GEMS

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GEMS Graphical User Interface.png

GEMS
System(s): Mega Drive, Sega 32X
Developer:

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GEMS (Genesis Editor for Music and Sound effects) is a Sega Mega Drive sound driver developed by Recreational Brainware. Commissioned by Sega of America to assist Western developers struggling with the unfamiliar sound hardware, it went on to see use in nearly 200 released games.

Development

History

Early Sega Genesis hardware documentation was limited in all areas, but especially in audio capabilities. Unlike Japanese composers, who were more familiar with writing sound drivers and working with FM synthesis, their Western counterparts struggled to produce quality sounds. Seeking to address this, Sega of America reached out to developer Recreational Brainware to produce a solution.

The team consisted of Jonathan Miller creating drivers and firmware, Burt Sloane programming, and Chris Grigg and Mark Miller providing the software’s overall design. The result was GEMS, a 16-bit sound driver with a focus on MIDI interactivity. Sega of America was very pleased with GEMS and went on to distribute it to their various developers and publishers. Western composers and musicians now had a more familiar and reliable method for translating their instruments to the Sega Genesis hardware.

While GEMS is a very capable driver in the proper hands, it has also grown to absorb much of the ire modern fans have for the “twangy” sounds of certain Western-produced Sega Mega Drive games. As the driver was both widely distributed to developers of all quality, and largely used by developers unfamiliar with the hardware, much of the system’s shovelware library share a distinct (and poorly received) sound.

Usage

The software integrates a programming language that can be built into the composition file and is context-sensitive to gameplay events within the game itself. This is acomplished by setting aside shared memory space that will allow the sound driver to comunicate with the game and vice-versa. Using this technique, the music can change to reflect conditions within the game. For instance, it can be used to track the number of enemies onscreen and change pitch or tempo when a certain threshold is reached or it can be timed to play when certain effects, such as flashes of light, are used.

GEMS Graphical User Interface (alt).png

While in games using other drivers, such Alien Soldier, Dick Tracy or Shinobi III basic behaviour such as playback speed is controlled by a single variable (which can be easly manipulated by an action replay or hex editor), GEMS has to change the data of the whole music track stored on the ROM for the same effect. This can be easily noticed by comparing data in partially PAL optimized games, such as Cool Spot.

Games that use GEMS

Mega Drive

32X

Development kit

On September 24, 2007, drx released the official GEMS development kit.

Download.svg Download GEMS Development Kit
File: GEMS.zip (324 kB) (info)

References