What's the function of different snes chips is their a guide

Hi so I have been pounding my head the last few weeks with information and while I have obtained much needed info there are still a few areas I would like additional help on.

First I'm a long time collector and have a very extensive collection. My collection can be viewed in a thread at Atari age or at my photo bucket.

http://atariage.com/forums/topic/193595 ... try2754794

http://s14.photobucket.com/user/icemanx ... t=3&page=1

I will start w/what I know or at least think I know

nes games consist of 2 files chr "character" and prg "programming"
on original nes games these files can be various sizes most being 128 Kb or 256 Kb.

I will use a NES-TLROM-03 board as my discussion here.

That board has a 32 dip chr but prg can be 28 dip or 32 dip. This is where I start getting confused. Why a board can have diff. prg dips. Examples will be bases loaded 3 which has a 32 dip prg and days of thunder which has a 28 dip prg but they are both a NES-TLROM-03 board?

I have come up with this: the 32 has 4 extra pins pin 1=a17, pin 2=/ce pin 32= +5, and pin 31=+5, my theory is I could use say bases loaded donor and install a 32 dip chip and maybe program that chip staring at pin 3 and ending at pin 30 and not use the other 4 pins. Or I could just toss a 28 dip eprom in the board and not use those 4 slots at all?

As far as eproms go I have purchased some AMD AM27C128 and AMD AM27C256 chips both 150 speed. These are only 28 dips so it appears I need to get some 32 dips. However the 32 dips are not made that small. I purchased the AMD AM27C256 chips before I realized all 256 chips have to be 32 dip.

My theory from what I have read Is that I can still use these AMD AM27C256 28 dip chips for 128 files by doubling them. This now gets me to the 32 dip chips. From what I read I need to get a chip like AMD AM27C010 I am thinking 120 speed as they are plentiful. I figure on 128 files I will copy them 8 times and on 256 files I will copy them 4 times.

How am I doing so far? Thanks for all help in advance.

Smaller chips need less pins, it's as simple as that.

NES memory chips are 8-bit, meaning that each unit of information contained in them is 8 bits, or 1 byte. This means that 8 pins are necessary to carry the information out of (or into, if we're talking about RAM) the chip.

Aside from these data lines, we need address lines to tell the chip the position of the byte to be read (or written, if RAM). I don't know if you're familiar with the binary system, but with 1 bit, you can count 2 positions: 0 and 1. Add another bit and you double the amount of positions you can count, because you can count 0 and 1 with a 0 in front of them (00 and 01) and also with 1 in front of them (10 and 11). Each bit you add to the address doubles the amount of possible combinations, allowing you to count twice as many positions. If the chip has more memory positions, more address lines are necessary to address them all.

Additionally, the chip needs pins to let the power go in and out, like a light bulb, so that's 2 more pins. Finally, some control lines are necessary to to activate/deactivate the chip (sometimes multiple chips are connected to the same data bus, and they can't all output data to the same wires, so some chips have to be disabled at certain times) and tell it whether it's supposed to read or write data.

On the NES, 28 pins is enough to go up to 128KB of PRG-ROM (8 data lines, 17 address lines, 1 power, 1 ground and 1 chip enable), but you need 1 extra address line to go up to 256KB, and that would be 29 pins, so that chip has to use the next available package (32 pin). Because of the way the system was designed, CHR-ROM is different, it needs 2 chip enable lines (there are two conditions that have to be met for the chip to be enabled and outputting data), so a 128KB CHR-ROM must have 32 pins.


What do you mean "not using the other 4 pins"? These are important signals, the chip will not work properly (or even at all) if you simply ignore them...


Unfortunately, EPROMs need more signals than mask ROMs, because they need things like a programming voltage and a write/read signal, so you won't find a 28-pin 128KB EPROM/EEPROM/FlashROM. The largest programmable 28-pin chip is 64KB.


You should know that the numbers in the chip names represent kilobits, not kilobytes. A kilobyte is 8 times more than a kilobit, so the AM27C128 can only hold 16 kbytes and the AM27C256 only 32 kbytes. These are only enough for NROM or CNROM games on the NES... yeah, the earlier titles.


Yes, that chip is 1024 kbits, or 128kbytes. Chips ending in 020 are 2048 kbits (256kbytes) and chips ending in 040 are 4096 kbits (512kbytes), the largest ever used in commercial NES games. If you can, always buy the largest chips, because you can always connect the higher address lines to GND and simulate smaller chips with them (i.e. a 27C040 can be used for a 128KB game just fine, not only for 512KB ones).

Wow thanks for the info. I know there is a diff. between bits and bytes. It appears I goofed and wasted $$ on useless chips.

So it appears 128KB = 1Mb

Ahhh so let me write this out so I comprehend better lol.

