how to use different ics when making a cartridge?

[marcao_cfh]

Hello everybody. How's going?

I mainly play using flashcarts, but I want to make my own cartridges at least once. Just for the sake of making them. To be more specific, I want to make one Game Boy cartridge and one SNES cartridge, maybe one NES cartridge too once I get a donor. Already got one donor for the other two systems.

I have good skills on electronics, soldering won't be a issue. And I have acess to a good burner, I mean, I have a friend that works in a repair shop that have a SuperPro. The think is I don't have too much theoretical knowledge on electronics, and zero knowledge on programming. But I found a great 'diy snes cartridge for dummies' I can follow, including how to check for what games can be burned into the donor cartridge, and also a kinda good tutorial for game boy cartridges, but...

The thing is I can get the ICs the tutorials uses. I live in a small city in a 3rd world country that doesn't have electronic parts stores, and the city near me have stores but don't have those ICs. And while I could buy overseas, my country have a import fee that forces me to thing twice (or more times) before importing something. So I'd like to try to use what I already have here.

I have a 29F400 and a 29LV160 IC, one of each, and I know they can be used to make snes and game boy cartridges since I already found some examples online. I'm already aware on the 29LV160 voltage issue, but I'd like to at least give it a try and then once I get the cartridge working I can buy the correct voltage IC.

So, since I don't have theoretical knowledge, my question is how can I use those EEPROMS? I didn't found a guide on how to use them, just reports of people using them. If somebody can give me a quick guide on how to check for which pin goes where, and what other mods I need to to do use those EEPROMs, or any tip, I would be glad.

Thanks in advance!

[Joe]

The "easy" way is to use the ROM in word mode: duplicate each byte so when you burn the ROM each word contains two of the same byte. Connect RESET# and BYTE# to 5V, leave RY/BY# and half of the data pins unconnected, and connect everything else according to the guide. You waste half the capacity of the ROM this way, but you can pick which half of the data pins to connect.

If you want to use the full capacity of the ROM, you need to use byte mode. Depending on the programmer you're using, you may need to swap the bytes before you burn the ROM. In byte mode, the address pins are numbered starting at -1 instead of 0, so you have to connect the A-1 pin to A0 on the board, the A0 pin to A1 on the board, and so on. Connect RESET# to 5V, connect BYTE# to ground, leave RY/BY# and D8-D14 unconnected, and connect everything else according to the guide.

[marcao_cfh]

Sorry for the late reply. I didn't got a notification my post was approved and got a reply.

First of all, thanks for replying. As I don't have too much teorethical knowledge, I didn't understood most of it lol. But it's a start, and I noticed I need to study a bit more before I understand how to properly do it.

Do you have any links to guides or something that can help me?

[Joe]

Do you have any links to guides or something that can help me?

This guide has a section that explains matching pins on your new ROM to holes where you removed the old ROM. Maybe that will help? Pinouts for your ROMs are listed in their datasheets.

[hidden0]

The easier you can for SNES m27c801 eeproms With a Donor board any 1MB game there are plenty of tutorials out there.
for Gameboys you can get a Repro pcb from mousebit labs and follow their tutorials.