FPU addition

Froating point processing unit (FPU) substitute for CPU to carry out an operation at high speed. But there is no meaning when the application software does not require FPU. So, you should examine whether you add FPU on your logic borad or not for your purpose.
The table shows the result of benchmark test of Color Classic 2 with FPU (Norton Utilities-System Info).

FPU additon
ColorClassic2 030/33MHz2.9323.1
PowerBook540c 040/33MHz3.19

Color Classic 030 with FPU has been accelerated approximately 8-times as compared with the FPU-less model. 030-FPU operates faster than 040non-FPU. It may be more effective to add FPU than the upgrade to 68LC040, when the applications which you use often make use of FPU processing.

You can't add FPU to LC575 logic board.
You must exchange 68LC040 for 68040 including FPU, in this case.

As you can see on this photo, there is a socket on logic board of Color Classic. This is the socket for FPU.

Directing arrow is seen at the socket (some has no directing arrow). The corner pointed by the arow is cut into triangle. So, you never fail into insertion of FPU direction.

FPU used in this machine is MC68882.

You should pay attention to movement frequency of wave. FN**A following pattern number shows movement frequency of wave. Color Classic needs FN16A or over, and ColorClassic2/Performa275 need FN33A or over.
FPU is installed by pushing into the socket with putting the direction. After that, processing speed may be accelerated, when application is corresponding.

It's very easy :-)