Please, help me with a MMC3 Dev Cart

[Whipon]

I need help setting up a MMC3 Dev Cart:
I took an Astianax cart. Desoldered the 2 eeproms (27C1000) and then soldered two DIL 32 sockets.
But I can't make the game run. I'm triying to play Captain Tsubasa Vol 2 with no luck. Tried connecting A17 and A18 in the two sockets to high with no success, then to low with no success. What I'm doing wrong?. Its because Astianax has 128 kb prg and 128 kb chr and Captain Tsubasa 2 has 256 kb prg and 128 kb chr?. How can I setup these pins?. All I managed to do where crazy statics pixels on the screen everytime I press reset.
Any help would be much apreciatted n___n.

[tokumaru]

I took an Astianax cart. Desoldered the 2 eeproms (27C1000)

What do you mean "desoldered the EEPROMs"? The chips inside Nintendo manufactured NES carts are not EEPROMs, They are Mask ROMs, with a pinout unlike regular EPROMs, EEPROMs or FlashROMs. The only types of carts you can get away with simply soldering sockets are NROM and CNROM, the boards used in first generation NES games (limited to 32KB of PRG ROM and 32KB of CHR ROM). Anything else requires a certain level of rewiring.

The main NESDEV page has documents describing the pinouts of the Mask ROMs. Just compare those to the chips you wanna replace them with and reroute any pins that don't match to the correct holes on the board.

On all of the MMC3 boards I checked, even when the games use less than the maximum allowed sizes for each chip, the holes on the board are still correctly connected to the higher address lines on the MMC3 chip, so that's probably not a problem.

[Whipon]

They are 2 chips 32 pins each with the 27C1000 description printed. Is a pirate famicom Astianax cart. Tha mapper is apparently under an epoxy black cover.
I searched alldatasheet.com for 27C1000 and downloaded the data sheet and it says its a CMOS EPROM (one time programmable). I've found these chips in severall of my carts, or UVEPROMS, and 28 pins MASK ROMS also. In this case there is a 27C1000 that is a CMOS EPROM. I compared the pinout with my AM29F040B and the only difference is that pin 1 in the 27C1000 is the VPP and is A18 in the AM29F040B. Also pin 30 is described as Not Connected and in the AM29F040B is A17.
Maybe I must try in a better cart?. I have an 8 Eyes cart with two 27C010 UV EPROMS and it has a MMC3 mapper wich is a 40 pins dip chip and also has a 14 pin LS32.
Thanks.
Whipon.

[Whipon]

I desoldered the two 27C010 from the 8 Eyes cart. Then compared the pinouts with my 29F040 and the differences are the same than with the 27C1000. (pin 1 and pin and pin 30). Both pins are connected to +5V so I soldered the 32 pin sockets in the same way.
I tried running Alien 3, Little Samson and River City Ramson with no luck. If I put the 8 Eyes 27C010 them work fine in both carts. But when I put my eeproms them doesn't work.
I'm separating the PRG and the CHR through an hex editor. For example River City Ramson (128 kb PRG and 128 kb CHR). First I delete the first 16 bytes, then I select a block from 0 through the hex offset 20000. I save that to RCR PRG.bin. Then I save the remaining info as RCR CHR.bin. Then I program them to both of my 29F040. I can't understand what I'm doing wrong.
Any suggestions?.

[tokumaru]

Ah, so it's a pirate... well, I really can't help you then. I can tell you that you shouldn't trust pirate carts when making devcarts though, because the mapper may not function like the original.

[Whipon]

Thanks again for the info.
I don't own any original, surelly all my carts are pirate ones. I'm surprised, because both carts work well with the UVEPROMS of the 8 Eyes cart. So it can be coincidence that two MMC3 games had the same buggie mapper hacked in them. (because in the Astianax cart it has the mapper covered with epoxy, and in the 8 Eyes the mapper is a 40 pin dip).
I've found this web with some EEPROM modifications:
http://nintendoallstars.w.interia.pl/romlab/nesmod.htm
Maybe I can apply these pinouts to make the cart work?.

[Whipon]

Well, I flashed 8 Eyes to the 29F040s. The game works, but with corrupted graphics. I forgot to tell you that the same happens with the original 27C010 that were in the cart. When I insert them I get corrupted graphics in both carts. So it seems the mapper is corrupted or this thing has a very rare chip.
Anyway, It was fun. Now I'll need to look for a original cart with mmc3 mapper. Do you know where I can find a 72 to 60 pin converter to play NES games on a Famicom?. I searched ebay but couldn't find one.

[Roth]

I got my hands on one when I bought a Handi-Fami 8, but I can't seem to find anymore of those on eBay. If you can't find a converter, you could try asking around various gaming forums to see if anyone has one of those fami-clones, and if they would trade/sell it to you. I'd rather not part with mine in case I need it for something in the future, but maybe that will help you out some. Good luck!

[Whipon]

I couldn't wait anymore. I searched in the local e-shops here in Argentina and found and original NES frontloader, two adaptors, one to play famicom games on a NES and another to add PAL/NTSC compatibility, and a original Super Mario Bross 3 cartridge. I bought all of these items for U$S 51 and must go for them tomorrow.
The story is very different with an original NES cart, right?. I mean, Can I do the devcart with it without the problems I found with the pirate Famicom carts?.

[tepples]

There's still a bit of rewiring to add *EPROM sockets to an NES cart board, but at least this rewiring is a known quantity.

SMB3's board uses CHR ROM, so you'll need a different board if you also want to develop with CHR RAM.

[Whipon]

At the moment, I only need a board with CHR ROM. SMB3 uses mask roms?. I've successfully rewired an unrom cart with a 28 pin Mask ROM in it, it wasn't difficult.

[sdm]

CONNECT 29F040 flash /WE and /OE pins together!!!

[Whipon]

So, you mean connect the two pins to ground or to +5V?. I tested some games with the Famicom to NES converter and they worked well. Actually I'm triying to fix my UNROM devcart, because the height of the sockets doesnt let the cart to enter my frontloader.
Tonight I opened the case of this baby and was filled with dirt and insect parts. What a mess. Also, the two RF shields and some parts of the motherboard was filled with a slippery substance, like oil. I had a lot of work.
I removed the pin 4 of the lockout chip accidentally, but I readed its not absolute necessary to ground it. I can play Yoshi PAL without the adaptor!. Also I maked the blue led mod.
Anyone know of a good shop who will ship to Argentina a new Cartdridge Connector?. I'm geting lots of green screens of death u_u.

[Jeroen]

No need to ground that sucker. It already does internally.

[tokumaru]

Anyone know of a good shop who will ship to Argentina a new Cartdridge Connector?. I'm geting lots of green screens of death u_u.

A while ago, you could find lots of them on eBay. I got one that was shipped to Brazil with no problems, it should be the same with Argentina. These are not exactly like the original connectors though, you even have to leave a few screws out for it to fit. You no longer need to push the cart down (don't even know if it'd be possible), just inserting the cart works 95% of the time, if the cart is in good condition.