CNET TECHNOLOGY, INC.

CN120A, CN120AB, CN120AT, CN120SBT CN120ST, CN120TP

NIC Type      ARCnet
Transfer Rate 2.5Mbps
Data Bus      8-bit ISA
Topology      Star

              Linear Bus
Wiring Type   RG-62A/U 93ohm coaxial

              Unshielded twisted pair
Boot ROM      Available

[Image]

                               NODE ADDRESS

  Node   SW2/1    SW2/2   SW2/3   SW2/4    SW2/5   SW2/6    SW2/7   SW2/8

   0      N/A     N/A      N/A     N/A     N/A      N/A     N/A      N/A

   1      On      Off      Off     Off     Off      Off     Off      Off

   2      Off      On      Off     Off     Off      Off     Off      Off

   3      On       On      Off     Off     Off      Off     Off      Off

   4      Off     Off      On      Off     Off      Off     Off      Off

  251     On       On      Off     On       On      On       On      On

  252     Off     Off      On      On       On      On       On      On

  253     On      Off      On      On       On      On       On      On

  254     Off      On      On      On       On      On       On      On

  255     On       On      On      On       On      On       On      On

  Note:Node address 0 is used for messaging between nodes and must not be
  used.

       A total of 255 node address settings are available. The switches
       are a binary representation of the decimal node addresses. Switch
       1 is the Least Significant Bit and switch 8 is the Most
       Significant Bit. The switches have the following decimal values:
       switch 1=1, 2=2, 3=4, 4=8, 5=16, 6=32, 7=64, 8=128. Turn on the
       switches and add the values of the on switches to obtain the
       correct node address. (On=1, Off=0)

                                 BOOT ROM

                 Setting                                JP1

  »               Disabled                             Open

                   Enabled                            Closed

                                CABLE TYPE

                  Type                                  JP3

  »         RG-62A/U 93ohm coaxial            Pins 2 & 3, 5 & 6 closed

           Unshielded twisted pair            Pins 1 & 2, 4 & 5 closed

                            ONBOARD TERMINATOR

                Setting                                 JP4

  »               Disabled                       Pins 2 & 3 closed

                   Enabled                       Pins 1 & 2 closed

            INTERRUPT SELECTION

         IRQ                   JP2

         2/9           Pins 9 & 10 closed

          3             Pins 7 & 8 closed

          4             Pins 5 & 6 closed

          5             Pins 3 & 4 closed

          7             Pins 1 & 2 closed

                  BASE MEMORY ADDRESS & BOOT ROM ADDRESS

  Base Address    Boot ROM    SW1/1    SW1/2    SW1/3    SW1/4     SW1/5
                  Address

      C0000h      C2000h       On        On       On       On       On

      C4000h      C6000h       On        On      Off       On       On

      CC000h      CE000h       On        On       On      Off       On

  »   D0000h      D2000h       On        On      Off      Off       On

      D4000h      D6000h       On        On       On       On       Off

      D8000h      DA000h       On        On      Off       On       Off

      DC000h      DE000h       On        On       On      Off       On

      E0000h      E2000h       On        On      Off      Off       Off

                             I/O BASE ADDRESS

       Address             SW1/6             SW1/7             SW1/8

           260h              On                On               On

           290h             Off                On               On

  »        2E0h              On               Off               On

           2F0h             Off               Off               On

           300h              On                On               Off

           350h             Off                On               Off

           380h              On               Off               Off

           3E0h             Off               Off               Off

                             DIAGNOSTIC LED(S)

    LED       Color        Status                   Condition

   LED1        Red           Off                 Power is not on

   LED1        Red        Blinking                Network error

   LED1        Red           On                    Power is on

   LED2       Green          Off                Data is not being
                                              transmitted/received

   LED2       Green          On                   Data is being
                                              transmitted/received