First post, by GabrielKnight123
Hi all I have been reading lots to understand the process of how Midi for Dos games work and I would like to get feedback on anything I may have wrong as written below:
System setup would be:
Any ISA sound card that uses FM Synthesis/OPL (2/3/4)/CQM Synthesis
Roland SC55 with cable going from SC55’s input midi port to the joystick port on sound card
A game setup in the install options to use Midi for music and a “sound card type” for effects
SC55’s audio output L/R goes to the sound cards Line In
[GAME]
So the first thing for the Midi music to start is the game sends the Midi file “Standard Midi File (*.SMF)” from the hard drive and through the sound cards joystick/Midi port to the SC55 Midi module
[SC55]
The SC55 gets the SMF file as raw Midi data, I know that a midi file has no “audio/sound” associated with it but it is more like a sheet of music (midi file) with instructions for the musician to play (SC55), the SC55 then uses its built in samples/sound font that the midi file points to and the SC55 uses its internal PCM and cut-down version of the LA synthesis engine to create the musical instrument sounds and then sends it to the audio output for the speakers to play but in my system setup as written above the audio output for the SC55 is sent to the line in of the sound card that then mixes the music and effects to the line out that go to the speakers.
[FM SYNTHESIS]
Early sound cards used FM synthesis, FM synthesis takes tones at varying frequencies and combines them to create an approximation of a particular sound, such as the blare of a trumpet, it is the process of generating sound through modulation of sine waves.
[WAVETABLE SYNTHESIS]
Wavetable synthesizers use actual "digital samples" of real musical instruments, to generate music. These are real, hi-fidelity recordings of the actual instruments. When a MIDI file is played through a high quality "Wavetable" sound card, the sound quality approaches that of an actual CD, but without the storage requirements. Wavetable daughter board cards connect to the Wavetable header on some sound cards.
[OPL 2/3/4]
Is a better version of FM synthesis with a dedicated chip for processing the synthesis made by Yamaha
[CQM]
A clone of the Yamaha OPL chip made outside Yamahas circle
[GENERAL MIDI]
General MIDI is the basis for "Wavetable" synthesis. GM is actually a set of 120 standard sounds, plus drum kit definitions. All "Wavetable" synthesizers and Sound cards use the GM soundset to assure compatibility between the manufacturers.
MIDI allows selection of an instrument's sounds through program change messages, but there is no guarantee that any two instruments have the same sound at a given program location. Program #0 may be a piano on one instrument, or a flute on another. The General MIDI (GM) standard was established in 1991, and provides a standardized sound bank that allows a Standard MIDI File created on one device to sound similar when played back on another. The GM standard eliminates variation in note mapping
[GS, XG, and GM2]
A general opinion quickly formed that the GM's 128-instrument sound set was not large enough. Roland's General Standard, or GS, system included additional sounds, drumkits and effects, provided a "bank select" command that could be used to access them, and used MIDI Non-Registered Parameter Numbers (NRPNs) to access its new features. Yamaha's Extended General MIDI, or XG, followed in 1994. XG similarly offered extra sounds, drumkits and effects, but used standard controllers instead of NRPNs for editing, and increased polyphony to 32 voices. Both standards feature backward compatibility with the GM specification, but are not compatible with each other. Neither standard has been adopted beyond its creator, but both are commonly supported by music software titles.
Member companies of Japan's AMEI developed the General MIDI Level 2 specification in 1999. GM2 maintains backward compatibility with GM, but increases polyphony to 32 voices, standardizes several controller numbers such as for sostenuto and soft pedal (una corda), RPNs and Universal System Exclusive Messages, and incorporates the MIDI Tuning Standard. GM2 is the basis of the instrument selection mechanism in Scalable Polyphony MIDI (SP-MIDI), a MIDI variant for low power devices that allows the device's polyphony to scale according to its processing power.
[SAMPLED BASED]
Well, it's just confusing to call midi/wavetable music "sample-based". Sample-based means that the music file for the game actually comes with all the needed samples (as opposed to using samples from a MIDI device's ROM such as the AWE32). Sample-based music is more or less device-independent. Wavetable/GM is not.
Say, Epic Pinball uses sample-based music, and you don't need AWE32 (or any other GM-compatible device) for that. Any SoundBlaster 16 (or any of its clones) can play that music. Gravis Ultrasound cards produce higher quality music in this game, but it's not using different samples. Also, you can't use soundfonts (i.e. sample sets) to get Epic Pinball to sound differently.
[SOUND FONTS]
Is a file you can use to load into a devices memory that changes the default samples to slightly different quality or sounding instrument samples. Example change the flute to an electric guitar.
The things im not sure about:
[1]
When you have a sound module like the SC55 do all games need the Autoexec.bat setting:
SET MIDI=SYNTH:2 MAP:G MODE:0 to enable the SC55 as the synthesizer to use or does the sound card take care of it when Midi is enabled in game
SYNTH:1 (Internal FM or AWE synth)
SYNTH:2 (External MIDI port / WaveBlaster header)
MAP:G (General MIDI, 1-16)
MAP:E (Extended MIDI, 1-10)
MAP:B (Basic MIDI, 13-16)
MODE:0 - GM (SYNTHGM.SBK)
MODE:1 - GS (SYNTHGS.SBK)
MODE:2 - MT-32 (SYNTHMT.SBK)
[2]
Since its possible to choose internal or external synthesis for a SC55 which is better the SC55 or the sound card, im using the soundcard as a “general” type of FM synthesis/OPL2/3 or CQM I guess this would matter on the soundcard.
[3]
When you install a daughter board card to the wavetable header on a sound card does the sound card stop using FM synthesis and instead use some other sort of synthesis on the daughter board?
[4]
When you plug the audio output from an SC55 to the line in of a sound card does the sound card only process the volume of the line in or is there some synthesis going on?
Midi is still new to me as I havnt really had much use from it but I like it so far and reading wiki pages and posts about all the good old sound card types and tech thats been around just amazes me like when I played my first adventure game I think it was monkey island but with just sound card music and no midi I am setting up a Pc with my first sound module and I hear monkey island is amazing with midi.