1 Kilobyte KB = 8 Kilobits Kb
1 Megabyte MB= 8 Megabits Mb

so for 128 KB I need at least a 1Mb chip
and for 256 KB I need at least a 2MB chip.


So AMD AM27C010-120DC 32 dip would be acceptable for 128KB files

So AMD AM27C020-120DC 32 dip would be acceptable for 128KB files or 256KB files

So now to go back to the pin question. Lets basically skip what I said.

http://www.raphnet.net/electronique/nes ... inouts.txt

that shows prg 128KB pinouits for 28 dip and 32 dip mask roms.

Lets use the two donors listed above:

Bases loaded 3 and days of Thunder.
http://bootgod.dyndns.org:7777/profile.php?id=721
http://bootgod.dyndns.org:7777/profile.php?id=614

Both are NES-TLROM-03 boards both have 32 dip CHR roms but days of thunder is a 28 dip prg where as bases loaded 3 is a 32 dip prg.

Basically dot can't be a donor board!

I realize that looking up the pinouts that my theory would not work.

http://pdf1.alldatasheet.com/datasheet- ... 0-120.html

So would I just program the chip normally and rewire a few?

TKROM & TSROM (mapper 4):
PRG socket:
Bend up pins 1, 2, 24, 30 and 31 (or cut tracks 2, 24, 30 and 31)
Solder pin 2 to hole 24 (A16)
Solder pin 24 to GND (OE)
Solder pin 30 to hole 1 (A17)
Solder pin 31 to hole 2 (A18)
CHR socket:
Bend up pins 1, 2, 22, 24, 30, 31 (or cut tracks 2, 22, 24 and 30)
Solder pin 2 to hole 24 (A16)
Solder pin 22 to hole 31 (CE or CHR /A13)
Solder pin 24 to hole 2 (OE or CHR /RD)
Solder pin 30 to hole 1 (A17)


Whats confusing about this tutorial here is solder pin 24 to GND (OE). Pin 24 is GND OE, solder to itself?

You can still use the board. Note that even though the PRG-ROM has 28 pins, the board still has the extra 4 holes (they're filled with solder though, but you can melt it off). On the few boards I have personally checked, those holes had the correct connections. But even if they didn't, it would just be a matter of lifting the pins and wiring them to the correct places.

Forgive me for not verifying you rewiring notes, but I'm really tired right now and that requires a lot of attention...

Why did I not notice that lol. Thank you. As far as the pinouts it came from this site.

http://nesdev.com/NES%20EPROM%20Conversions.txt

AM27C128 is 16 KiB, and AM27C256 is 32 KiB. So let's make some lemonade.

With two AM27C128, you can make Thwaite, which has 16 KiB PRG ROM and 8 KiB CHR ROM. You'll have to patch it to add MMC3 init code.

With two AM27C256, you can make Adventures of Lolo 2, Burai Fighter, or To the Earth. All these are MMC3 games with 32K PRG ROM and 32K CHR ROM. You could also patch most CNROM games to use MMC3 bank switching and make those.

Thread moved to Reproduction board.

Why is it relevant that the guy is new to programming if this doesn't really even have to do with programming?

I assumed buying a "programmer" made me new to "programming"

I will change topic if I can.

Well, can you tell me what this does?



You can. Edit the first post on the page, and it will have a title over the box where you type that will display the title. You can then type where the title is to replace it.

Dude it's over. I meant New to programming eproms, chill-out. I already did edit title but some sites have a time limit that you can edit, that's why I said I would "try". I'm new to the site. The title is changed everyone is happy.

I wasn't meaning to offend you. Sorry. (I'm not being sarcastic. I was curious if you were actually trying to learn something like that.)

It's cool, I'm not offended I thought you were upset over the thread. I'm just trying to make repros of nes and snes games and whoah it is much more complicated than I initially thought. Going from knowing nothing to doing it. I have a friend who was helping me but it's been awhile since he did them.

I have barely touched the burning or programming of eproms yet. I purchased a GQ-4X True USB Willem ECU EPROM BIOS SPI Flash PIC AVR universal Programmer. I read mixed feelings about it, but it was only $100. I also purchased a cheap eraser just in case.

I ordered the wrong nes chips as I was pounding so much info at once lol. It's cool though. I need to place another order but I want to buy some snes chips but I want to make sure I have the right ones. I semi-goofed on the snes as well and thought those were 32 dip and most are 36 dip. I only bought 10 of those so they are still good for like dinosaur land. M27C801-100F1

The only 36 dip are tsop and requires a board. Buyic sells them mounted on a board but they are expensive. FUJITSU MBM29F033C-90PTN -TSOP Adapter III $12 each. I don't even know if you can buy the boards separate as I don't even know what they are called.

