IBASE MB900 - Manual (Page 14)

INSTALLATIONS
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
Function
RS-232 RS-422 RS-485
Jumper
Setting
(pin closed)
JP1:
1-2
JP2:
3-5 & 4-6
JP3:
3-5 & 4-6
JP1:
3-4
JP2:
1-3 & 2-4
JP3:
1-3 & 2-4
JP1:
5-6
JP2:
1-3 & 2-4
JP3:
1-3 & 2-4
JP4: IDE DMA Mode Setting
JP4 Setting Function
Pin 1-2
Short/Closed
UDMA66 (default)
Pin 2-3
Short/Closed
Forced UDMA33
JP6: Clear CMOS Contents
Use JP6, a 3-pin header, to clear the CMOS contents. Note that the
ATX-power connector should be disconnected from the motherboard
before clearing CMOS.
JP6 Setting Function
Pin 1-2
Short/Closed
Normal
Pin 2-3
Short/Closed
Clear CMOS
10 MB900-R User’s Manual