your CHR/PRG EPROM or SRAM chips (~<$5), and possible a discrete logic chip or two for the mapper (~$1). Check the ReproPak manual for instructions.

For more complicated mappers, people usually cannabalize a suitable donor cart, for which you only need to replace the PRG/CHR chips with your own EPROMS, with a little bit of creative wiring.

You also need a soldering iron and solder, obviously. For donor carts you need an NES cartridge screwdriver bit. Other tools can help with removing old chips (desoldering braid, desoldering pump, dremel, etc.).
mitchondria
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Post by mitchondria »

Thanks guys for the help. tokumaru, man you make it sounds so easy but im a bit lost on a whole when it comes to the process. IM a noob at this lol.

Im going to start looking for a eeprom programmer and eraser.

Is using the donor eproms a good idea? I know that these chips are very old now and im not wanting to run into issues.

My other question is I have a Retron 3 for my kid, and was wondering will the repro im going to make be compatible withit (cause i know some games are not). I have the original NES hooked up in my game library but im sure he would stick some kind of lego or something in there to play lego game.

Sorry for not looking up this info before hand. I did a search and the topics were a bit overwhelming so im trying to centralize the info for me.
mitchondria
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Post by mitchondria »

can anyone suggest an eprom programmer thats compatible with Windows 7 64 bit OS?

Im not wanitng to spend a bunch on this FYI
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rainwarrior
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Post by rainwarrior »

I think the Willem USB programmers are the next cheapest option after the TOP853, and they seem to go for around $65?

I don't know what you mean by "donor EPROM", but the ROM chips in a donor cart are not reusable (they are hard-wired mask ROMs, not EPROM). If you mean "can I use old EPROMS I got from eBay", then the answer is "usually", but be sure to erase them first (though an EPROM programmer can tell you if it's blank before it starts programming).

Compatibility should be the same as with the original game, if you did the repro correctly.

Also, if you're using new parts with a ReproPak you can skip the lockout chip if you don't need it to run on an unmodded original NES (top loader and clones like Retron 3 do not normally have lockout devices).

If you don't want to spend a bunch, someone else already suggested it, but the PowerPak will get you hundreds of games on one cart for a price comparable to what it will take you to set up and build your first repro.
mitchondria
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Post by mitchondria »

thanks rainwarrior. I was under the impression I could take eprom out of donor cart and clear and reflash. Guess this isnt the case.

The powerpak would be a great idea except im wanting something more than just playing these. Im wanting to be able to display them individually on my shelf (as a stand alone copy)

I actualy have a small laptop running a slimmed down version of XP SP3 so the Windows 7 compliancy isnt really a need.

I found the TOP853 for 43.00 free shipping. But thats the best ive been able to find (which isnt really that bad).

So what exactly is the donor cartridge supplying anyway? Is the repro basically just programming the rom onto an eprom and soldering into a donor board with the required circuitry to make it work?

Im also going to take this a step further, I own a website (ThumbstickGamer.com) where we do like reviews, previews and just anything to kill time, and ive been thinking about programming a game using xna. But if I can get this figured out Id love to program my own adventure and create a gamecart for a giveaway (sounds pretty sweet). But one step at a time...
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rainwarrior
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Post by rainwarrior »

You will need to learn what a mapper is. It is a critically important concept for understanding how NES cartridges work.[/url]
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tokumaru
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Post by tokumaru »

mitchondria wrote:I was under the impression I could take eprom out of donor cart and clear and reflash. Guess this isnt the case.
Original carts don't use EPROMs, but ROMs that are not reprogrammable. Some pirate carts do use EPROMs, though.
So what exactly is the donor cartridge supplying anyway?
Most NES games have more than just the game code in them. The extra hardware is used to expand the capabilities of the system, with features such as support for larger ROM sizes, more RAM, scanline counters (for raster effects), more audio channels (only on the Famicom), etc. We call the hardware that does this a "mapper", and the NES has a shitload of possible mappers and board configurations, which is why the donor must be a close match to the game you are trying to make a cart of.
Is the repro basically just programming the rom onto an eprom and soldering into a donor board with the required circuitry to make it work?
Yes. What complicates things a bit is when the pinouts of the chips don't match (this is always true for > 32KB) and when the board isn't an exact match (so you have to do things like add RAM, rewire traces, add pins, etc.).
mitchondria
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Post by mitchondria »

eeekkk... this is getting more and more complicated. Ok so how would I find a pin out for the prototype games?

example: bioforce ape?
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rainwarrior
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Post by rainwarrior »

Well, presumably you have an NES ROM file of Bioforce Ape and not a prototype cartridge. The pinout that matters is that of the donor board. What you need to know is which mapper Bioforce Ape uses (I believe it's MMC3, but you must verify this yourself).

So, you go find a game cartridge you want to destroy that also uses that mapper. Replace its two ROM chips with your own (rewiring a few things to accomodate different pinout between their ROM chips and your EPROMS), and you'll be done.

A link to pinout info was already posted. If you have an NES ROM and you want to know what mapper it uses, Nestopia will let you look at a ROM's header with an option in its file menu. This will give you an iNES mapper number which you can look up on the wiki: http://wiki.nesdev.com/w/index.php/Cate ... ES_Mappers


This site also has good information about donor boards, and will also do the job for you if you want to take the easy route: http://www.nesreproductions.com/
mitchondria
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Post by mitchondria »

Thanks again. I actually emailed that guy but $25 plus shipping both ways is just too expensive.

So I found out that I can use Silver Surfer as a donor cart (since I have two copies of this) and knowing how frustrating this game can be. This kinda feels good lol.

I did a mapper lookup:

http://bootgod.dyndns.org:7777/profile.php?id=1095

so what all info on here is important. I see that the games have 2 chips (one for characters and stuff, another for programming)
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