One batch file that you may find particularly useful is called AUTOEXEC.BAT. Every time you turn on your computer, MS-DOS looks for the AUTOEXEC.BAT file and automatically executes each of the commands.

When you install MS-DOS, it automatically creates an AUTOEXEC.BAT file for you. To create or modify the file, you can use the same programs that you use to create any other batch file (COPY, EDLIN, or a word processing program that can save a file as a text-only file). However, be sure to name the file AUTOEXEC.BAT and store it in the root directory of the hard disk or diskette from which you load MS-DOS.

See your MS-DOS Reference Manual for more information about your AUTOEXEC.BAT file.

Changing the Processor Speed

Your computer’s processor can operate at two speeds: high and low. High speed is 20 MHz and low speed simulates an 8 MHz processor speed. On high, the computer can access memory faster than on low. Your processor is set to operate at high speed unless you change the speed to low or set the speed to change automatically.

Note

When your computer is operating at high speed, the TURBO light on the front panel is illuminated. The TURBO light is off when your computer is operating at low speed.

You should use high speed for almost everything you do since your programs will work faster. However, certain application programs have specific timing requirements for diskette access and can run only at the slower speed. See the manual for your program to determine if this is the case.

4-2 Enhancing System Operations