Commodore 128D - Page 196

The Command
Line
CP/M 3.0 performs tasks according to specific commands that you
type at your keyboard. These commands appear on the screen in
what is called a command line. A CP/M 3.0 command line is com
posed of a command keyword and an optional command tail. The
command keyword identifies a command (program) to be executed.
The command tail can contain extra information for the command,
such as a filename or parameters. The following example shows a
command line.
A>DIRMYFILE
Throughout this chapter, the characters that a user would type are in
slanted (italic) bold face type to distinguish them from characters
that the system displays. In this example, DIR is the command key
word and MYFILE is the command tail. To send the command line to
CP/M 3.0 for processing, press the RETURN key, as indicated in
this book by the HMUHNi symbol.
As you type characters at the keyboard, they appear on your screen.
The cursor moves to the right as you type. If you make a typing error,
press either the INST/DEL key or CTRL-H to move the cursor to the
left and correct the error. CTRL is the abbreviation for the CONTROL
key. To specify a control character, hold down the CTRL key and
press the appropriate letter key. (A list of control characters and their
uses is given in Section 13.)
You can type the keyword and command tail in any combination of
upper-case and lower-case letters. CP/M 3.0 interprets all letters in
the command line as uppercase.
Generally, you must type a command line directly after the system
prompt. However, CP/M 3.0 does allow spaces between the prompt
and the command keyword.
Types Of Commands
CP/M 3.0 recognizes two different types of commands: built-in com
mands and transient utility commands. Built-in commands execute
programs that reside in memory as a part of the CP/M operating
system. Built-in commands can be executed immediately. Transient
utility commands are stored on disk as program files. They must be
loaded from disk to perform their task. You can recognize transient
utility program files when a directory is displayed on the screen
because their filenames are followed by a period and COM (.COM).
Section 14 presents lists of the CP/M built-in and transient utility
commands.
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USING CP/M MODE—Introduction to CP/M 3.0
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