A.R. Rahman mentions about his discovery with his first MIDI computer Yamaha CX5M in 3:05 section of this video . This is the first MIDI based keyboard used by A.R. Rahman. It came in 1984. His friend gifted him in the same year. After experimenting with synthesizers and working as a Keyboard player for music directors for many years, he discovered Yamaha CX5M MIDI computer. He experiments many sounds with this MIDI computer.more
It is a MSX music computer by Yamaha which was designed to be the platform to control and edit all your music gear. The version depicted is a CX5M-II which had more ram and extra built in software. Both CX% computer flavours had built-in 4-op FM like the FB-01 and DX-11. The cartridges available varied from learning chords, designing artwork to editing your DX or RX machine sounds.