Coolboy cart programmer

[lidnariq]

It seems more likely to me that that is the MMC3's PRG RAM +CE output instead of A13...

[BennVenn]

I think you're right in that the board was intended to control 8kbytes of SRAM, not 32. Still, a 32k IC is a direct drop in replacement which is handy.

[BennVenn]

The 72 pin coolboy games are no longer 60 pin with adaptors. A whole new board. Luckily the gold fingers are longer than they need to be so I could solder onto those.

Interesting the date stamp on the mmc is 18nov2015.

[getafixx]

You know, for a chinese multicart board that looks really well assembled...

What kind of CPLD is on there for the mapper? Looks like an Altera something-something.

[BennVenn]

Yeah, gold plated and even washed of all flux after soldering. They've really improved from the dodgey nickle plated version 1 boards.

The mapper is a custom ASIC. 'SMD132' I've not found any data on this chip except for the reverse engineering attemps by clusterr and myself.

[Memblers]

That's interesting, I wonder exactly what finish they've used on their different edge connectors. If the gold on the edge pins looks the same as the IC pads, then I'd think it'd be immersion gold (ENIG). That costs almost nothing compared to electrolytic gold (hard gold), I wonder how well it would hold up with repeated use in a tight connector though. IPC specs say ENIG on a connector is rated for something like 5 insertion cycles, maybe not so bad in a front-loader since it takes less lower force. Hm, I might have to buy one of these and run it through a Game Genie a bunch of times and see what happens. Would be nice if I could bring down the price of the boards I've been making without making it too crappy.

[BennVenn]

There is no sign of electroplating (small traces running off the fingers to ensure uniform potential when in the bath) so I'd say its ENIG.

No bevel on the edge either unlike their earlier boards. So they cut costs there

[tepples]

I get the idea from the use of the word "early" in the Wikipedia article that ENIG processes have improved. Is that the case? There's also ENEPIG that puts palladium between the nickel and gold. Is that any better?

[Memblers]

I have been very curious about ENEPIG, unfortunately the only source I've seen for the IPC-4556 doc is like $300 for a paper copy.. that's a bit much for my hobbyist curiosity, heheh. I wouldn't suppose anyone reading this thread has access to that, but I'd love to know just what it says for it's durability as a connector finish. I've seen articles mention that it's suitable for low-insertion-force and ZIF connections, but no details beyond that. I suppose I can ask my board manufacturer, I don't think the one I use offers that finish but it's probably worth asking around.

[BennVenn]

I read a thread over at eevblog that in the last year or two there have been big changes to what chemicals can be used for the gold depositing process in China. Because of this, prices in general have increased especially with plated boards.

I can confirm the nickle plating on the 60pin boards is incredibly tough and a pain to solder to! It took a lot of effort to cut a pad. Far more sturdy than gold plating. Is the difficulty to solder the only reason it isn't more common?

[The_YongGrand]

Hello BennVenn,

I like your cheap Famicom cart mod, any rough schematics you can share here?

I can get these carts cheap from Taobao there, and I will do the rest of the programmming.

If I'm not mistaken - you only connect the cart's CPU data and the address lines (and the Write line on the flash chip) to the microcontroller board?

[BennVenn]

That's right. Schematics are nothing special, standard data and address bus type stuff. Prg bus only

Any cpu will do the interfacing to the PC though I'm keeping my source/bin private. You could very easily connect it to an arduino for example.

Google the flash ic and you'll get the datasheet and flash instructions.

Last piece of the puzzle is the mmc but thats pretty well documented too.

[The_YongGrand]

That's right. Schematics are nothing special, standard data and address bus type stuff. Prg bus only

Any cpu will do the interfacing to the PC though I'm keeping my source/bin private. You could very easily connect it to an arduino for example.

Google the flash ic and you'll get the datasheet and flash instructions.

Last piece of the puzzle is the mmc but thats pretty well documented too.

Thanks BennVenn for the info. I'll check the datasheet for that particular flash chip. Since I'm in SE Asia, it's mostly Famicom, so the cart fits on a Famiclone.

I can do the flash programming by myself there - I have these tools. And of course, I assume it's possible for me to put one (1) game inside for a quick test?

Edit: Is your cart looking like this? http://www.aliexpress.com/item/No-repea ... 206.2ihLJX

[BennVenn]

You could use that cart though it doesnt have wram or very large chr ram. Get the kirby cart.

You will need to write a bootloader if your rom uses chr rom.

I have a few I built for generic roms. 32/32k 32k/128k etc.. ill post them here

[The_YongGrand]

You could use that cart though it doesnt have wram or very large chr ram. Get the kirby cart.

You will need to write a bootloader if your rom uses chr rom.

I have a few I built for generic roms. 32/32k 32k/128k etc.. ill post them here

Thanks for the info. I wanted to write my own FC game and play it on a Famiclone, but Everdrive N8 is too expensive for me. I'll try to use the another version of the cart with the battery (you mentioned the Kirby, probably it's the one).

Also, I guess that you already have a memory map of these cart laid out, or still in progress? I'll test my game in the emulator first, then I'll get the actual hardware once I'm done with them.