operation and maintenance of a microcomputer can be
Keyboards come in many shapes and sizes, have
different numbers and arrangements of keys, differ in
respect to touch, and have special keys to allow you to
communicate specific software commands. Most
manufacturers have designed their keyboards as
separate devices so you can place them wherever it is
convenient (even in your lap). Other manufacturers
have designed their keyboards into the display/monitor
device or system unit.
Refer to figure 3-9 for an
illustration of a typical keyboard used with a PC.
The important things you need to know about
keyboards are the types of keys and the function and the
placement of each key. All keyboards have the
alphabetic characters (upper and lower case), numbers,
and some special characters. In addition, keyboards
have special function keys and control keys that are
defined by the operating. system or the program. It is
important to remember that any key or combination of
keys can be assigned special meaning by a program.
Therefore, the keys may have different meanings and
functions depending on the program you are using.
Once again, we remind you, read all the documentation
that comes with each program and with the computer
system. The keyboard has the following three levels of
controls and indications:
Initiate computer operations
Control computer operations
In addition to a keyboard, a microcomputer may
have a mouse. The mouse can be used with the monitor
as a controlling device after the computer has been
booted and the operating program has been initialized.
The operational program must be specially designed to
interface with a mouse.
Teletypes can be used as input/output communica-
tions consoles (IOCCs). They are used primarily as
means of inputting information to the computer and
receiving information from the computer. Teletypes
have a keyboard for inputting and a printer for
Once you have loaded the programs/
software (operational or maintenance) into the
computer, an IOCC or terminal of control (TOC) is used
to initialize the programs and communicate with the
computer when operating during operations or
You use the keyboard to give the
computer commands and parameters and the printer
portion to repeat back commands and parameters and
provide status of equipment or software and test
The commands used to communicate with the
computer are specific to the operating system and the
operational or maintenance programs. You can find the
Figure 3-9.Example of a typical keyboard used with a PC.