TOPS-20 User's Guide

Appendix A TOPS-20 Commands

This appendix contains a brief explanation of the commands in the TOPS-20 Command Language. The commands are grouped in categories of similar use. Although some of these commands are not described in this manual, the purpose of this list is to make you aware of the full extent and capability of the TOPS-20 Command Language. For a complete description of all TOPS-20 commands, refer to the TOPS-20 Commands Reference Manual.

  1. System access commands
  2. File system commands
  3. Device handling commands
  4. Program control commands
  5. Information commands
  6. Terminal commands
  7. Batch command


A.1 System access commands

These commands allow you to gain and relinquish access to the system, to change jobs, and to release and connect terminals to your job.

        ATTACH           Connects your terminal to a designated job.

        DETACH           Disconnects your terminal from the  current  job
                         without affecting the job.

        DISABLE          Returns a privileged user to normal status.

        ENABLE           Permits privileged users to  access  and  change
                         confidential system information.

        LOGIN            Gains access to the TOPS-20 system.

        LOGOUT           Relinquishes access to the TOPS-20 system.

        UNATTACH         Disconnects a terminal from a job; it  does  not
                         have to be the terminal you are using.


A.2 File system commands

The file system commands allow you to create and delete files, to specify where they are to be stored, to copy them, and to output them on any device.

        ACCESS           Grants ownership and group rights to a specified

        APPEND           Adds information from one or more  source  files
                         to a new or existing disk file.

        ARCHIVE          Marks a file for long-term off-line storage.

        BUILD            Allows  you  to  create,  change,   and   delete

        CANCEL           Removes files from any of several system queues.

        CLOSE            Closes a file or files left open by a program.

        CONNECT          Removes you  from  your  current  directory  and
                         connects you to a specified directory.

        COPY             Duplicates a file in a destination file.

        CREATE           Invokes your defined editor to create a file.

        DELETE           Marks  the  specified   file(s)   for   eventual
                         deletion (disk files only).

        DEFINE           Associates a logical name with one or more file,
                         directory, or structure names.

        DIRECTORY        Lists  the  names  of  files  residing  in   the
                         specified  directory and information relating to
                         those files.

        DISMOUNT         Notifies the system that the given structure  or
                         magnetic tape is no longer needed.

        EDIT             Invokes your defined editor to modify a file.

        EXPUNGE          Permanently removes any deleted files  from  the

        END-ACCESS       Relinquishes ownership and  group  rights  to  a
                         specified directory.

        FDIRECTORY       Lists all the information about a file or files.

        MODIFY           Changes and/or adds  switches  to  a  previously
                         issued PRINT or SUBMIT command.

        MOUNT            Requests that a structure or a magnetic tape  be
                         made available to the user.

        PERUSE           Invokes your defined editor to read an  existing
                         file in read-only mode.

        PRINT            Enters one or more files  in  the  line  printer

        RENAME           Changes one or more descriptors of  an  existing
                         file specification.

        RETRIEVE         Requests restoration of a file stored off-line.

        TDIRECTORY       Lists the names of all files in the order of the
                         date and time they were last written.

        TYPE             Types one or more files on your terminal.

        UNDELETE         Restores one  or  more  disk  files  marked  for

        VDIRECTORY       Lists the names of all files, as well  as  their
                         protection,  size,  and  date and time they were
                         last written.


A.3 Device handling commands

These commands allow you to reserve a device prior to using it, to manipulate the device, and to release it once it is no longer needed.

        ASSIGN           Reserves a device for use by your job.

        BACKSPACE        Moves a magnetic tape drive back any  number  of
                         records or files.

        DEASSIGN         Releases a previously assigned device.

        EOF              Writes an end-of-file mark on a magnetic tape.

        REWIND           Positions a magnetic tape backward to  its  load

        SKIP             Advances a magnetic tape one or more records  or

        UNLOAD           Rewinds a magnetic tape until the tape is  wound
                         completely on the source reel.


A.4 Program control commands

The following commands help you create, run, edit, and debug your own programs.

