4016 DX  (250-5001)           Math Co-processor         Faxback Doc. # 1550

The math coprocessor socket is located on the CPU board, as illustrated in
the following diagram.

                            ┌─────────────────────────────┐
                        N ┌─┤ ┌─────────────────────────┐ │
                        M ├─┤ │                         │ │
                        L ├─┤ │                         │ │
                        K ├─┤ │      ┌───────────┐      │ │
                        J ├─┤ │    ┌─┘           └─┐    │ │
                        I ├─┤ │    │       .       │    │ │
            ┌────>      H ├─┤ │    │               │    │ │
            │           G ├─┤ │    │   .       .   │ ───┼─┼── Math Coproc
            │           F ├─┤ │    │               │    │ │   Socket
            │           E ├─┤ │    │       .       │    │ │
            │           D ├─┤ │    └─┐           ┌─┘    │ │
            │           C ├─┤ │      └───────────┘    ┌─┼─┼── Pin Socket 1
            │           B ├─┤ │                       │ │ │
            │           A ├─┤ │                       . │ │
            │             └─┤ └─────────────────────────┘ │
            │               └─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬─┘
            │                 └─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┴─┘
            │                  1 1 1 1 9 8 7 6 5 4 3 2 1                 
            │                  3 2 1 0
            │          
            │          
           ┌┼───────────────────────────┐
 CPU       ││  ┌───────┐   ┌───────┐    │
BOARD      ││  │       │   │       │    │
  │        │└─>│       │   │       │    │
  └───────>│   └───────┘   └───────┘    │
           │              ┌───┐┌───┐    │
           │              └───┘└───┘    │
           │              ┌────────┐    │
           │              └────────┘    │
           └─┬┬┬┬┬┬┬┬┬┬┬────┬┬┬┬┬┬┬┬┬┬┬─┘
             └┴┴┴┴┴┴┴┴┴┘    └┴┴┴┴┴┴┴┴─┘

WARNING: Incorrect installation of a math coprocessor can damage the
coprocessor, the CPU board, and/or the main logic board.

Read the instructions in this section completely before attempting to 
install your math coprocessor. You can also refer to the installation
instructions included with your coprocessor. Radio Shack Service Center
technicians will install the coprocessor if you choose not to do so 
yourself.

CAUTION: Before handling electrical components, touch a grounded metal 
object to release any static electric charge.

NOTE: Installing the 80387 will leave an extra row of socket holes around 
the outside of the socket.

1. Orient the math coprocessor so that the dot on the notched corner aligns
   with Pin Socket 1. (See the preceding illustration.)

CAUTION: Be sure that the math coprocessor is properly oriented before you
press it into its socket. Removal of this coprocessor requires a special IC
extraction tool.

2. Do not bend or touch the metal pins. Press the coprocessor into the 
   socket.  Correct installation will leave a gap between the socket and 
   the coprocessor.

CAUTION: Do not attempt to close this gap. Pressing the coprocessor too far
into the socket can damage the socket.

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