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 floating point different alternative methods. IBM POWER6 and newer POWER processors include DFP in hardware, as does the IBM System z9 (and z10). SilMinds offers SilAx, a configurable vector DFP coprocessor. IEEE 754-2008 defines this in more detail. Fujitsu also has 64-bit Sparc processors with DFP in hardware. Microsoft C#, or .NET, uses System.Decimal. The IEEE 754-2008 standard defines 32-, 64- and 128-bit decimal floating-point representations. Like the binary floating-point formats, the number is divided into a sign, an exponent, and a significand. Unlike binary floating-point, numbers are not necessarily normalized; values with few significant digits have multiple possible representations: 1×10=0.1×10=0.01×10, etc.