Weighing scale
The balance (also balance scale, beam balance and laboratory balance) was the first mass measuring instrument invented. In its traditional form, it consists of a pivoted horizontal lever with arms of equal lengththe beamand a weighing pan suspended from each arm (hence the plural name ""scales" for a weighing instrument). The unknown mass is placed in one pan and standard masses are added to the other pan until the beam is as close to equilibrium as possible. In precision balances, a more accurate determination of the mass is given by the position of a sliding mass moved along a graduated scale. Technically, a balance compares weight rather than mass, but, in a given gravitational field (such as Earth's gravity), the weight of an object is proportional to its mass, so the standard masses used with balances are usually labeled in units of mass (e.g. g or kg).
Electronic musical instrument
The first digital synthesizers were academic experiments in sound synthesis using digital computers. FM synthesis was developed for this purpose; as a way of generating complex sounds digitally with the smallest number of computational operations per sound sample. In 1983 Yamaha introduced the first stand-alone digital synthesizer, the DX-7. It used frequency modulation synthesis (FM synthesis), first developed by John Chowning at Stanford University during the late sixties. Chowning exclusively licensed his FM synthesis patent to Yamaha in 1975. Yamaha subsequently released their first FM synthesizers, the GS-1 and GS-2, which were costly and heavy. There followed a pair of smaller, preset versions, the CE20 and CE25 Combo Ensembles, targeted primarily at the home organ market and featuring four-octave keyboards. Yamaha's third generation of digital synthesizers was a commercial success; it consisted of the DX7 and DX9 (1983). Both models were compact, reasonably priced, and dependent on custom digital integrated circuits to produce FM tonalities. The DX7 was the first mass market all-digital synthesizer. It became indispensable to many music artists of the 1980s, and demand soon exceeded supply. The DX7 sold over 200,000 units within three years.