12/05/94

PURPOSE; TO CONTRUCT A PIGGY-BACK CARD FOR THE DIGITALKER/LCD INTERFACE.

TO THE WB6JHQ REPEATER CONTROLLER.

        1. RADIO SHACK PERF-BOARD PN. 276-158

        2. INSTALL TWO 40 PIN AND ONE 28 PIN WIRE-WRAP SOCKET.


                      TOP VIEW
            __________________________
           |  ____    ____    ____    |        CUT PINS OF SOCKETS TO 1/4":
           | |. 6 |  |. 5 |  |. 2 |   |        ----------------------------
           | |  8 |  |  4 |  |  7 |   |          6821 PINS: 2-17,23,40
           | |  2 |  |  1 |  |  2 |   |
           | |  1 |  |  0 |  |  5 |   |
           | |    |  |  4 |  |  6 |   |          54104 PINS: ALL
           | |    |  |    |  |____|   |
           | |    |  |    |           |
           | |    |  |    |           |          27256 PINS: ALL
           | |    |  |    |           |
           | |____|  |____|           |
           |  10K  _  ....... 14 PIN  |
           |  POT.| | ....... CONN.LCD|
           |______|O|_________________|

        3. CUT PINS ON SOCKETS PER LIST TO 1/4" LONG.
           LEAVE ENOUGH FOR 1 WIRE
        4. WIRE-WRAP 6821 TO 54104 AND 27256 PER SCHEMATIC.
           MAKE WIRES AS SHORT AS POSSIBLE.
        5. USE A 14 PIN FLAT CABLE TO CONN. LCD TO PIGGY-BACK BOARD.
        6. SOLDER PIGGY-BACK BOARD ON TOP OF 6821 OF CONTROLLER BOARD.
        7. CONNECT *PIA1 TO 74LS138 PIN 9.
        8. CONNECT SPK_OUT TO MIXER INPUT J8.
        9. CONNECT PIN 40 OF U22 (+8 VOLTS) TO INPUT OF 7805 OF CONTROLLER.
           (JUNCTION OF C21 AND PWR 10 WITH 7805)