 Yamaha has made several models with such features, with their DX synthesizer in the 1980s, such as the DX1, DX5 and DX7 and their PSR keyboard lineup in the mid-1990s, namely the "PSR-320, PSR-420, PSR-520, PSR-620, PSR-330, PSR-530" and the "PSR-6000".These keyboards use specialized cards known as "Music Cartridges", a ROM cartridge simply containing MIDI data to be played on the keyboard as MIDI sequence or song data.This technology, however, quickly become obsolete and extremely rare after the advent of floppy disk drive in later models.