Search results
Results from the WOW.Com Content Network
The ten-key notation input method first became popular with accountants' paper tape adding machines. It generally makes the assumption that entered numbers are being summed, although other operations are supported. Each number entered is followed by its sign (+/−), and a running total is kept.
To add, for example, the amounts of 30.72 and 4.49 (which, in adding machine terms, on a decimal adding machine is 3,072 plus 449 "decimal units"), the following process took place: Press the 3 key in the column fourth from the right (multiples of one thousand), the 7 key in the column second from right (multiples of ten) and the 2 key in the ...
Comptometer from the 1920s, with nines' complements marked on each key. The method of complements was used in many mechanical calculators as an alternative to running the gears backwards. For example: Pascal's calculator had two sets of result digits, a black set displaying the normal result and a red set displaying the nines' complement of ...
These can be used for special functions. For example, in the UK, users can order a 7:30 am alarm call from a BT telephone exchange by dialing: 55 0730#. [8] In the Americas and a number of other countries, most dials and, later, keypads also bear letters according to the following system: A standard telephone keypad
The name used to denote the dimensions, power supply type, location of mounting holes, number of ports on the back panel, etc. control store The memory that stores the microcode of a CPU. Conventional Peripheral Component Interconnect (Conventional PCI) Also simply PCI. A computer bus for attaching hardware devices in a computer. core
The machine could add and subtract six-digit numbers, and indicated an overflow of this capacity by ringing a bell. The adding machine in the base was primarily provided to assist in the difficult task of adding or multiplying two multi-digit numbers. To this end an ingenious arrangement of rotatable Napier's bones were mounted on it.
Luigi Torchi invented the first direct multiplication machine in 1834: this was also the second key-driven machine in the world, following that of James White (1822). [15] It was not until the 19th century and the Industrial Revolution that real developments began to occur. Although machines capable of performing all four arithmetic functions ...
The most common examples are adding machines and mechanical counters, which use the turning of gears to increment output displays. More complex examples could carry out multiplication and division—Friden used a moving head which paused at each column—and even differential analysis.