Can a single person develop a Sega Genesis emulator?

Question

Someone told me that Sega Genesis emulation can not be done by one person, not even for many years. Why is this? Small indie teams and open source projects make emus for free, and there's a video on YouTube of a guy writing a NES emulator in C++ in less than a few hours. Why can't one make a Sega Genesis emulator?

If you can read documentation on the hardware, which is widely available, and you can mimic a Motorola 68k plus the Zilog co-processor, what could possibly take so long?

Answer 1

Someone told me that Sega Genesis emulation can not be done by one person, not even for many years ... why is this?

Emulation of classic video game system is extremely difficult if your goal is 100% accurate emulation that plays all games without glitches or other errors.

Small indie teams and open source projects make emus free, and there's a vid on youtube of a guuy writing a NES emulator in C++ in less than a few hours.

The NES is one of the most reverse engineered and hacker-documented proprietary platforms ever. Information about it is readily available pretty much only thanks to the freely available work of hundreds, if not more. Roll back to 1994, 1995 when most of this started and it's a different story.

I guarantee you that such guy will NOT have all NES mappers emulated properly in a few hours. There are hundreds of those, each needing to be uniquely emulated in addition to the NES hardware.

Why can't on make a Sega Genesis emulator? I mean heres how I look at it

if you can read documentation on the hardware whcih is widely available

With many classic video game systems documentation was NOT available (Sega, Nintendo aren't just going to hand the information over to you!) and the exact behavior of such systems had to be meticulously reverse engineered.

and can mimic a motorola 68k plus the zilog co-processor what must take so long?

Well, emulating CPUs, especially dual-processor systems, is not easy. Emulating the video processors is probably even more challenging, especially with older systems which often had to be cycle-exact to the CPU to work properly. This is also typically where the most undocumented/grey-area happens. Also the code must be efficient and fast to emulate at 60fps or anything near it. It's hard. Can you even program in 68000?

i believe one can make a genesis emulator in like 3 months max if they work every day at it.

Possibly if you are only targeting compatibility with a few games, and can use existing m68k+Z80 emulator code (and have experience using it), it may be.