Digital Equipment DEC 3000 Series Service Information page 410

Fiber Distributed Data Interface (FDDI)
An ANSI-standard high-speed network technology that uses fiber
optics as the transmission medium. FDDI employs a ring topology
and operates up to 100 km in total network length. It uses 1300
nm wavelengths, which optimize fiber bandwidth.
field replaceable unit (FRU)
Any system component that can be replaced by your Digital
service representative.
file
A collection of related information treated by the system as a
unit.
firmware
Software code that is stored in a fixed way (wired in), usually in
read-only memory. The firmware executes when the system is
turned on, during operating system boot and restarts, and as a
result of operator intervention or a fatal system error.
FIS
See Factory Installed Software.
fixed disk
A disk that resides permanently inside a disk drive. Compare
with diskette.
fixed disk drive
The disk drive that holds and reads from or writes to a fixed disk.
floating point
A number that may be positive or negative but that has a whole
(integer) portion and a fractional (decimal) portion; an arithmetic
operation in which the decimal point is not fixed, but placed
automatically in a correct position in a computer word.
frame buffer
An area of memory that contains a pixel-level description of a
displayed image. The frame buffer is also used to refresh the
raster display.
FRU
See Field Replaceable Unit.
gigabyte (GB)
The measure used to refer to memory or secondary storage
capacity, equal to 1,024 megabytes or 1,073,741,824 bytes.
Glossary–10