+--------------+
                         |    Memory    |
                         +--------------+
                            ^   ^
                           /|\ /|\
                            |   |
                            |  +----------+
                            |  |  Memory  |
+----------+                |  | Address  |
|  Sense   |    +---------+ |  | Register |
| Switches |<-->| Control | |  | (MA) 12  |
|    6     |    +---------+ |  +----------+
+----------+     ^   ^   ^  |   ^   ^
                /|\ /|\ /|\ |  /|\ /|\
       +---------+   |   |  |   |   |            +----------+
       | +-------------+ |  |   | +----------+   |   Test   |
       | | Instruction | |  |   | | Program  |   | Address  |
       | |  Register   | |  |   | | Counter  |<--| Switches |
       | |     5       | |  |   | | (PC) 12  |   |    12    |
       | +-------------+ |  |   | +----------+   +----------+
      \|/             ^  |  |   |  ^   |
       V             /|\ | \|/  | /|\  |
      +---------+     |  |  V   |  |   |
      | Program |    +--------------+  |
      |  Flags  |    |    Memory    |  |
      |    6    |    |    Buffer    |  |
      +---------+    |   Register   |  |
                     |   (MB) 18    |  |
                     +--------------+  |
                      ^     ^      ^   |
                     /|\   /|\    /|\  |
                      |     |      |   |
              +-------)-----)------)---+
              |       |     |      |
              |   +---)-----)------)---+
              |   |   |     |      |   |
             \|/ \|/ \|/    |     \|/ \|/
              V   V   V     |      V   V
         +-------------+    |     +-----------------+
         | Accumulator |<---)---->| In/Out Register |
         |   (AC) 18   |    |     |    (IO)  18     |
         +-------------+    |     +-----------------+
          ^    ^      ^     |      ^   ^           ^
         /|\  /|\    /|\    |     /|\ /|\         /|\
          |    |      |     |      |   |           |
          +----)------+    \|/     +---)-----------+
               |            V          |
         +-----------+  +---------+   \|/
         | Test Word |  | In/Out  |    V
         | Switches  |  | Control |  +-----------+
         |    18     |  +---------+  | External  |
         +-----------+               | Equipment |
                                     +-----------+