The most distinctive of the MSX micros to arrive in the UK was launched last week by Yamaha. The CX5 combines the standard micro with an FM sound synthesiser, so that the array of ports at the back of the machine includes in and out sockets for Midi (Musical Instrument Digital Interface) devices. With a small keyboad, the CX5 costs £534; the larger keyboad lifts it to £614. A 8K RAM expansion costs £65, and various items of ROM software for musicians cost £36 each.