[Advent of Code 2023](https://adventofcode.com/2023) on the NES. The whole thing
turned out to be quite tricky on this 8-bit system, with days that required
computing really big numbers. I put up with this for some days, but starting on
the fifth one it was unbearable. Thus, this repo contains only until the fourth
day (included). Each day is written into its own file inside of `src`. In order
to clone it bear in mind that the `vendor` directory has git submodules. Hence:

``` sh
git clone --recurse-submodule https://git.mssola.com/nes/aoc2023.nes
```

Build everything by just calling `make` and you will get a `.nes` file per day
inside of the `out` directory. Before doing that, though, you will need a
compiler for the 6052 platform. A good option is
[cc65](https://github.com/cc65/cc65), which is available on all major platforms.
Otherwise, if you want to use another compiler, you can pass the `CC65` and
`CCOPTS` variables to the Makefile.

After that, it's recommended that you run the ROMs with an emulator with
debugging support or at least some form of memory visualization. This is because
some days have nothing to show for other than updating some values on the NES
memory. A safe bet is to go with either [fceux](https://fceux.com/web/home.html)
or [Mesen](https://github.com/SourMesen/Mesen2/), which provide tools like RAM
watchers or a full debugger. Otherwise, you can run tests with `make test`, but
for now this requires a screen. Thus, we cannot run it on a CI, for now. This is
mainly used so to ensure that changes on shared code don't mess with the end
result from exercises.

Notice also that I will use some terms without actually introducing them. That
is, I expect you to go over the [NES Dev
wiki](https://www.nesdev.org/wiki/Nesdev_Wiki) for glossary or for full
documentation on the stuff being shown here. That is, if you find that on a
bunch of comments I write stuff like "memory mapper", "MMC3 chip", "OAM" or
stuff like that, just go to the [NES Dev
wiki](https://www.nesdev.org/wiki/Nesdev_Wiki) to get a better picture.

## License

Released under the [GPLv3+](http://www.gnu.org/licenses/gpl-3.0.txt), Copyright
(C) 2023-<i>Ω</i> Miquel Sabaté Solà.

The `vendor` directory contains code that might have been written by other
people. Attribution is given on each file.