SLROM Clone PCB + Schematic

FARID · Post by **FARID** » Sat Sep 10, 2011 12:47 am

I want to know is there anything out there? If not I start my own work.

FARID · Post by **FARID** » Sun Sep 11, 2011 12:14 pm

Please help me to solve the problem.

I found a KS5361. I can confirm that it is a clone of MMC1.

And here is the pinout :

And here is SLROM Schematic :

I can run the game but it crashes or rests randomly. I tested with two different games and the result is the same. I have two clones of MMC1 chip which their part number erased. I used them with no good result neither. But I feel that KS5361 tends to crash and resets more and sooner. How can I solve it?

Who can identify these capacitors for me?

Bregalad · Post by **Bregalad** » Sun Sep 11, 2011 12:29 pm

I don't know why the game would randomly crash or reset, but maybe not all MMC1 functionalities are implemented on the clone chip ?

The capacitors are used to filter the power supply from noise. I think it's required you put a couple of them on the board, as close as possible to the ROM/mapper chip's supply.

Post by **lidnariq** » Sun Sep 11, 2011 1:48 pm

FARID wrote:Who can identify these capacitors for me?

I think those pink-bodied things are the same throughout the production line; the capacitors I have on this random CNROM board look the same and are brown black orange silver brown, or 10*10^3 pF = 10nF ±10% 100ppm/Kelvin (wikipedia).

infiniteneslives · Post by **infiniteneslives** » Sun Sep 11, 2011 2:39 pm

The bigger cap is probably 22uF. If not something in that range 10-47 uF should be fine. But I doubt thats the reason you keep getting crash/reset issues. It's worth tacking them on there because they should be there.

Do you have any games that originally had one of those MMC1 clone in them? Do they work well in that game (assuming you have one)?

I would try to test the chips out in a game that originally used a clone MMC1. Then try running a the game that had the official MMC1.

One other thought. Are you CERTAIN that the clone has the same pinout as the official MMC1? It wouldn't surprise me if they were different. I'd actually assume they are different until you prove otherwise.

FARID · Post by **FARID** » Sun Sep 11, 2011 10:11 pm

I have this clone :

Chip 'n Dale Rescue Rangers (It seems it is a pirate version from Japanese version labeled Grand Combat)

Information of Dumped ROM by Nestopia :
File: DUMP.nes
Soft-patched: No
CRC: 86E77C60
SHA-1: B6AEB1B45313B4AF4899EB479DBFDA5B37D77461
System: Famicom
Board: SKROM, Mapper 1
PRG-ROM: 128k
CHR-ROM: 128k
W-RAM: 8k
Solder Pad: H:1 V:0
Battery: No
Dump: Unknown

Front

Back

infiniteneslives · Post by **infiniteneslives** » Sun Sep 11, 2011 10:49 pm

Have you tried playing that chip and dales with your "new" clones?

I assume you've intentionally desoldered the bottoms of the roms and aren't trying to play it as you have it pictured. Because it definetley won't work as it looks in the picture.

Also, Have you thought about putting something over your EPROM windows to block light from corrupting your roms?? I would double check those Roms to ensure you haven't lost data due to natural light and put some masking tape over those puppies!

FARID · Post by **FARID** » Sun Sep 11, 2011 11:55 pm

OK. Thanks guys, I have solved the problem.

It was really interesting.
I am using AM29F040 because I have plenty of them in my stock. It seems CHR doesn't care about its A17 and A18 floating but PRG doesn't like it at all!

I had filled both of them with fourfold data of 128KB so I didn't worry about A17 and A18 being floating!

How to solve it :

Pin 30 of PRG (A17) --> Pin 4 of KS5361
Pin 1 of PRG (A18) --> 5V

By the way, the games run ok without using any capacitor. So they are unnecessary!

infiniteneslives · Post by **infiniteneslives** » Sun Sep 11, 2011 11:59 pm

FARID wrote:It seems CHR doesn't care about its A17 and A18 floating but PRG doesn't like it at all!

Ooo yeah, leaving inputs of ANY chip floating isn't a good idea. It's hard to predict what it may cause and it's usually sporadic causing all kinds of craziness which is what you kind of saw.