Foreword

The Falcon is quite a powerful computer even today, and the atari market continious to thrive. A standard Falcon can in some respects still be compared with the powerful PC's of today, the reason is simple; The streamlined programs.
Luckily the programs evolves and become stronger, and more and more programs makes use of the extra power a math-processor can provide. That's what this page is all about; to show you a cheap way to speed up your Falcon.

Yours truly
Geir Øyvind Vælidalo

Disclaimer

Equiment:

• A PLCC MC68881/882 FPU
• Soldering-iron (~15W)
• Solder
• Plier and a wire cutter
• Various screwdrivers
• One quartz-oscillator
• a Green wire
• a Red wire
• a Black wire
• A multimeter
• Possibly one Heat Sink for the FPU.
  

How fast?

First of all, buy an FPU you can afford. Because the CPU and the FPU work asynchronicly, you can freely choose the speed of the FPU. I know that it's possible to have the FPU operating at up to as much as 2.5 times its original speed due to though selection criterias at Motorola. I had a 20MHz running at 50MHz for a long time until I bought myself an Afterburner!
This mean that you can have a 16MHz FPU running at 40MHz, or a 32MHz at a stunning 80MHz!!!

	FPU      x2.5     My Advice
       16MHz     40MHz    32-40MHz
       20MHz	 50MHz    40-50MHz  w/Heat-sink
       32MHz     80MHz    64-66MHz  1) w/Heat-sink 
       40MHz    100MHz      <80MHz  1) w/Heat-sink
       50MHz    125MHz      <100MHz 2) w/Heat-sink
	

Open the lid

Unscrew all the screws, remove all metal shielding. To be able to remove the power supply, you must remove ALL metal shielding! You must also remove the keyboard, floppy and IDE-disc (if present).

Locate socket

The FPU's PLCC-socket, marked U33 on the motherboard, is right beneath the power supply. If you don't have a FPU installed, this should be empty, but if there's one allready you must take the FPU out of the PLCC-socket. Be carefull!!! Try to avoid thouching the legs, because if your body is charged, you could easily destroy some of the delicate cmos technology inside the FPU-chip!

Prepare Socket

Now you must find pin 11 on the FPU-socket (U33). Pin 10 are marked on the motherboard in the upper left corner of the socket, and pin 11 are the one right beneath it. This pin (11) must be totally isolated. I simply removed it, but I guess it might be possible to use some tape to cover it completely. Just remember to isolate it totally, all the way down to the motherboard.

The MC6888X

When the socket is adequately prepared, you have to locate pin 11 on the FPU itself. Find the dot on the FPU and hold it so the dot points away from you. The dot marks pin 1. Count counter clockwise and you'll find pin 11 as the second pin on the left side of the chip.

Green wire

Now you must solder the green wire wire to pin 11. Remember that the FPU must fit into the socket afterwards, so you must solder as high up on the pin as possible and use as little solder as possible.
The other end of the green wire must now be soldered to pin 8 on the quartz (see figure below!)

Black wire

Red wire

The red wire must be soldered to pin 14 on the quartz and to a nearby +5V. The easiest one would be the positive-pole of the same capacitor as mentioned above. This will provide a reliable source.
Place the quartz as near the FPU as possible. It's advicable to fit it with some double sided tape and use some electro tape on the legs to prevent short-cuircuting when replacing the PSU, floppy, HD and metal casing.

Plug in the FPU

Place the motherboard on a flat surface and insert the FPU in the socket. Press firmly on the four corners of the FPU until it clicks into place. The FPU should now be at the same height as the socket itself.

Finished!

Well, that's mostly it. Put back the power supply, floppy, HD and the rest of the stuff and you're finished!