Editing OS/8 (section)

==The Concise Command Language==
Early versions of OS/8 have a very rudimentary [[command-line interpreter]] with very few basic [[command (computing)|commands]]: {{mono|GET}}, {{mono|SAVE}}, {{mono|RUN}}, {{mono|ASSIGN}}, {{mono|DEASSIGN}}, and {{mono|[[Octal Debugging Technique|ODT]]}}. With version 3 they add a more sophisticated overlay called ''CCL'' (''[[Concise Command Language]]'') that implements many more commands. OS/8's CCL is directly patterned after the CCL found on Digital's [[PDP-10]] systems running [[TOPS-10]]. In fact, much of the OS/8 software system is deliberately designed to mimic, as closely as possible, the TOPS-10 operating environment. (The CCL command language is used on [[PDP-11]] computers running [[RT-11]], [[RSX-11]], and [[RSTS/E]], providing a similar user operating environment across all three architectures: PDP-8s, PDP-10s, and PDP-11s.)

The basic OS and CCL implements many rather sophisticated commands, many of which still do not exist in modern command languages, not even in [[MS-DOS]], [[Microsoft Windows|Windows]], or [[Unix-like]] operating systems.

For example, the {{mono|COMPILE}} command automatically finds the right compiler for a given source file and starts the compile/assemble/link cycle.

The {{mono|ASSIGN}} and {{mono|DEASSIGN}} commands permit the use of logical device names in a program instead of physical names (as required in MS-DOS). For example, a program can write to device {{mono|FLOP:AAA.TXT}}, and with an initial "{{mono|ASSIGN FLOP: RXA2:}}" then the file is created on physical device RXA2 (the second floppy disk drive). [[VAX]]/[[OpenVMS|VMS]] and the [[Amiga]]'s operating system [[AmigaOS]] (and other OSes built around [[TRIPOS]]) make considerable use of this feature.

The {{mono|SET}} command is capable of setting many system options by patching locations in the system binary code. One of them, a command under OS-78,<ref name="OS78.ref">{{cite web |author=Moore |first=Rick |title=OS-8 Field Service Assistance Brochure |url=https://www.pdp8.net/os/os8/os8_general.shtml}}</ref> is {{mono|SET SYS OS8}}, which re-enables the MONITOR commands that are not part of OS-78.

The {{mono|BUILD}} command can reconfigure the OS on the fly, even adding [[device driver]]s, often without having to reboot the OS.