You already put OS-9 to work with commands such as FORMAT and BACKUP. In these cases the manual told you exactly what to do to accomplish a very specific task. If you want to strike out on your own, you should know some additional background information.


Typing Commands

As explained earlier, some OS-9 files are programs. You tell OS-9 to execute these programs by typing the program (file) name and pressing ENTER . You are then issuing a command to OS-9. That's all a command is, the name of a program for the system to execute. The following are some rules about commands:




A command consists of one word, the command name. A command line consists of one or more command names and their associated parameters and modifiers. Parameters and modifiers are special information you include with a command that provide necessary data for the command to operate, or that affect the command's operation.


- A command line can have a maximum of 198 characters including any combination of upper- or lowercase letters. To execute a command, press ENTER . For example, to clear the screen, type:




Editing Commands
OS-9 is very particular about the commands you type. If you make any mistake, OS-9 either does not understand (and tells you so with an error message) or does the wrong thing.

 If you see that you made a mistake before you press ENTER , you
 0
 have two choices: (1) use E) or CTRL 0 to move the cursor to the
 mistake, and retype that portion of the line, or (2) press CTRL x0
 or sH~ ~ to erase the line you are typing, and start over.
Getting Started With OS-9
Command Parameters

You can follow a command name with one or more parameters that give OS-9 more specific instructions. For example, in the command line:




LIST is the name of the command that displays the contents of a text file. Filel, the specified parameter, is the name of the file that you want displayed.


Note: In a command line, always use spaces to separate parameters from their command, and from each other. Parameters cannot contain spaces. Chapter 6 discusses parameters for each OS-9 command.

Some commands have more than one parameter. For instance, COPY requires two parameters: the name of the file being copied, and the name of the new file you want COPY to create. If you want to copy a file called Startup, and call the copy Newstartup, your command line reads:




                      The name of the copy


You press ENTER to cause the command line to execute. copy Startup new5tartup ENTER


Using Options -

Command lines can also contain another type of parameter, called an option. An option changes the way a command performs. For instance, the command DER, without parameters, shows the name of all files in the current data directory.


5-2
                    Commands and Keys / 5


However, if you add the E option as a parameter to the command, like this:
    d i r e ENTER


the output includes not only the names of the files, but also complete statistics about each file-the date and time created, size, security codes, and so forth. To display complete information about each file in SYS, type:
    d i r s y s e ENTER


Using Commands

As described in Part 1, OS-9 acts in much the same manner as an office manager. It looks after the operation of your computer and equipment. Because OS-9 is only a manager, it expects you to make the necessary decisions.


For example, suppose you have an important file named Hotstuff that you want to copy. Before giving it to your office manager (OS-9), you must make executive decisions, such as:


    · Do you want the copy on disk, paper, or the computer screen?


    · If you want the copy on disk, which disk?


    · If you want the copy on the same disk, what name do you want to give the second copy so OS-9 is not confused?


    · If you want the copy on the computer screen, do you want the display to pause when it fills the screen?


You make the decisions, OS-9 manages the job. For instance, if your decision is to copy Hotstuff from one diskette to to another, you might type the following command line:


    copy /d0/hot5tuff /d1 /hotcopy ENTER


5-3
 Getting Started With OS-9
This is how OS-9 sees your command:

                  The name of the command


                  The disk drive containing the file to be copied


                  The name of the file to copy


                  The disk drive that is to receive the new file


                  The name of the copy


copy /d0/hot5tuff /d1/hotcopy

 This command line tells OS-9 to copy a file named Hotstuff from your floppy disk Drive /DO to a second floppy Drive /D1. The file copy is given the new name, Hotcopy.

 You only need to know the name of the file you want to copy, on which disk it is located, and the disk on which you want the new copy. OS-9 manages the operation for you.

 Accessing Commands

OS-9 has two ways to access commands. Some commands reside on a disk. When you type the command name and press ENTER , OS-9 must look on the disk, load the program into the computer's memory, and then execute it.


Other commands are loaded into your computer's memory at startup, or you can load them into memory later. When you call a command that is in memory, it is executed immediately. There is no delay while OS-9 finds it on disk.


5-4
 Commands and Keys / 5
Commands from Disk

When you give OS-9 a command that it cannot find in memory, it looks for the command in the current execution directory. If it cannot find it there, it checks the current data directory. If it still cannot find it, the system issues Error Message #216, Path Name Not Found. If the command you want executed is in a directory other than the current directory, you must tell OS-9 where to find it. Remember, when initialized, OS-9 sets the CMDS directory of the system disk to be the execution directory.


For instance, suppose you booted your system using a diskette configured like the example we used in Chapter 4:


          ROOT DIRECTORY


            OS9Boot

            Startup


CMDS FAMILY SYS

 PLEASURE WORK

 mom mom
 dad dad

 joe

 doe

 5-5
 Getting Started With OS-9
When the system starts, the ROOT directory is the data directory, and the CMDS directory is the execution directory. Now, suppose you had a program named Expenses in the family directory:

 ROOT DIRECTORY

 OS9Boot
 Startup

 CFAMILY SYS

 expenses

 PLEASURE WORK

 mom dad joe

 mom dad joe

 (Remember that a program and a command are really the same thing.)

