Installation Guide DigiBoard COM/Xi
Intelligent Asynchronous Serial Communications Boards 
90029100A 

Installing COM/Xi Boards 
Before you plug in the board... 
Write down the serial number of the processor board in the space provided. You 
will need it if you have to contact DigiBoard regarding the board. 
Several jumpers need to be set to configure the board's I/O address, dual
ported memory start address and IRQ line. 

Figure 13	COM/8i Board          
                      
  ---------------------------------------------------
 |       serial #  xxxx         J1 *  * J2 jumper    |
 |                                 *  *              |
 |                                                   |
 |                                                    
 |   J2  J3  J4  J5  -  J14  J15 J16 J17          DB78 <-- Connector 
 |  *** *** ***  **********  *** *** ***
 |___________________________        ___           __| 
                            |________| |___________| 
 
 
Jumper Settings 
The COM/Xi Processor board has three sets of jumpers which determine the I/O 
port address, the interrupt request (IRQ) line and the starting address of the 
board's dual-ported memory window.  See your software installation instructions 
for recommended address and IRQ selections. 
 
Memory Start Address_Jumpers J15, J16 and J17 
The COM/Xi board has 256K of on-board RAM which is accessible to the host 
computer through a 32K "window" in the host's memory map.  The 32K window 
is mapped into an unused block of memory address space in the area reserved for 
expansion boards (0C0000h-0DFFFFh).  There are four address ranges available 
for the COM/Xi: 0C0000h-0C7FFFh, 0C8000h-0CFFFFh, 0D0000h-0D7FFFFh and 
0D8000h-0DFFFFh.  Each COM/Xi board requires its own 32K block of 
addresses, and no other device may share these addresses.  While up to four 
COM/Xi boards can be installed in a system, this assumes that the entire 128K 
from 0C0000h-0DFFFFh is available. In practice, this is often not the case. EGA 
and VGA cards use memory addresses in this region, as do ESDI and SCSI 
controllers.  Also, the presence of 16-bit memory devices (such as 16-bit VGA 
cards) in this region can cause COM/Xi boards to fail.

Figure 14 shows the jumper settings for the four memory start addresses 
available on the COM/Xi board. 

Figure 14	J15-J17_COM/Xi Memory Start Addresses 

Pins 1 & 2 jumper left 2 pins     J  J  *
Pins 2 & 3 jumper right 2 pins    *  J  J

             J15          J16          J17    

C0000     Pins 2 & 3   Pins 2 & 3   Pins 2 & 3  
C8000     Pins 2 & 3   Pins 1 & 2   Pins 2 & 3
D0000     Pins 1 & 2   Pins 2 & 3   Pins 2 & 3  
D8000     Pins 1 & 2   Pins 1 & 2   Pins 2 & 3 

I/O Port Address_Jumpers J2, J3 and J4 
Each COM/Xi board must have a unique I/O port address.  This address must 
not be used by any other device in the system, including other COM/Xi boards. 
The I/O port address is determined by setting jumpers J2, J3 and J4 as shown 
below. 

Figure 15 	J2-J4_COM/Xi I/O Port Addresses 
  
             Jumper J2   Jumper J3   Jumper J4

100h	     Pins 2 & 3  Pins 2 & 3  Pins 1 & 2
110h	     Pins 2 & 3  Pins 1 & 2  Pins 2 & 3
120h	     Pins 2 & 3  Pins 1 & 2  Pins 1 & 2
200h	     Pins 1 & 2  Pins 2 & 3  Pins 2 & 3
220h	     Pins 1 & 2  Pins 2 & 3  Pins 1 & 2
300h	     Pins 1 & 2  Pins 1 & 2  Pins 2 & 3
320h	     Pins 1 & 2  Pins 1 & 2  Pins 1 & 2

Interrupt Request (IRQ) Line_J5-J14 
Jumpers J5-J14 are used to specify which IRQ line will be used by the board to 
interrupt the host. Each board must have its own unique IRQ selection, and that 
IRQ line must not be used by any other device in the system. Select the IRQ by 
placing a jumper across the pins of one of the jumpers J5-J14 as shown in
Figure 16. 

Many DigiBoard device drivers do not use interrupts.  If you are using one of 
these drivers (see the installation instructions for the device driver), the 
interrupts should be disabled (no jumper installed).  

Figure 16	J5-J14_COM/Xi IRQ Selection 
  
Disabled     No jumpers J5-J14 
  
IRQ2         Jumper on (J14)
IRQ3         Jumper on (J13)
IRQ4         Jumper on (J12) 
IRQ5         Jumper on (J11)
IRQ6         Jumper on (J10)
IRQ7         Jumper on (J9) 
IRQ10        Jumper on (J8)
IRQ11        Jumper on (J7)
IRQ12        Jumper on (J6)
IRQ15        Jumper on (J5)

NOTES_	The silk-screen numbers below J5-J14 do not line up exactly with 
the jumpers.  To ensure correct jumper placement, count from either end
of the row of jumpers. IRQs 10-15 can only be used if the board is plugged
into an AT (16 bit) slot. 

EPROM Size Jumpers_J1 and J2 
The I/O Mate (daughter card) has two jumpers, J1 and J2, which indicate the
size of the EPROM. The default positions for J1 and J2 are pins 1 and 2 (the
top two pins) connected.

The COM/Xi board is an 8-bit board, but is equipped with an AT-style dual edge 
connector to facilitate the use of IRQs 10, 11, 12 and 15. When using IRQs 2-7,
or no IRQ, the board may be installed in an XT (8-bit) slot, provided that
there is clearance at the end of the slot for the extra edge connector.