In this day and age I see no reason to any longer keep rare games when repros are so good. They look and play the same. I plan on selling my rare originals and making repros of them all. I still like the look of the games on a shelf so that's why I want to do it.

I looked at about 4 of my regular non-enhancement chip (except DSP 1) games and there were 23 pins, unless pins on the other side count as well, which in that case would be 46. I looked at 2 enhancement chip games I have, and there were 8 extra pins, 4 on each side, so there are 31, or 62 pins counting both sides. I actually don't have much, if not any, experience here so I won't really be able to help, unfortunately.

Just so you know though, we're prety civilized here. Most of us don't bite. (I did realize that I sounded like a bit of a jerk my first post here though.)

Why keep an authentic copy of Rare's Battletoads? Answer: That way when someone asks "Is this Battletoads?", you can pull out the cartridge and say "No, this is Battletoads." Or better yet: "Yes, and it's also Double Dragon."

Oh, you didn't mean these Rare games.


You can't spell "pirate" without an Arrr.

Now back to your regularly scheduled topic:


A DIP (dual in-line package) has two rows of pins separated by usually 0.6 inches, though narrow DIPs also exist. A typical mask ROM or EPROM sized for an NES game has 28 or 32 pins, which is 14 or 16 pins on each side.

A byte-addressed memory's pins comprise two power pins, one to three control pins (/CE, optional /OE or +CE, and /WE if it's writable), eight data pins, and the rest are address pins or NC (not connected internally). So you can take the and subtract 11 for PRG mask ROM, 12 for CHR mask ROM (with /OE) or AOROM PRG mask ROM (with +CE), or 13 for flash memory (with /OE and /WE) to estimate how many address lines there will be.

• A 28-pin PRG mask ROM can have up to 28 - 11 = 17 address lines, which means up to 2^17 = 128 KiB of data.
• A 28-pin CHR mask ROM can have up to 28 - 12 = 16 address lines, which means up to 2^16 = 64 KiB of data. This is why you would often see NES games with a 28-pin PRG ROM and a 32-pin CHR ROM.
• A 28-pin flash can have up to 28 - 13 = 15 address lines, which means up to 32 KiB.
• For a 32-pin memory, multiply sizes by 4.
• A 36-pin flash can have up to 36 - 13 = 23 address lines, which means up to 8 MiB.

A 36-pin flash is bigger than the biggest licensed Super NES game. Only a handful are bigger than even 4 MB. If a ROM has more than 36 pins, then either you miscounted or it's a 16-bit memory like they'd use on the Genesis. Some Super NES expansion chips that sit in front of the ROM use 16-bit ROM to help the cache work better, and some repros use 16-bit EPROMs because bigger ones may be easier to find as pulls or new old stock (NOS) than bigger 8-bit EPROMs.

Arrr matey, if you can't beat them join them.

Yes pirates have ruined this hobby for me. I don't even want to buy anything anymore as it is very hard to tell fake these days. You can spot a board easy by the eproms. However labels, manuals, and even boxes look just like originals these days.

I don't even want to get into sealed games. I plan on selling all my sealed games as well. The constant flooding of fakes has totally killed my desire to collect. I still like the massive shelf of games but somehow I feel I may just go everdrives for them all.

Even for my own personal use the labels will have reproduction on them, just because that's how it should be.

Well Tried to program a snes game and it failed. I got the gq-4x programmer. The disc came blank so I downloaded version 6.36 and installed it. I then downloaded the driver. I had to plug the programmer in and go to device manager and install driver that way.

I then checked eprom and it said it was blank. I selected file and then write. I just went with the settings it gave as I know nothing about speeds, or offsets and such. It failed at 47%.

Here are a few screenshots of what I got. I am not using an external power supply as I emailed mcumall and they said it was not needed.

Some more info I am trying to do a Return to dinosaur land. From this link:

http://nintendoage.com/forum/messagevie ... did=136815

I have the xdelta patch he provided. I used the no header and patched a Mario land rom using xdelta. the file has no ext. It is just a file 1024kb

It worked. I tried it w/ a diff chip and this time found the exact chip device m27c801 instead of generic 27c801 and I didn't have the quarts covered this time. So either the device media, chip itself, or covering the quarts was causing a failure? I will try the other chip again later.

Sweeet, just made my 1st reproduction cart. return to dinosaur land!

Can you swapbin nes roms? I was just making some snes repros and was noticing the same pins needs moved as when doing nes repros. It got me wondering if you can cut the snes rewiring down to 2 could the same be done with nes on the tlrom boards?

Swapbin works only for address-to-address and data-to-data swapping. NES mask-to-flash conversions are more likely to involve enable lines (/CE, /OE, /WE of the flash).