 You can now access (use) the expenses program in two ways. One way is to specify a pathlist from the ROOT directory to execute Expenses, such as:

    /d0/fami ly/expenses ENTER


Another way is to change the execution directory.

 Changing the Execution Directory

 To change the execution directory to the FAMILY directory, type:

    chx /d0/fami ly ENTER


Or specify a pathlist relative to the current execution directory, such as:

    chx . . /fami ly ENTER


To execute the Expenses program, you now only need to type

 expenses ENTER .

 5-6
 Commands and Keys / 5
However, after you change the execution directory, to use a command in the COMMANDS directory, you must tell OS-9 where to find it. For example, to format a new diskette in Drive /D1, type:

 /d0/cmds/format /d1
Changing the Data Directory

Suppose that the Expenses program keeps track of work and pleasure expenses for Mom, Dad, and Joe. Unless you tell OS-9 otherwise, it looks for data files in the current data directory, the ROOT directory. To tell OS-9 to look for data files in the PLEASURE directory, type:


chd family/pleasure

The slash between FAMILY and PLEASURE tells the system that PLEASURE is a branch of FAMILY. Subordinate directories and files are always separated from their parent in this way.


Now, when Expenses needs data, it knows to look in the PLEASURE directory.


Changing System Diskettes

Although it is preferable to leave the system diskette in place while the system is running, particularly with multiuser systems, there might be times when you need to use another diskette. Only remove the current diskette when the screen displays the OS-9 prompt, followed by the cursor. If you do remove the system diskette and begin to use another one, use the CHD and CHX commands to tell OS-9 where you want to be located on the new diskette. (For directions, see Chapters 2 and 6.) Those commands set both directory pointers, data and execution, for the new diskette.


While using a program or command, do not remove a diskette and insert another unless the program or command asks you to. -You can lose data, or entire files, if you do.


5-7
 Getting Started With OS-9
Video Display and Keyboard Functions

OS-9 has many features that expand the capability of the Color Computer's video display and keyboard.


      The video display has upper-/lowercase, screen pause, graphics functions, and 80 column displays if you have a monitor connected.


      t The mT key provides an alternate key function. Holding down mT while pressing another key sets the high order bit of the character pressed. That is, it adds 128 to the normal ASCII value produced by that key. Holding down nm while pressing any other key produces a graphics character on the standard VDG screen. If you are using windows, nm lets you produce international characters. (See OS-9 Windowing System Owner's Manual for more information).


      · The keyboard has an auto-repeat function. Holding down a key causes the character to repeat until you release the key. This function operates properly only when the disk drives are not in use by a program.


      You can deal with the video display and keyboard together as though they are a file. You can receive input from the keyboard and send output to the video screen using the device name /TERM.


Special Keys

The following keys and key sequences have special significance to OS-9.


    nn Produces graphic characters on a stan

    dard VDG screen or international

    characters with windows. Press mT

    char where char is a keyboard charac

    ter).

    CTRL A control key.

    BREAK Or Stops the current program execution.

    CTRL DE

    0 or Moves the cursor to the left one space.

    CTRL OH


5-8
                  Commands and Keys l 5


CTRL Q Generates an underscore character. The
 underscore displays as a left arrow.
 CTRL 0 Generates a left brace ({).
 CTRL ~ Generates a right brace (}).
 CTRL 0 Generates a tilde (').
 CTRL ID Generates a backslash ( \ ).
 CTRL BREAK Performs an ESCAPE function, and
 or CTRL c~ sends an end-of-file message to a pro
 gram receiving keyboard input. To be
 recoenized, CTRL BREAK must be the

 first thing typed on a line.

 SHIFT BREAK Performs a CONTROL C function by
 interrupting the video display of a pro
 gram. The program runs as a back
 ground task.
 CLEAR * Selects the next video window.
 SHIFT CLEAR * Selects the previous video window.

            * You must have established windows for this function key to have any effect. See "Using Windows" in Chapter 7.


CTRL CLEAR Toggles the keyboard mouse on and off:
 The keyboard mouse uses the arrow
 keys and the two function keys (Fl and
 F2) to simulate an external mouse.
 When keyboard mouse is on, the nor
 mal functions for the arrow and func
 tion keys is suspended.
 sHm for Deletes the current line.
 CTRL X~
 CTRL o~ Activates or deactivates the shift lock
 function.
 CTRL Q Generates a vertical bar ( 1 ).
 CTRL C D Generates an up arrow W.
 CTRL aQ Generates a left bracket ([).

                              5-9

Getting Started With OS-9
    CTRL s~ Generates a right bracket ( ] ).


              CTRL ~ Redisplays the last line you typed and positions the cursor at the end of the line, but does not process the line. Press eNTER to process the line, or edit the line by backspacing. If you edit, press cTR~ ~ again to display the edited line.


    CTRL 0 Redisplays the current command line.


    CTRL w0 Temporarily halts video output. Press

    any key to resume output.

    ENTER Performs a carriage return or executes

    the current command line.


5-10