8253

Programmable Interval Timer

Pinout

DIP24
         +---\/---+
      D7 | 1    24| Vcc
      D6 | 2    23| *WR
      D5 | 3    22| *RD
      D4 | 4    21| *CS
      D3 | 5    20| A1
      D2 | 6    19| A0
      D1 | 7    18| CLK2
      D0 | 8    17| OUT2
    CLK0 | 9    16| GATE2
    OUT0 |10    15| CLK1
   GATE0 |11    14| GATE1
     GND |12    13| OUT1
         +--------+

Frequency

DIP24
Set reader to FREQ, put black probe to GND, red probe to 9,15,18 to measure CPU clock

Files

• 

  D8253C Datasheet