attract_loop.txt

Attract Loops
=============
Most arcade games have an attract sequence of some sort. USER_REQUEST Command 2
is used to tell the game to run the demo (or possibly even play the game, but
that's beyond the scope of this document).

Common attract loops typically include the following:
* Content Warning screen (if set to US mode or with a game soft dip [Euro])
* Introduction sequence
* Title screen
* Gameplay demonstration
* High Score screen
Not every Neo-Geo game released includes all of the above, but they're typically
found within the 150-odd MVS game library. Content Warning screens were only
added to games around the mid-1990s (starting with Real Bout Fatal Fury?).

In order to have a "good" attract loop setup, you should have the following:
* A variable to note if you're in attract/demo mode or not
* A variable for the current position in the attract/demo sequence
* At least one timer, for timing the attract sequence (can be reused)
* Other timers, for events in the attract sequence

Multiple Intros
---------------
Garou: Mark of the Wolves does this, and in theory, it's pretty simple.
* MVS: read and update a value in the MVS Backup RAM.
* Home consoles: One of two options.
 1) seed the initial value with a random number, then update that.
 2) Don't care and just start with the first one on every boot.