The Addiator Hexadat is an adding-subtracting mechanical calculator working to base 16 (hexadecimal). In the hexadecimal system there are 16 symbols or possible digit values from 0 to 9, followed by six alphabetic characters - A, B, C, D, E and F. These characters are used to represent decimal values from 10 to 15 in single bits. In computing systems, the binary string equivalents of large decimal numbers can become quite long. When 16- or 32-bit numbers are involved, it becomes difficult to read and write them without making mistakes. These problems can be overcome by arranging the binary numbers into groups of four bits, i.e., by using the hexadecimal numbering system. Computers such as the IBM 360, Siemens Serie 4004, Univac 9000, Telefunken TR 4, 10, 440, NCR-Centrury, or the Bull Gamma 140 all used the hexadecimal system, and this calculator allowed their operators and programmers to calculate hexadecimal numbers with ease.

In case with stylus, instruction sheet and decimal-hex conversion sheet.

Manufacturer: Addiator
Date: Unknown

This exhibit has a reference ID of CH34358. Please quote this reference ID in any communication with the Centre for Computing History.

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