Sierra General MIDI Driver w/ SFX support
Summary

This driver provides General MIDI and digital sound effects on earlier SCI1-based Sierra games where the MIDI and SFX code are in the same driver.

Updated Feb 28, 2012: Added genmidi.zip to obtain the 4.PAT patch file (I thought this came with the game when I first wrote this), added info on Hoyle 3 and Dr Brain, and updated the links section with the new locations of various sites.

Overview

Most (if not all) of Sierra's SCI1 games have MIDI music and digital sound effects. Depending on the version of the interpreter, this can be supported in several ways. In later SCI1 interpreters (such as Space Quest 5, Police Quest 1, and Conquests of the Longbow) Sierra used separate drivers for music and sound effects. However in earlier interpreters (such as Space Quest 1 and Leisure Suit Larry 5) the logic to handle both music and sound effects were in the same driver.

To receive the best-quality MIDI music, a General MIDI (GM) compatible wavetable synthesizer is recommended over a FM synth. Wavetable synths of the day were the Roland MT-32 (though it was not GM compatible) and the Sound Blaster AWE32 while popular FM synths were the Adlib and Sound Blaster 16. Furthermore, the Sound Blaster series were popularized by thier ability to playback digitized sound effects. Today, all sound cards can playback recorded sounds and nearly all are GM compatible. But back in the day, the only way to do both was to buy an AWE32 (which wasn't available until the mid-90's) or connect an MT-32 to an SB card. Furthermore, the game had to have the correct drivers to support these options.

In those earlier SCI1 games, if you want to hear the digitized sound effects, you have two options:

    Use the SNDBLAST.DRV driver (for SB cards) which uses the FM synth for MIDI music.
    Use the MTBLAST.DRV driver (for an MT-32 connected to an SB) which expects to talk to a real MT-32. MT-32 used a different instrument mapping than GM, so if you select this option on a GM-compatible card then the instruments will sound all wrong.

Unfortunately, there was no way to have GM-compatible MIDI music and digital sound effects. This driver, GMBLAST.DRV, corrects this problem.
Affected Games

The following games have been tested to work with this driver:

    Space Quest 1 (SCI version)
    Leisure Suit Larry 1 (SCI version)
    Leisure Suit Larry 5
    Hoyle's Official Book of Games Vol 3

The following games would also work if there were an appropriate instrument patch. Unfortunately, their use is not recommended at this time as the instruments will not sound correct.

    Police Quest 3
    The Castle of Dr Brain 