MOD Format Overview

Let's take a closer look at what the MOD format is capable of.

Basically, the MOD format contains 3 things: an order list, patterns, and samples. There's also a couple other things such as the signature and title.

The order list is just a sequence of pattern indexes to play.

The samples contain a small header and raw 8-bit signed PCM sample data. The header contains things like the volume, looping points, and tuning.

The patterns can be thought of as sheet music. They contain a sequence of notes and sample numbers to control the music. Each entry in the pattern also contains a special column that can produce a certain effect on the note being/about to be played.

So, to play a MOD, you basically just read through the entries in the order list and run through each pattern that is listed. The patterns are made up of 64 rows and X columns, where X is the number of channels that the module contains.

We'll go more in-depth into the format once we have a working audio mixer.