TOPS-20 Commands Reference Manual

Appendix A Functional grouping of TOPS-20 commands

This appendix lists and briefly explains all non-privileged commands in the TOPS-20 command language, grouping them in categories of similar use.

A.1 System access commands

These commands allow you to gain and relinquish access to the system, to activate and deactivate any special capabilities you have been given, and to disengage and engage jobs to your terminal.

ATTACH Engages a designated job to your terminal.
DETACH Disengages your current job from your terminal.
DISABLE Deactivates any special capabilities you have been granted.
ENABLE Activates any special capabilities you have been granted.
LOGIN Gains access to the TOPS-20 system.
LOGOUT Relinquishes access to the TOPS-20 system.
UNATTACH Disengages another job from its terminal.

A.2 File system commands

The file system commands allow you to create, examine, change, and delete files.

ACCESS Obtains ownership rights to the specified directory, as well as the group rights of the directory's owner.
APPEND Adds contents of one or more files to another file.
ARCHIVE Makes a permanent off-line copy of files.
BUILD Creates, modifies, or deletes a subdirectory.
CLOSE Closes files left open by a program, and releases unopened JFNs.
CONNECT Connects you to the specified directory.
COPY Duplicates files.
CREATE Invokes your defined editor to create a file.
DEFINE Associates a logical name with one or more filespecs.
DELETE Marks files for eventual erasure (disk files only), or erases the files (all other devices).
DIRECTORY Gives information about the files in a directory.
DISCARD Gives up the tape copy of specified on-line files.
EDIT Invokes your defined editor to modify a file.
END-ACCESS Relinquishes ownership rights to the specified directory.
EXPUNGE Permanently erases any deleted files.
FDIRECTORY Lists all the information about files.
PERUSE Edits files in read-only mode.
RENAME Changes one or more parts of an existing file specification.
RETRIEVE Restores off-line files to disk.
TDIRECTORY Lists the names and write dates of files in the order of the date and time they were last changed.
TYPE Prints files on your terminal.
UNDELETE Restores files marked for erasure.
VDIRECTORY Lists the names of files, as well as their protection, size, and the date and time they were last changed.

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 backward.
DEASSIGN Releases a previously assigned device.
DISMOUNT Gives up access to the specified structure or tape set.
EOF Writes an end-of-file mark on a magnetic tape.
MOUNT Requests use of the specified structure or tape set.
REWIND Moves a magnetic tape backward to its load point.
SKIP Moves a magnetic tape forward.
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 run and debug your own programs.

COMPILE Translates a source program using the appropriate compiler.
CONTINUE Resumes execution of a program (e.g., one interrupted by a CTRL/C).
CREF Runs the CREF program, which produces a cross-reference listing and automatically sends it to the line printer.
CSAVE Saves in a compressed executable format the program currently in memory. (Usually SAVE is better for most purposes.)
DDT Merges the loaded debugging program (or if none, DDT) with the current program and then starts the debugging program.
DEBUG Compiles a source program, loads it with a compatible debugging program, and starts the debugging program.
DEPOSIT Sets the contents of the specified memory location.
ERUN Runs a system program in an ephemeral fork.
EXAMINE Checks the contents of the specified memory location.
EXECUTE Compiles, loads, and begins execution of a program.
FORK Selects the current fork to which TOPS-20 commands apply.
FREEZE Stops a running fork.
GET Places an executable program in memory.
KEEP Protects a fork from being cleared from memory.
LOAD Compiles a program and loads it into memory.
MERGE Places an executable program in memory and merges it with the current contents of memory.
POP Finishes a level of TOPS-20 and returns control to the previous level of TOPS-20.
PUSH Starts a new level of TOPS-20.
R Runs a system program.
REENTER Starts the program currently in memory at the alternate entry point specified in the program's entry vector.
RESET Clears memory for the specified fork of your job and its inferiors.
RUN Places an executable program in memory and starts it.
SAVE Copies the contents of memory into a file in executable format.
START Begins execution of the program in memory.
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 Gives an explanatory message about specific system programs.
INFORMATION Provides information about your job and its use of available computing resources, and about the system.
SYSTAT Gives a summary of information about current jobs on the system.
TRANSLATE Tells you what project-programmer number is associated with a directory name, and vice versa.

A.6 Terminal commands

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

ADVISE Sends whatever you type on your terminal as input to a job engaged to another terminal.
BLANK Clears your display screen and moves the cursor to line 1.
BREAK Clears communication links.
RECEIVE Allows your terminal to receive communication links, advice, or system messages from other users.
REFUSE Denies links, advice, or system messages to your terminal.
REMARK Notifies the system that your terminal is not sending commands but only comments.
SET Establishes certain job-wide characteristics for your terminal session.
SET HOST Connects the terminal to another system.
SEND Sends messages to terminals.
TAKE Executes commands contained in the specified file.
TALK Links two terminals so that each user can observe what the other user is doing, without affecting his job.
TERMINAL Informs the system of your terminal type, and lets you determine the setting of its variable parameters.

A.7 Output commands

These commands allow you to request output listings of files on the plotter, line printer, card punch, or paper tape punch, and to examine, modify, or withdraw these requests.

CANCEL Withdraws requests from an output queue (waiting list).
INFORMATION OUTPUT-REQUESTS Lists entries in the output queues.
MODIFY Changes entries in an output queue.
PLOT Places requests in a plotter output queue.
PRINT Places requests in a line printer output queue.
PUNCH Places requests in a card punch or paper tape punch output queue.

A.8 Batch commands

The TOPS-20 system also has a batch system to which you can submit jobs for execution.

CANCEL BATCH Withdraws entries from the batch input queue (waiting list).
INFORMATION BATCH-REQUESTS Lists entries in the batch input queue.
MODIFY BATCH Changes entries in the batch input queue.
SUBMIT Places a batch control file in the batch input queue.