Lesson 3 The Keyboard

Lesson 3 presents some of the special keys on the terminal keyboard and how they are used.

The terminal keyboard appears similar to the keyboard of an electric typewriter. Yet, only the arrangement of the alphabetic keys is identical.

This module does not attempt to define every key on the keyboard. Instead, it concentrates on those keys that are of most immediate value to the new user and those that may differ on various terminals.

You should read this lesson while you are sitting at a keyboard for the HP 2392 series or HP 700/92 and HP 700/94 terminals.




	NOTE: If you are using an HP Vectra™, an HP 150™, or some other terminal connected to an HP 3000 computer, your keyboard looks different, and some of the keys behave slightly differently. Read the documentation that came with your terminal to get more information about the operation of your keyboard.

The summary chart at the end of this lesson lists some of the special keys that might be on your keyboard. It also gives a brief description of their function.

Look at your keyboard now.

Figure 3-2 HP 2392 or HP 700/92 Keyboard

Figure 2-2 highlights the keys in the following discussions.

The return key

If you are accustomed to using a typewriter, you will discover that the Return key on a computer behaves quite differently. On some terminals, this key is labeled Enter.

On a typewriter, Return advances the paper one line and returns the carriage (or the typing element) to start a new line.

The Return key on a computer does much more than it does on a typewriter.

Sometimes labeled Enter, the Return key is the keyboard's main communicator with the computer. What you type appears on the screen. (There are a few exceptions. Passwords that you enter in response to a challenge from the system do not appear on the screen when you type them.)

But until you press Return, the computer is unaware of what you have typed.

Pressing Return sends to the computer those characters that are displayed on the screen and held in the terminal's memory area.

The Return key:

after a command name: tells the computer to execute the command
after a program name: tells the computer to start the program
in a document: ends one line of text and starts a new line
alone: scrolls the screen (and whatever appears there) upward, one line at a time

Backspace key

The backspace key ← or Backspace (figure 2-2) and the arrow left key [ltrif] (on the keypad) are two different keys, and they perform two different tasks. You will learn about the arrow keys later.

When you use ←, MPE/iX moves the cursor backward and removes characters from the terminal's memory one character at a time. Remember that the computer does not receive what you type until you press Return.

Using ← prevents the computer from ever receiving the characters that you backspace over, but the characters still appear on the screen.

As soon as you stop pressing ←, the computer waits for you to type in new material over the old letters that you deleted from the terminal's memory.




	NOTE: This deleting function of ← is invisible to you. The letters you backspace over still appear on the screen. But don't be fooled. When you use ←, the letter that you see above the cursor has been deleted. And so have all of the letters that appear to the right of the cursor.

You can type over those letters if you want to change or reenter them.
You can press Return to enter the letters that remain (those to the left of the cursor).

Numeric keys

The number keys ( 1 , 2 , 3 , 4 , and so on, above the letter keys and across the top of the keyboard) work the way they do on a typewriter.

There are three keys that are likely to cause confusion for some users who are accustomed to typewriters or who have never used a computer:

lower case "L":
The "l" key cannot be used to represent the number 1 (one) on the computer. They are not the same. If you want the number 1 (one), press 1 . If you want the letter "l" press L .
The letter "O":
The letter "O" or "o" cannot be used to represent the number 0 (zero). They are not the same. If you want zero, press 0 .
The Caps lock key.
This key turns all of the letters into capitals, but it does not force the shift of nonletter keys. For instance, when Caps lock is set, "a" is always rendered as "A"; however, "9" is not rendered as "(" (left parenthesis) but as "9". To get "(" you must hold down SHIFT9.

Numeric keypad

The number keys on the keypad on the right side of the keyboard also enter numbers. These keys are arranged like an adding machine or calculator. They are used for high-speed entry of numeric data (into a database, for instance).

On a Vectra™ keyboard, the keypad numbers are activated and deactivated by pressing the Num lock key.

Cursor control keys

These keys allow you to move the cursor around on the terminal screen:

[utrif]: Moves the cursor up toward the top of the screen.
[dtrif]: Moves the cursor down toward the bottom of the screen.
[rtrif]: Moves the cursor toward the right of the screen.
[ltrif]: Moves the cursor toward the left of the screen.
Home key: Moves the cursor as far upward and to the left as it can go. How far it can go depends on the limit of your terminal's screen memory.
ShiftHome key: Moves the cursor as far down as it can go. How far it can go depends on the limit of your terminal's internal memory.
Prev: (If there is one) moves the cursor up by one screenful of material — the cursor goes up, the material seems to go down. Prev is labeled Pg Up or Page Down on some keyboards.
Next: (If there is one) moves the cursor down by one screenful of material — the cursor goes to row one, column one of the next screenful of text. The material seems to go up. Labeled Pg Dn or Page Down on some keyboards.




	NOTE: You will not use the arrow keys for any of the modules in this tutorial. The arrow keys are recognized by some programs and not by others. Attempting to use the arrow keys in a program that does not recognize them can lead to confusion.

Function keys

The keys numbered f1, f2, f3 through f8 at the top of your keyboard are called Function keys. These keys correspond to the boxes at the bottom of your terminal screen. These function keys are also called softkeys because their function is not fixed (hard-coded), but can be changed, by the system itself or by an advanced user, to suit a particular purpose.

You will be learning more about the function keys in lesson 4, "Any Problems?"

Other special keys

The following is a summary of other special keys found on most Hewlett-Packard terminal keyboards:

Table 3-1 Other Special Keys

Key	Function
Clear Display	Clears the screen (and its memory) of anything displayed below and to the right of the cursor position.
Clear Line	Erases characters from the cursor position to the end of the line.
CTRL	Used with some special commands.
Del/Esc	Deletes a character/Sends a special command.
Delete Char	Erases a character at the cursor position.
Delete Line	Erases the line in which the cursor is found.
Extended Char	Switches special character recognition on and off.
Insert Char	Inserts a character at the cursor position.
Insert Line	Inserts a line at the cursor position.
Menu	Switches the softkey boxes on and off.
Next	Moves the display forward by one screenful.
Prev	Moves the display backward by one screenful.
Print/Enter	Prints what is on the screen. You must press SHIFTPrint/Enter to print what is on the screen.
Reset/Break	Interrupts the computer.
Select	In some applications tells the computer to "do" or "choose" this (whatever is highlighted).
STOP	Stops and starts the scrolling on the screen.
User/System	Switches between user-defined and system-defined softkeys.




	NOTE: BE AWARE: This discussion deals only with the way MPE/iX uses the keys on the HP 2392, HP 700/92, and HP 700/94 terminals. Other programs and other terminals may handle the key functions differently. If you run into difficulties, consult the documentation for the program or for the terminal that you are using.

Lesson 3 Exercises

Explain how the Return/Enter key on a terminal is different from the RETURN key on a typewriter.
Explain how the backspace, (←), is different from the backspace key on a typewriter.

Lesson 3 The Keyboard

Technical documentation

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