LS05 pin 14 (Vcc) o      -------
                                                           |      |     |
            +--+--+---------------------+--+--+------------+------+-o 1 |
            |  |  |                     |  |  |           ===.1uF | +5V |
  -------- [R][R][R] 3x10K       3x10K [R][R][R]   LS05    |      |     |
  |      |  |  |  |                     |  |  |    pin 7 o-+------+-o 2 |
  | 12 o-+--+  |  |   3|\ 4             |  |  |    (Gnd)          | GND |
  | 17 o-+-----|--|----| >o-------------+--|--|--------------+    |     |
  |      |     |  |    |/        8 /|9     |  |     10 /|11  +----+-o 3 |
  | 15 o-+-----+--|--------------o< |------+--|------o< |----+    | SCL |
  |      |        |   1|\ 2        \|         |        \|         |     |
  |  9 o-+--------|----| >o-------------------+--------------+----+-o 4 |
  |      |        |    |/                            6 /|5   |    | SDA |
  | 11 o-+--------+----------------------------------o< |----+    -------
  | 10 o-+-+                                           \|          4-pin
  | 13 o-+-+--oGND                                              Connector
  | 25 o-+-+      ------------------ Part List --------------------------
  --------        | 1 - .1 uF capacitor   | 6 - 10K 5% resistors        |
  25-pin male D   | 1 - 4-pin connector   | 1 - 25-pin male D connector |
  connector to PC | 1 - 74LS05 open collector hex inverter              |
  printer port    -------------------------------------------------------