Making repoduction NES/SNES carts?

Hm. It might be a stupid questions after all the hassel, and by the way thanks to TriMesh for counting all posibilitys down, but: How is it about not eraseable Memory devices?
Most of the ppl that do ROM replacement do that on a certain card and not only few of them seems to have a special game in mind that they want to play/to patch. So beeing able to flash/reprogramm the entire card dont alwas is a must/have.

I was looking around for some seemable devices that accept a one time write cycle. But since im a noob with only some weeks exp in this topic I failed hillarious to find something but EEPROM and Flash Devices with the needed specs.

 

Eproms are small capacity for the most part and relatively expensive to new and current chips.

Also eproms tend to be DIP which are larger physically

 

I have a question in regards to zelda AST. Does anyone know here how the memory banks work? There isen't much information about this cart out there and this is a tougher one. I know how to do it with 4x 29f032 but i'd be nice to only use 2 of them. I know they use 74ls139 and 74ls393. I seen a wiring diagram before but it was only for 4.

 

Does anyone know of an equivalent SRAM chip that is available today (SMD or Through Hole) or one that will work for most games that have SRAM? and what is a way to get around the CIC chip or whatever security the system checks for? I'm basically looking into building my own board from scratch and would like to have some idea of what parts I can use, oh and I will be definitely looking into larger and more readily available and cheaper Flash Memory. Any input would be helpful,thanks.

 

I think a SuperCIC can be used in "key" mode so you can use it on a cartridge. Cartridges like SD2SNES and PowerPak use that.

 

Can someone tell me, how to use japanese cartridges for making a reprocard for a pal console? I´ve read that you have to swap the region lockout chip on the game cartdridge? Is this correct? Are there any tutorials?

 

I'll show you my lazy method. First step is disabling the original maskrom(s). This can be done by either removing them (no kidding), or by permanently setting their /OE high. The +5V is placed conveniently right next to it, so instead of desoldering the big dip chips I just cut the /OE leg and bend it over:

This takes significantly less time than desoldering, has no risk of lifting pads, and you can use the legs that stick through the other side of the board instead of a pinheader that you would normally solder onto the adapter. If you have a game with multiple ROMs, just do so for all of them. Not the SRAM though!

Next is installing the adapter. Please don't use buyicnow adapters. They're incredibly bad. Design your own (it's super simple) or buy them from someone who's not looking to squeeze your wallet. I know some websites are, not calling names, but $3 for just a superfx adapter is at least 300% too much. Anyway, I guess a picture says more than words:


If your donor sports a 32mbit ROM you're in luck. Just one ROM to disable and both A20 and A21 are available right where you want them. This isn't always the case. At least on MAD-1 boards, you can instead just grab /OE and A21 there. Sometimes you also need A20 from the edge connector. It's not too bad if the adapter pcb accounts for it:


Finally, PAL games require a D413 CIC chip, or a supercic/snes-cic/etc. The latter is easier to buy in bulk from off-the-shelf components. You can already see I installed one in the two pictures above. You will also have to cut the original CIC's data and reset lines.

So that's another 5 second job

All in all, including cleaning the contacts and prepping the board, replacing the battery and testing everything, you really don't need more than 30 minutes per card.

 

Thanks for comprehensive answer!
So to put it in a nutshell I have to:
- remove or disable the original maskroms
- the superfx adapter on A20 and A21
- install the D413 CIC chip.
Is this right? Where do I have to place the superfx adapter and the d413 cic chip?

 

Those pictures aren't for a superfx board at all.
I install the adapter board on the back of the maskrom and the supercic board on the back of the original cic.