•Math coprocessor clock speed. If you or your dealer installs an 80287 math coprocessor, you may need to set the jumpers for a different clock speed. The jumpers determine the speed of the coprocessor.

As it is easy to damage a math coprocessor, you should have your dealer install it for you. In addition to checking the jumper settings, you or the dealer should also use the diagnostics’ Setup program to change the settings in the CMOS RAM, and use the System Diagnostics program to test the coprocessor.

Table A-2 shows the functions for the jumpers on the main circuit board.

Table A-2. Main circuit board jumper settings

 

Jumper

 

number

 

Function

 

1

2

3

4

5

 

 

A

 

 

 

 

1 wait state for EPROM access •

 

B-

 

 

 

 

2 wait states for EPROM access

 

 

A

A

 

 

1 wait state for 16-bit option card *

 

 

 

 

 

 

B

A

 

 

2 wait states for 16-bit option card

 

 

A

B

 

 

3 wait states for 16-bit option card

 

 

B

B

 

 

4 wait states for 16-bit option card •

 

 

 

 

A

A

Set coprocessor clock at 8 MHz *

 

 

 

 

B

B

Set coprocessor at 1/3 of CPU speed

 

* Default setting

To access the main circuit board jumpers, you must remove the memory card from the computer, as described above. Do not try to access the jumpers while this card is still in the computer.

Figure A-5 shows the locations of jumpers J1-J5 on the main circuit board. Refer to Table A-2 above to set them as needed.

When you finish changing the jumpers, carefully replace the memory card in its slot and secure it with the retaining screw.

User’s Guide

A-5