A quartz clock is a clock that uses an electronic oscillator that is regulated by a quartz crystal to keep time. This crystal oscillator creates a signal with very precise frequency, so that quartz clocks are at least an order of magnitude more accurate than mechanical clocks. Generally, some form of digital logic counts the cycles of this signal and provides a numeric time display, usually in units of hours, minutes, and seconds. The first quartz clock was built in 1927 by Warren Marrison and J.W. Horton at Bell Telephone Laboratories. Since the 1980s when the advent of solid state digital electronics allowed them to be made compact and inexpensive, quartz timekeepers have become the world's most widely-used timekeeping technology, used in most clocks and watches, as well as computers and other appliances that keep time.