68681

Dual Asynchronous Receiver / Transmitter

Pinout

DIP40
         +---\/---+
     RS1 | 1    40| Vcc
     IP3 | 2    39| IP4
     RS2 | 3    38| IP5
     IP1 | 4    37| *IACK
     RS3 | 5    36| IP2
     RS4 | 6    35| *CS
     IP0 | 7    34| *RESET
    R/*W | 8    33| X2
  *DTACK | 9    32| X1/CLK
    RXDB |10    31| RxDA
    TxDB |11    30| TxDA
     OP1 |12    29| OP0
     OP3 |13    28| OP2
     OP5 |14    27| OP4
     OP7 |15    26| OP6
      D1 |16    25| D0
      D3 |17    24| D2
      D5 |18    23| D4
      D7 |19    22| D6
     GND |20    21| *IRQ
         +--------+

Frequency

DIP40
Set reader to FREQ, put black probe to GND, red probe to 32 AND 33 to measure CPU clock

Files

• 
  m68681 Datasheet