Bar (unit) mb (rather than the proper mbar) to denote the millibar. Between 1793 and 1795, the word bar was used for a unit of weight in an early version of the metric system. Atmospheric air pressure is often given in millibars, where standard atmospheric pressure at sea level is defined as 1013.25 mbar, 101.325 kPa, 1.01325 bar, which is about . Despite the millibar not being an SI unit, meteorologists and weather reporters worldwide have long measured air pressure in millibars as the values are convenient. After the advent of SI units, some meteorologists began using hectopascals (symbol hPa) which are
BBC Micro expansion unit MHz. It runs the non-graphical Panos operating system. Various programming languages are available including C, FORTRAN, Lisp, and Pascal, in addition to a version of BBC BASIC. The processor comes with 1 MB of RAM as standard. The processor is also inside the "Acorn Cambridge Workstation" this time using 10 MHz parts and 4 MB of RAM, sold as part of the Acorn Business Computer line. The Universal Second Processor Unit was an adapter for BBC Master internal co-processor boards, to allow them to be used as external co-processors. It comprised a power supply, interface logic and a connector that