The Yamaha OPL series of sound chips (FM Operator tyPe-L) utilized FM synthesis and were used in a variety of home computers and other devices. '[#[YM3526 OPL] The first OPL chip had 9 channels of two operator FM synthesis using a sine wave. It saw limited use in home computer expansions and a few arcade games. '[#[YM3812 OPL2] The OPL2 saw a very wide distribution on the Adlib and Sound Blaster PC soundcards of the mid 1980s through early 90s. It had 9 channels of two operator FM synthesis like the first OPL, but included 3 additional waveforms (all variations on the sine wave). For PCs, the Sound Blaster cards were generally preferred to the Adlib cards because SB had digital audio support while the Adlibs did not. Later SB cards would use the improved OPL3. '[#[YMF262 OPL3] Popularly used on later SB cards, the OPL3 had several improvements over the OPL2. These improvements include: 18 channels of two operator FM synthesis, 8 waveforms (including square and logarithmic saw), stereo support, and the ability to combine channels to create 4 operator FM synthesis. '[#[YMF278 OPL4] Not as widely distributed as the OPL2 or OPL3, the OPL4 had all the capabilities of the OPL3 and sample based synthesis abilities. '[#[Links] '[l[http://www.shipbrook.com/jeff/sb.html[OPL programing infos] '[l[http://adlib.wave460.net/trackers.html[Huge list of OPL trackers]
