There is a far easier way to construct a red box that doesn't require much knowledge of circuit board construction or soldering.
1. Buy a Radio Shack
(model 43-139) pocket phone dialer
2. Open it up
3. Replace the crystal (the silver tube-looking thing) with a 6.5536 Mhz. crystal. This will require solder
ing two connections. Deal.
4. Close it up
5. Save into memory five * (star) tones
Or if you own a gameboy
you can purchase a red box emulation cartridge on the net.
The red box still works, unlike it's blue box
breathren, because the payphone systems are still basically the same as they've always been. The only way the telco knows that you've put your money in is through a tone that's sent over the phone line. Newer payphones disable the mouthpiece, which is actually a good solution, but one that hasn't been implemented very much. The advent of ESS
effectively spelled the end of 2600
ing, but red box
ing is still going strong -- probably the reason Radio Shack
still sells the pocket phone dialers.