anybody know the pinout for the PRG and CHR for a MMC2? i wanted to make a repro and couldnt find anything about this board
MMC2 (P*ROM, iNES #9) was used for only one boxing game, which existed in a couple revisions. Are you trying to convert a board from the revision with Mike Tyson to the revision with Mr. Dream or vice versa?
no, i am trying to makee a repro of a punchout hack
it looks like there are only 28 pins in the board for the prg:
http://bootgod.dyndns.org:7777/image.php?ImageID=8169
would it be possible to wire up a 32 pin eprom here?
coinheaven wrote:
would it be possible to wire up a 32 pin eprom here?
Sure, as long as you wire everything correctly. I had to do this on
my UOROM devcart. Notice that the socket is longer than the board.
Use the pinouts of 28-pin mask ROMs as a reference. They can be found on the main NESDEV page. Compare that to the datasheet of your EPROM and you're all set. The final wiring may look like that in my UOROM cart, but not exactly, because I used a Flash ROM.
ok, ill give it a shot, i have a punchout cart coming next week. ive made UNROM's before, so ill try to wire it like that. should i wire the CHR like an MMC3 or MMC1?
Quote:
should i wire the CHR like an MMC3 or MMC1?
I bet it is exactly identical in all cases.
accoring to the eprom conversions, they are very close except for one wire:
MMC1:
CHR socket:
Bend up pins 1, 2, 22, 24, 30 and 31 (or cut tracks)
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)
MMC3
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)
it wont be a problem though, i can try both and see which one works
Both are exactly the same exept that there is no A17 on the MMC1 because the maximum CHR size is 128kb.
I bet the maximum CHR size is also 128kb with MMC2, so it's the same as MMC1 and almost the same as MMC3.
ahh, that makes sense, i always wondered why that was.
so i got around to trying to make this, i think the PRG is wired wrong though. I bent up pins 1,2,24,31,32. I wired hole 24 to pin 2, pin 24 to pin 16 and then pin 1 to pin 30,31,32. this is how i normally wire up an UNROM. anybody know what could be wrong?
all i can think of is that the rom pinout is different than this:
http://nesdev.com/NES%20ROM%20Pinouts.txt
if so, how could you tell? meaning, how were these figured out in the first place?
Probably lots of multimetering and hours behind the osciloscope.
Jeroen wrote:
Probably lots of multimetering and hours behind the osciloscope.
yikes
if the hack is just a graphics change, could you just switch out the CHR chip?
coinheaven wrote:
if the hack is just a graphics change, could you just switch out the CHR chip?
If only the tiles were changed, yes. But most (good) graphic hacks include palette changes, tile mapping changes and so on, that require the PRG to be swapped too.
ok, that makes sense. i was looking at your UOROM repro:
http://nesdev.com/bbs/viewtopi ... ight=uorom
it looks like from the pictures you wired it like this:
bent up pins 1,2,24,31,32
wired pin 1 to pin 16
wired pin 24 to pin 22
wired pin 2 to hole 24
wired pin 31 and pin 32 to pin 30
can you confirm if this is correct?
coinheaven wrote:
it looks like from the pictures you wired it like this:
bent up pins 1,2,24,31,32
wired pin 1 to pin 16
wired pin 24 to pin 22
wired pin 2 to hole 24
wired pin 31 and pin 32 to pin 30
can you confirm if this is correct?
OK, I just got the cart. Yup, this is all correct.
The only thing missing is pin 30 (A17), which was also bent to be connected to the mapping hardware. I don't know what the size of the PRG-ROM of your game is, but whatever address lines are not used should be connected to GND (like I did with pin 1).
Also, keep in mind that this cart was made for an AT29C040 Flash ROM, as you can see in the pictures. If your chip is different, just look at the datasheets of both chips to see how they differ from each other and make the proper adjustments.
tokumaru wrote:
coinheaven wrote:
it looks like from the pictures you wired it like this:
bent up pins 1,2,24,31,32
wired pin 1 to pin 16
wired pin 24 to pin 22
wired pin 2 to hole 24
wired pin 31 and pin 32 to pin 30
can you confirm if this is correct?
OK, I just got the cart. Yup, this is all correct.
The only thing missing is pin 30 (A17), which was also bent to be connected to the mapping hardware. I don't know what the size of the PRG-ROM of your game is, but whatever address lines are not used should be connected to GND (like I did with pin 1).
Also, keep in mind that this cart was made for an AT29C040 Flash ROM, as you can see in the pictures. If your chip is different, just look at the datasheets of both chips to see how they differ from each other and make the proper adjustments.
the prg is 128 kb, so i am using a 27c010 eprom chip. it looks like they are very similar, except for pins 1, 30,31,32:
http://www.datasheetcatalog.com/datashe ... C040.shtml
EPROM 27C010/27C1001 128KBytes (32pin):
---_---
VPP - |01 32| - VCC
A16 - |02 31| - PGM
A15 - |03 30| - NC
A12 - |04 29| - A14
A7 - |05 28| - A13
A6 - |06 27| - A8
A5 - |07 26| - A9
A4 - |08 25| - A11
A3 - |09 24| - OE
A2 - |10 23| - A10
A1 - |11 22| - CE
A0 - |12 21| - D7
D0 - |13 20| - D6
D1 - |14 19| - D5
D2 - |15 18| - D4
GND - |16 17| - D3
-------
what is PGM, NC, OE and CE? I know what they stand for (No connect, Output enable, Chip enable, but dont understand them when it comes to rewiring. like why do you wire A16 to OE?
coinheaven wrote:
what is PGM, NC, OE and CE? I know what they stand for (No connect, Output enable, Chip enable, but dont understand them when it comes to rewiring. like why do you wire A16 to OE?
PGM is used for programming the chip, it has no use in a dev cart. I'm not sure if it should be connected to VCC or to GND (I've never used EPROMs), maybe someone can clear this up.
Output Enable and Chip Enable are used by the NES to activate and deactivate the chip depending on which parts of the memory are being accessed. The chip should only be active when the address is between $8000 and $FFFF. When other addresses are accessed, other chips are enabled instead (such as WRAM when $6000-$7FFF is accessed). Only one chip can output data at a time, or else the resulting data would be useless (bus conflicts).
Note that I DIDN'T wire A16 to OE. Take a look at the
pinouts of the Nintendo ROMs and you'll see what each hole is for. Hole 24 is clearly A16. That is the whole purpose of bending pins up: avoiding them to get in contact with the wrong holes, while the wires connect them to the correct holes on the other side of the board.
yea, your right, i was looking at the eprom pinout. so i think i was wiring the PRG correctly if the MMC2 has the normal pinout. but it is still not working. it doesnt seem logical that this board would have different pinouts, but i guess anything is possible. no clue what to do to get this working
so i obtained a PEEOROM board and was able to get the punchout hack to boot up, but still has scrambled graphics. so it seems this board uses the normal PRG pinout but a different CHR pinout. anyboy have any suggestions on how to wire the CHR? i wired it like a MMC1