Refers to a type of floating-point number that has more precision (that is, more digits to the right of the decimal point) than a single-precision number. The term double precision is something of a misnomer because the precision is not really double. The word double derives from the fact that a double-precision number uses twice as many bits as a regular floating-point number. For example, if a single-precision number requires 32 bits, its double-precision counterpart will be 64 bits long.
The extra bits increase not only the precision but also the range of magnitudes that can be represented. The exact amount by which the precision and range of magnitudes are increased depends on what format the program is using to represent floating-point values. Most computers use a standard format known as the IEEE floating-point format.
- double-sided disk
A floppy disk with both sides prepared for recording data. You can store twice as much data on a double-sided disk, but you need to use a double-sided disk drive. All modern disks and disk drives are double-sided.
Not working. A computer system is said to be down when it is not available to users. This can occur because it is broken (that is, it has crashed), or because it has been made temporarily unavailable to users so that routine servicing can be performed.
In digital television, downconversion is the process where a high-definition signal is converted to a standard-definition picture to be displayed on a television with a lower resolution. Downconversion reduces image detail but the picture will still look quite sharp. Contrast with upconversion.
- down converter
In satellite communications, down converter is a device for fixed satellite service (FSS) television receivers to convert 4-GHz signals to the 70-MHz frequency range.
In satellite communications, downlink is the establishment of a communications link from an orbiting satellite down to one or more ground stations on Earth. Contrast with uplink.