In computing, dir (directory) is a command in various computer operating systems used for computer file and directory listing. It is one of the basic commands to help navigate the file system. The command is usually implemented as an internal command in the command-line interpreter (shell). On some systems, a more graphical representation of the directory structure can be displayed using the tree command.
CP/M 3.0 directory listing on a Commodore 128 home computer.
Directory listing on CP/J 2.21 running on an Elwro 804 Junior.
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/85-based microcomputers by Gary Kildall of Digital Research, Inc. CP/M is a disk operating system and its purpose is to organize files on a magnetic storage medium, and to load and run programs stored on a disk. Initially confined to single-tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations and were migrated to 16-bit processors.
CP/M advertisement in the 29 November 1982 issue of InfoWorld magazine
Apple CP/M Card with manual
CP/M Plus (CP/M 3) System Guide
DEC PRO-CP/M-80 floppy-disk distribution for the Z80-A co-processor in a DEC Professional 3xx series