Decimal computer Decimal computer Decimal computers are computers which can represent numbers and addresses in decimal as well as providing instructions to operate on those numbers and addresses directly in decimal, without conversion to a pure binary representation. Some also had a variable wordlength, which enabled operations on numbers with a large number of digits. Early computers that were exclusively decimal include the ENIAC, IBM NORC, IBM 650, IBM 1620, IBM 7070. In these machines, the basic unit of data was the decimal digit, encoded in one of several schemes, including binary-coded decimal or BCD, bi-quinary, excess-3, and two-out-of-five code. Except for
Decimal computer also included instructions for packed decimal arithmetic as well as binary integer arithmetic, and binary floating point. It used 8-bit characters and introduced EBCDIC encoding, though ASCII was also supported. The Burroughs B2500 introduced in 1966 also used 8-bit EBCDIC or ASCII characters and could pack two decimal digits per byte, but it did not provide binary arithmetic, making it a decimal architecture. Several microprocessor families offer limited decimal support. For example, the 80x86 family of microprocessors provide instructions to convert one-byte BCD numbers (packed and unpacked) to binary format before or after arithmetic operations . These operations were not