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.
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.
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 directory. 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 subdirectories. 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 disk. 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 queue. 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 deletion. VDIRECTORY Lists the names of all files, as well as their protection, size, and date and time they were last written.
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 point. SKIP Advances a magnetic tape one or more records or files. UNLOAD Rewinds a magnetic tape until the tape is wound completely on the source reel.
The following commands help you create, run, edit, and debug your own programs.
COMPILE Translates a source module using the appropriate compiler. 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 debugger. 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 program. FREEZE Stops a running program. FORK Selects the fork to which TOPS-20 commands apply. 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 level. 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 program. 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.
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.
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 command. 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.
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.