- Bypassing the Stupid IC -

In Chapter 15 of my book I talk about how some Atari 2600's have an annoying 8-DIP IC located outside the "4-inch square" area of the board. This IC (and its resistor and capacitor) has to be rewired to the 4" square to keep the Atari working.

Since then I came across some old schematics (and studied the boards WITHOUT that IC) and found a way to make the same circuit that IC did without actually hooking it back up.

Parts You'll Need:( Pretty simple!)

   4.7k uf capacitor (Digi-key part # 4065PHCT-ND )
   24k ohm resistor (Digi-key part # 24KQBK-ND )

What to do: (Also pretty simple)

You'll actually be recreating the circuit found on Atari boards that don't use the IC.

1) Connect one end of the 24k resistor to +5 volts on the Atari board (see book for details)

2) Connect the other end of the resistor to the POSITIVE lead of the 4.7 uf capacitor. Usually this is the lead without a black band near it. (As with the above-mentioned Digi-key capacitor) Some capacitors also have a white stripe on one side, indicating the negative lead. Basically, the lead with NO stripe or marking is the positive one. Check the resistor's PDF file or packaging to make sure.

3) Connect the negative lead of the capacitor to the Atari's ground.

4) Finally, connect the positive lead of the capacitor (which also has the resistor connected) to pin 1 of the center chip on the Atari, the CPU. Here's which pin it is:

Note: Shown is an Atari board that doesn't have the annoying IC. As you can see, it already has the 4.7 uf capacitor built-in. There's an empty space there on the IC-using boards, so you can place your capacitor there so it won't get in the way of anything else in your project.

And that's it! The IC is now permanently orphaned off the Atari board. (Somebody call Charles Dickens)

Note 2: I have only tried this with the exact resistor/capacitor values mentioned (4.7 uf and 24k) I do not know if it will work using slightly different values... if it does let me know. But your best bet is to use the exact values.

Have fun!