Entering 20Mhz Turbo Mode; Softwareturbo Switch; Hardware Turbo Switch; Alternate Use Of Both Switches - Datatech Enterprises Apex 386SX/20 User Manual

6-2 Entering 20MHz Turbo Mode

The main advantage of your mainboard over ordinary PC/AT main-
boards is its dual clock system. This innovation makes it possible for
your computer to operate at either of two clock speeds: 10MHz or
20MHz.
Entering 20MHz Turbo Mode
Your system supports both a software and hardware switch to toggle
between 10MHz and 20MHz (Turbo) modes. The two switches are set
up using jumper J3 and are mutually exclusive. You must choose either
software or hardware if you are setting up the board yourself.
Software Turbo Switch
When jumper J3 is covered with a jumper cap or is connected to a
closed hardware Turbo switch, the speed can be toggled between
Turbo and Normal from the keyboard. The clock speed when you turn
the system on will be 10MHz (or 20MHz). To switch the speed to
20MHz (or l0MHz), do the following: press and hold down the control
<Ctrl> and alternate <Alt> keys on the keyboard while you press the
minus <-> key. The Turbo LED on your panel, if you have one, will light.
For more information on the Turbo LED, refer to the Connectors
section.

Hardware Turbo Switch

If your hardware Turbo switch is connected to pins one and two of
jumper J3, pushing the switch on and off will toggle between 10MHz
Normal mode and 20MHz Turbo mode.

Alternate Use of Both Switches

Both the hardware and the software switches may be used alternative-
ly, but this is not advised because you may become confused about
the mode of operation. When using both switches alternatively, the
Turbo LED will be the only accurate indicator of the actual mode: the
LED will be on in Turbo mode and off in Normal mode.
Chapter 6: Appendix
9