        COMPILE          Translates a source module using the appropriate

        CONTINUE         Resumes execution of a program interrupted by  a
                         CTRL/C or the FREEZE command.

        CREF             Runs  the  CREF   program   which   produces   a
                         cross-reference  listing and automatically sends
                         it to the line printer.

        CSAVE            Saves the program currently in memory so that it
                         may  be  used  by  giving  a  RUN  command.  The
                         program is saved in a compressed format.

        DDT              Merges the  debugging  program,  DDT,  with  the
                         current program and then starts DDT.

        DEBUG            Takes a source program, compiles  it,  loads  it
                         with  the  appropriate  debugger  and starts the

        DEPOSIT          Places a value in an address in memory.

        ERUN             Runs  an  executable  program  in  an  ephemeral
                         (transitory) fork.
        EXAMINE          Allows you to examine an address in memory.

        EXECUTE          Translates, loads, and  begins  execution  of  a

        FREEZE           Stops a running program.

        FORK             Selects  the  fork  to  which  TOPS-20  commands

        GET              Loads an executable program from  the  specified
                         file into memory, but does not start it.

        KEEP             Protects a fork from being cleared from memory.

        LOAD             Translates a program (if necessary) and loads it
                         into memory.

        MERGE            Merges an executable program  with  the  current
                         contents of memory.

        POP              Stops the current active  copy  of  the  TOPS-20
                         command   level   and  returns  control  to  the
                         previous command level.

        PUSH             Preserves the contents of memory at the  current
                         command  level and creates a new TOPS-20 command

        R                Runs a system program.

        REENTER          Starts the program currently  in  memory  at  an
                         alternate entry point specified by the program.

        RESET            Clears the current job.

        RUN              Loads an executable  program  from  a  file  and
                         starts  it  at  the  location  specified  in the

        SAVE             Copies the contents of memory  into  a  file  in
                         executable   format.    If   memory  contains  a
                         program, you may  now  execute  the  program  by
                         giving the RUN command.

        SET              Sets  various  parameters  for   your   job,   a
                         directory, a file, or a device.

        START            Begins execution of a program previously  loaded
                         into memory.

        TRANSLATE        Translates  a  project-programmer  number  to  a
                         directory   name   or  a  directory  name  to  a
                         project-programmer number.

        UNKEEP           Cancels the kept status of a fork.


A.5 Information commands

These commands return information about TOPS-20 commands, your job, and the system as a whole.

        DAYTIME          Prints the current date and time of day.

        HELP             Prints information about system features.

        INFORMATION      Provides  information  about  your  job,  files,
                         memory,  errors,  system status, queue requests,
                         and other parameters.

        SYSTAT           Outputs a summary of system users and  available
                         computing resources.


A.6 Terminal commands

The terminal commands allow you to clear your video terminal screen, to declare the characteristics of your terminal, and to control linking to another user's terminal.

        ADVISE           Sends whatever you  type  on  your  terminal  as
                         input to a job connected to another terminal.

        BLANK            Clears the video terminal screen and  moves  the
                         cursor to the first line.

        BREAK            Clears a  terminal  links  made  with  the  TALK

        RECEIVE          Allows your terminal to receive links and advice
                         from other users.

        REFUSE           Denies links and advice to your terminal.

        REMARK           Allows you to type many lines of text when using
                         the TALK command.

        SEND             Sends a message to another user's terminal.

        SET              Establishes certain job-wide characteristics for
                         the terminal.

        SET HOST         Connects the terminal to another system.

        TAKE             Accepts TOPS-20 commands from a file, just as if
                         you had typed them on your terminal.

        TALK             Links  two  terminals  so  that  each  user  can
                         observe  what  the other user is doing, yet does
                         not affect either user's job.

        TERMINAL         Declares the type of terminal you have, and lets
                         you    inform    TOPS-20    of    any    special
                         characteristics of the terminal.


A.7 Batch command

The TOPS-20 operating system also has a Batch System to which you may submit jobs for later execution.

        SUBMIT           Enters a file  into  the  Batch  waiting  queue.
                         When   it  is  your  job's  turn,  the  commands
                         contained in the file are executed.