THOMAS-CONRAD CORPORATION

TC6843 ARC-CARD/SE

Card Type             Network Interface Card
Chip Set              NCR 90C26
NIC Type              ARCnet
Network Transfer Rate 2.5Mbps
Topology              Linear Bus, Star
Wiring Type           RG-62A/U 93ohm coaxial
Data Bus              16-bit Mac SE

[Image]

                                CONNECTIONS

         Function            Label           Function            Label

  Header to transceiver       J1A      RG-62A/U 93ohm              J2
                                       coaxial connector

  Header to controller        J1B

                       EXTENDED RANGE CONFIGURATION

     Response Time         Recon Time          JP1              JP2

  »       74.7 uS            840 mS            Open             Open

          283.4 uS          1680 mS           Closed            Open

          561.8 uS          1680 mS            Open            Closed

         11118.6 uS         1680 mS           Closed           Closed

  Note: This setting should only be changed when the length of the ARCnet
  segments exceed 6000 meters.

                          NODE ADDRESS SELECTION

  Setting   SW1/1   SW1/2   SW1/3   SW1/4   SW1/5   SW1/6   SW1/7   SW1/8

    1       Off      On      On      On      On      On      On      On

    2        On     Off      On      On      On      On      On      On

    3       Off     Off      On      On      On      On      On      On

    4        On      On     Off      On      On      On      On      On

    5       Off      On     Off      On      On      On      On      On

   249      Off      On      On     Off     Off     Off     Off      Off

   250       On     Off      On     Off     Off     Off     Off      Off

   251      Off     Off      On     Off     Off     Off     Off      Off

   252       On      On     Off     Off     Off     Off     Off      Off

   253      Off      On     Off     Off     Off     Off     Off      Off

                                   Note:

  A total of 253 node address settings are available. The switches are a
  binary representation of the decimal memory addresses. SW1/8 is the
  Most Significant Bit and switch SW1/1 is the Least Significant Bit. The
  switches have the following decimal values: SW1/8=128, SW1/7=64,
  SW1/6=32, SW1/5=16, SW1/4=8, SW1/3=4, SW1/2=2, SW1/1=1. Turn off the
  switches and add the values of the switches to obtain the correct node
  address. (Off=1, On=0)

  Addresses 0, 254 and 255 are reserved and should not be used.