Custom Cartridges / ROM Hacks

[Family Computer]

How possible is it to make a really simple custom game for most of the cartridge based systems?

I haven't done too much research about it but I have definitely seen it done for some Atari systems, NES, and Genesis.

Are some systems still not possible to make a custom cartridge with a donor game / eprom burner?

[Steve W]

Not that I know of. I've heard of things like multicarts available for systems as odd as the Emerson Arcadia 2001. The main problem is having to learn how to program one of those old systems, then getting the correct type of circuitboard and reusable ROM for it. Some machines, most notably the Atari 7800 and Atari Jaguar, had encryption keys that would lock out non-authorized cartridges, but those have been cracked in the past few years. There's not much stopping anyone from making homebrews for cart based systems, other than learning how to write code for those consoles.

[Family Computer]

Well, the good thing is I don't want to program an entire game. I know that would be insanely hard for most systems even for a decent programmer (I am no programmer).

The way I want to use it is for an audio visual project that I've been thinking about for many years. I would basically only need to get a custom intro / title screen going on each system (thinking famicom/superfamicom/megadrive/n64/gameboy).

It would be similar to a pretty basic demo scene type of thing but running on the real hardware. At very least I would need to be able to get a static title screen running, but hopefully I could get slightly more complex than this.

Anyway, it seems as if it is possible on a system, this type of thing would be relatively easy to implement.

I also don't want to use flash carts at least for the final product. I am sure a flashcart would be good for testing along the way however.

[Rev. Link]

What about repros? I've seen plenty of places that sell repro carts for NES and SNES. How difficult is it to find a translated ROM of, say, Holy Diver and get it into cart form?

[Family Computer]

What about repros? I've seen plenty of places that sell repro carts for NES and SNES. How difficult is it to find a translated ROM of, say, Holy Diver and get it into cart form?

That's basically the first part of my inquiry.

1) Which systems is it relatively easy to make a custom cartridge for (and which is it impossible for)?

2) How hard is it to create something like a basic intro/title screen on said systems?

[badinsults]

For most systems, it shouldn't be too hard to find a repro, as long as you can get a proper donor cart. It is as simple as removing the mask rom from the donor and wiring on EPROMs. However, it is far easier (and cheaper) to buy a flash cart. There are flash carts for most popular systems, and they can generally play 90-95% of the library. Check out the Everdrive series (http://krikzz.com/) by KRIKzz, or RetroUSB's Powerpak (http://www.retrousb.com/index.php?cPath=24).

On your other question (modifying the game title screen), this is far more complex and requires hacking. I suggest visiting romhacking.net to find out more, though it requires a lot of dedication and knowledge of low level programming.

[Parodius Duh!]

heres an incredibly easy hack you can do:

http://133fsb.wordpress.com/2009/11/21/dream-mary-on-a-budget/