_______________________________
/                               \
|              _________________|___
|              \  1o 2o 3o  o   o  /  DB9
|               \  | o|7o| o  o   /   Soldering side view
|                \_|__|_||_______/
|                  |  | ||
|  ________________|__/ ||
| /  ___________________|/
| | /                   |
| | |                   |
| | |   ________________/
| | |  /
| | |  |  D3               R1      4.7V
| | |  `-->|---+-----+----/\/\-------+-------------------.
| | |   1N5819 |     |    47R        |                   |
| | |          |     |               |                   |
| | |          |     |          1C1  |16                 _ 4.7V
| | |          |     |        .------+------,         D4 ^ 400mW
| | |          |     |       2|     VCC     |            |
| | |          |     `--------|v+           |            |
| | |          |      C4     4|     MAX     |1           |
| | |          |   .--)|------|C2+  232  C1+|---         |
| | |          |   |  1uf    5|             |3           |
| | |          |   `----------|C2-       C1-|---         |
| | |          |            14|             |11          |
| | |          | C2        ---|232-01 TTL-11|---         |
| | |          _            13|             |12          |
| | |          @ 1uf       ---|232-11 TTL-01|---         |
| | |          |             7|             |10          |
|  `|----------|--------------|232-02 TTL-12|-------+----+---- MBUS
|   |          |             8|             |9  D5  |    |
|   `----------|--------------|232-12 TTL-02|----|<-'    |
|              |             6|             |  1N5819    |
|              |       ,------|v-   GND     |            |
|              |       |      `------+------'            |
|              |       |             |15                 |
|              |       |             |                   |
|              |    C3 @             |                   |
|              |       - 1uf         |                   |
|              |       |             |                   |
\______________|_______|_____________|________,__________/---- GND
                                              V

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