It was not until the advent of MIDI, introduced to the public in 1983, that general-purpose computers really started to play a role as software sequencers. NEC's personal computers, the PC-88 and PC-98, added support for MIDI sequencing with MML programming in 1982. In 1983, Yamaha modules for the MSX featured music production capabilities, real-time FM synthesis with sequencing, MIDI sequencing, and a graphical user interface for the software sequencer. Also in 1983, Roland Corporation's CMU-800 sound module introduced music synthesis and sequencing to the PC, Apple II, and Commodore 64.