Yamaha Corp is planning to bring out two models of an integrated music computer on December 10: the laptop-like machines are powered by 640Kb 80286 processors, and include a keyboard, a liquid crystal display, and a time-code interface unit that can be synchronised with eight MIDI music ports that can simultaneously control as many as 128 instruments or be synchronised with multi-track recordings; the US subsidiary launched the things in September, but disappointed fans by failing to include what is regarded as a pretty special program called Sequence, which programs and arranges compositions for a full orchestra; the C1 has two 3.5 floppies and is $2,700 in Japan, the C1/20 adds a 20Mb hard disk in place of one of the floppies aand is $3,800.