Intel MB865 Configuring the CPU Frequency, COM2, RS-232, Function, RS-422, RS-485, Setting

INSTALLATIONS

Configuring the CPU Frequency

The MB865 motherboard does not provide DIP switches to configure the processor speed (CPU frequency). The CPU frequency and processor side bus of the processor can be automatically detected by the motherboard.

JP1, JP2, JP3: RS232/422/485 (COM2) Selection COM1 is fixed for RS-232 use only.

COM2 is selectable for RS232, RS-422 and RS-485. COM3 and COM4 are fixed for RS-232 use only. The following table describes the jumper settings for COM2 selection.

COM2	RS-232
Function
	JP1:
Jumper	1-2
Setting	JP2:
(pin closed)	3-5 & 4-6
	JP3:
	3-5 & 4-6

RS-422

JP1:

3-4

JP2:

1-3 & 2-4

JP3:

1-3 & 2-4

RS-485

JP1:

5-6

JP2:

1-3 & 2-4

JP3:

1-3 & 2-4

JP4: Clear CMOS Contents

Use JP4, a 3-pin header, to clear the CMOS contents. Note that the ATX-power connector should be disconnected from the motherboard before clearing CMOS.

JP4

Setting

Function

Pin 1-2	Normal
Short/Closed
Pin 2-3	Clear CMOS
Short/Closed

10 MB865 User’s Manual