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 but may be a comma "" in other countries (mainly in Europe). For representing a nonnegative number, a decimal consists of It is generally assumed that, if , the first digit is not zero, but, in some circumstances, it may be useful to have one or more 0's on the left. This does not change the value represented by the decimal. For example, . Similarly, if , it may be removed, and conversely, trailing zeros may be added without changing the represented number. For example, and . sometimes, the unnecessary zeros are used for indicating the accuracy of a measurement.