TOPS-20 Commands Reference Manual


Places an executable system program in memory and starts it.


@R (PROGRAM) filespec /switch



is the file specification of any executable program.

Default dev:<directory> - SYS:

Default .typ - .EXE

/switch is
/USE-SECTION:n specifies the memory section (from 0 to 37 octal) in which your program is to run. You can use this switch only if your program can be contained in one section.


Need for R Command

Although in most cases you can run system programs by simply typing the program name in place of an EXEC command, the R command is necessary for running a program whose name is the same as an EXEC command or an abbreviation for an EXEC command. For example, if your site has a system program named CONNECT, it must be run with the R command in order to distinguish it from the EXEC's CONNECT command. If you have a system program named GE, it must be run with the R command to distinguish it from the GE abbreviation for the GET command.

Cancels the Ephemeral Attribute

If a system program has been set ephemeral by the system manager or, you have given a SET PROGRAM EPHEMERAL command, you can cancel the ephemeral attribute by running the program with the R command instead of typing the program name as an EXEC command.

For more information on the ephemeral attribute, see the ERUN command.


Defining SYS:

If you redefine logical name SYS: to be different from the system-wide definition, you should include SYS: in the search list if you want to use the R command to run system programs. For further information, see the section entitled, Redefining System Logical Names, in the DEFINE command description.

Effect on Memory

The R command clears any unkept forks, places in memory and starts the specified program.

Related Commands

INFORMATION LOGICAL-NAMES for examining the definition of SYS:
RUN for running executable user programs


  1. Run the FILCOM system program.
  2. Find out what APL programs are available in logical name SYS:. Run one of them.
     Total of 3 files
    @R APL.EXE