It is currently Sun Apr 30, 2017 7:51 am

All times are UTC - 7 hours





Post new topic Reply to topic  [ 35 posts ]  Go to page 1, 2, 3  Next
Author Message
PostPosted: Sat Jun 06, 2009 3:43 am 
Offline

Joined: Sun Feb 26, 2006 4:16 pm
Posts: 60
Hi,

Does anyone (kevtris? :)) have pinout info for the MMC3 clone chip marked AX5202P, which is used in some pirate cartridges? I have a couple of carts with that chip and the pinout would be helpful in figuring out how they work.

-- M


Top
 Profile  
 
 Post subject:
PostPosted: Sat Jun 06, 2009 12:23 pm 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3390
Location: Indianapolis
Here it is, on siudym's site. http://nintendoallstars.w.interia.pl/romlab/pmmc3.htm

According to kevtris' tests, it's 100% functionally compatible with the original MMC3. Though I wonder if it can help any with battery-backup.

BTW man, I remember you from the NESdev email list. That was a while back huh?


Top
 Profile  
 
 Post subject:
PostPosted: Tue Jun 16, 2009 6:47 am 
Offline

Joined: Sun Feb 26, 2006 4:16 pm
Posts: 60
Thanks for that! That page didn't show up in a Google search, probably because AX5202P doesn't appear in the text.

And yes, it has been a while... :)


Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 8:30 pm 
Offline
User avatar

Joined: Tue Dec 04, 2012 3:28 pm
Posts: 327
Location: Canada
Sorry to necro another old post! But i recently got my hands on about 10 of these AX5202p chips. I designed a basic TLROM board and tested with "Little Nemo: The Dream Master", and sadly only 4 of the chips work! The others either don't load at all, crash after selecting Start Game, or have completely messed up graphics. I've heard that some of these MMC3 clones can be a little hit and miss, but for half of a lot to not work is brutal odds.

So, my question is how or what would cause these chips not to work anymore, and in differing ways? As far as I can see these were new (well, new old stock anyways), so it can't have been from misuse. Or, is it possible that these AX5202p chips have different pinouts/functions?


Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 8:53 pm 
Offline

Joined: Sun Sep 19, 2004 11:12 pm
Posts: 18218
Location: NE Indiana, USA (NTSC)
I've read that among MMC3 features in these clones, the IRQ circuitry has the lowest yield. Try them with Holy Diver Batman; does anything but IRQ (third digit of result code) fail on them?


Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 9:29 pm 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3390
Location: Indianapolis
I had the same problem, out of the 10 that I tested, only 2 worked, some where partially working. Funniest one was where everything but IRQ worked, so SMB3 was playable without the status bar. I have some more tubes of them that weren't tested. It didn't look very promising, plus I don't have a board for it (was using a friends' board when we tried those 10), I never bothered to make one.

I don't know if we could ever know for sure, but my theory is that all the good chips were built into carts years ago, these were from a known bad batch that was set aside and never used, or were thrown out and someone pulled them from the trash. I have a hard time believing that that many defects could be normal, but I suppose that's possible too.


Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 10:45 pm 
Offline
User avatar

Joined: Wed Apr 07, 2010 1:14 am
Posts: 462
Location: Iran
Can you upload a picture of your chip?
I use this and never had any problem with them
It seems its date code is 1998


Attachments:
AX5202P.JPG
AX5202P.JPG [ 24.08 KiB | Viewed 2631 times ]
Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 10:56 pm 
Offline
User avatar

Joined: Tue Dec 04, 2012 3:28 pm
Posts: 327
Location: Canada
I have the exact same chips, even the date stamp is the same. Any idea what the issue is here?


Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 11:31 pm 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3390
Location: Indianapolis
Mine look similar, but the codes are different, 012823A 0016


Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 11:53 pm 
Offline
User avatar

Joined: Mon Apr 04, 2011 11:49 am
Posts: 1763
Location: WhereverIparkIt, USA
What do these things go for? Curious if it would be worthwhile to make a CPLD breakout board that was pin compatible with the AX5202P for dev use like this.

_________________
If you're gonna play the Game Boy, you gotta learn to play it right. -Kenny Rogers


Top
 Profile  
 
PostPosted: Wed Jun 25, 2014 11:57 pm 
Offline
User avatar

Joined: Wed Apr 07, 2010 1:14 am
Posts: 462
Location: Iran
@ infiniteneslives
Using these clones will salvage the remaining original NES/Famicom cartridges :mrgreen:


Top
 Profile  
 
PostPosted: Thu Jun 26, 2014 12:10 am 
Offline
User avatar

Joined: Tue Dec 04, 2012 3:28 pm
Posts: 327
Location: Canada
Not necessarily... they are still available from some online places, but if they only half-work then whats the point?

I've attached a couple pics of what my issues are. One is a working chip, the other 2 not so much.


Attachments:
File comment: bad chip #2
2014-06-26 00.42.58.jpg
2014-06-26 00.42.58.jpg [ 200.36 KiB | Viewed 2619 times ]
File comment: bad chip #1
2014-06-26 00.26.51.jpg
2014-06-26 00.26.51.jpg [ 125.67 KiB | Viewed 2619 times ]
File comment: Working chip
2014-06-26 00.26.26.jpg
2014-06-26 00.26.26.jpg [ 181.08 KiB | Viewed 2619 times ]
Top
 Profile  
 
PostPosted: Thu Jun 26, 2014 1:35 am 
Offline
User avatar

Joined: Wed Apr 07, 2010 1:14 am
Posts: 462
Location: Iran
From the pictures I say they are defected for sure
Were they used when you bought them?
You need to adjust the pins (bend a little manually) of an unused chip to insert it into the IC socket, this is a sign of a new chip
Also these chips are very sensitive to static electricity and they must carried or shipped inside of a special tube

ps : very nice controller you have, I have the same thing and works perfect, nes controller with snes style


Top
 Profile  
 
PostPosted: Thu Jun 26, 2014 9:30 am 
Offline
User avatar

Joined: Tue Dec 04, 2012 3:28 pm
Posts: 327
Location: Canada
Yeah all of the pins had to be bent slightly to get them into my socket. They came in a tube in a static-free bag, so I'm not sure what could have happened there... I spoke with the place I bought them from and they told me "they can't be faulty, the manufacturer has said they were new and unused", but they sure appear faulty to me...

BTW, the ones that do that blue garbled screen also get very hot after a minute, and have a scrolling humbar vertically. Almost what you'd expect if you reversed VCC and GND or something, but the chip was inserted correctly.


Top
 Profile  
 
PostPosted: Thu Jun 26, 2014 1:30 pm 
Offline
User avatar

Joined: Wed Jul 13, 2011 6:51 am
Posts: 382
Location: Brasilia, Brazil
It's possible they're mis-labeled.

They could be the VRC4 clone or the alternate MMC3 type. I know of at least two different pirate MMC3 pinouts.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 35 posts ]  Go to page 1, 2, 3  Next

All times are UTC - 7 hours


Who is online

Users browsing this forum: No registered users and 9 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group