MultiScrollNES, an example multi-directional scroll engine for the Nintendo Entertainment System (NES). This project is released under the MIT license. References for the various engine routines can be found in the 'documentation' folder.

An example map and CHRRAM editor that uses meta-tiles (2x2 NES PPU tiles) and meta-cells (8x8 meta-tiles) to drastically reduce the storage space required by a given map. Written in C#/XNA. This project is released under the MIT license.

A macro interpretter that allows limited use of comparison operators, bracket scoping, and while loops in 6502 asm files. This project is released under the MIT license. An example of usage follows:

.if a >= #240
{
    ldx delta_hi
    .if x == #$ff
    {
        `add 240
    }
    .else
    {
        `sub 240
    }
}

Assemble using Ophis: http://michaelcmartin.github.io/Ophis/

Runs on iNES Mapper 1 (MMC1). Also includes code which would allow compilation for MMC3 and Action 53 (the latter requires a NES emulator with Mapper 28 support, such as Nintendulator v0.975 Beta). However, these two have not been updated in some time, and would require updating their PRGROM bank references to match the latest changes to the MMC1 PRGROMs.