Sigh... Just tried making a repro. Put a TLROM-3, mmc3c mapper game onto a TLROM-2 w/ a sharp mmc3b as I read the sharp were compatible. Now it kills the power to my nes when I try to load it.

I looked it over and can't find any shorts at all. I'm about to pull the chips and toos the old ones back in.

Just put the old roms in and the game works.... so must not be compatible.

You shorted power to ground somewhere.

Well do you think I did it or was it incompatible? It's weird it works now after I put old roms in. Unless there was a stray piece of solder or something under the eproms I couldn't see and I found out after I took them back out?

I could try again if you think it will work?

found out what I did wrong ...ahhhhh. I soldered my prg in backwards and didn't even notice the 2nd time, only after using a donor I know works I really looked over everything.

Ok so can someone explain this to me? According to Callan Brown found here,
http://callanbrown.com/index.php/advanc ... production

and according to the pin outs written here:

http://nesdev.com/NES%20EPROM%20Conversions.txt

The wiring for:
TKROM & TSROM (mapper 4):
PRG socket:
Bend up pins 1, 2, 24, 30 and 31 (or cut tracks 2, 24, 30 and 31)
Solder pin 2 to hole 24 (A16)
Solder pin 24 to GND (OE)
Solder pin 30 to hole 1 (A17)
Solder pin 31 to hole 2 (A18)
CHR socket:
Bend up pins 1, 2, 22, 24, 30, 31 (or cut tracks 2, 22, 24 and 30)
Solder pin 2 to hole 24 (A16)
Solder pin 22 to hole 31 (CE or CHR /A13)
Solder pin 24 to hole 2 (OE or CHR /RD)
Solder pin 30 to hole 1 (A17)

Now at nesreproductions in his hall of shame he says the wiring for Mario 3 chaos is wrong?
http://www.nesreproductions.com/shame.html

I patched Mario 3 cc and in famiRoM it says this.

Super Mario Bros. 3 (USA).nes
iNES ver.: 1.0
platform: NES
mapper: 4
mirroring: Horizontal
prg size: 256KB (2mb)
chr size: 128KB (1mb)
prg ram: not specified
battery: no
trained: no
TV system: NTSC (default)
boards: (TxROM, MMC3, MMC6 [TKROM, TLROM, TSROM])
crc32:
file [163526D8]
prg [D3362F7F]
chr [A302BA6A]

So who is right? Also how do you determine which mapper to use or does it not matter? Like MMC3A MMC3B MMC3C.

The big behavior difference between MMC3A and MMC3C is what happens if the interval timer is set to fire an IRQ on every scanline. MMC3C can do it; MMC3A cannot. MMC3B S can; other MMC3B cannot. But the majority of MMC3 games don't care about MMC3A vs. MMC3C.

The "wrong wiring" stuff on nesreproductions mostly means that 4 Mbit (512 KiB) and 2 Mbit (256 KiB) EEPROMs need slight changes to the connections, and those changes may not have been made properly.

Well it requires a 27C020 for the prg and a 27C010 for the chr and according to what both refernces I posted show I would wire it exactly as the one that is shown in the hall of shame is wired. I don't understand what he is talking about.

In the link I provided form this forum it states:

http://nesdev.com/NES%20EPROM%20Conversions.txt

Using EPROMs in place of NES Mask ROMS:

27CXXX series EPROMs,
27C64, 27C128, 27C256, 27C512, 27C010, 27C020, 27C040

All of those are wired the same for prg and the same for chr

He wrote this:

"The program data memory chip (PRG) for this game requires a 27C020 EPROM. Yet this chip was wired as if it's a 27C040. "

"The character data memory chip (CHR) for this game requires a 27C010 EPROM. Yet this chip was wired as if it's a 27C020."

Everything I have read tells me he is wrong and those chips get wired the same exact way.

Well just tried to make Mario 3 Chaos Control and all I get is a black screen. I used Nintendo world cup as a donor. From reviewing the hall of shame cart it appears I may need to have w-ram? I am having a difficult time searching w-ram, not sure how to enter it in the search criteria in the database. I know a few carts that will work but seems like a waste to use a battery game.

In Famicon it says nothing about this game needing w-ram, how is one suppose to know this?

Super Mario Bros. 3 uses WRAM. (See the "WRAM 8 KB" in its NesCartDB entry.) If a game uses WRAM, hacks thereof probably use WRAM too. Appropriate donors for an MMC3 + WRAM + CHR ROM game are TKROM for battery and TSROM for no battery.

NM.

Ok so trying to understand the components on snes better.

I get mask roms and pinouts go here and there. What do they really mean? what is an a20 besides address line 20.

Like what is an 74LS00 when you look at the pinouts on that it just says like 7 is a ground.

Is there something I can read to learn what these diff chips do and how they relate to the other chips on board?