(1) (DIR) (
Digital
Instrumentation
Recorder) An earlier 19mm, helical-scan magnetic tape technology from Sony, earmarked end of life in 2004. Based on the D1 format, DIR was fast enough for sonar, radar and other high-speed data archiving. Cassettes came in 8.7GB, 43GB and 96GB capacities. Once a standard in the U.S. government, DIR was gradually replaced by LTO and SAIT technologies. See
DTF,
LTO,
AIT and
magnetic tape.
DIR Cassettes Were Huge
Next to the 4mm DAT cassette, the 96GB DIR cassette was enormous.
(2) (
DIRectory) A DOS/Windows internal command that lists the file names on disk. Originating with the CP/M operating system, Dir is widely used by Windows programmers and power users. Following are various examples:
dir names, date and size
dir /w no date and size
dir /p pause each screenful
dir /ad only folders
dir *. only folders plus files
without extensions
dir *.jpg all files
dir *.mp3 of a
dir *.doc certain
dir *.exe type
DIFFERENT SEQUENCES
dir /o folders, then files
dir /oe by extension a to z
dir /o-e by extension z to a
dir /os small to large
dir /o-s large to small
dir /od earliest to latest
dir /o-d latest to earliest
BY ATTRIBUTE
dir /ar read only files
dir /ah hidden files
dir /aa files to be archived
dir /as system files
FIND DUPLICATE FILES
The following example finds all files named X.BAT anywhere in the C: drive, because the command is initiated at the root of the drive (C:\>):
C:\>dir x.bat /s