During this time, we were on a number 5 crossbar exchange, and was primarily mechanical in operation. Also, we had manual operators at that time, where each city would have their own operators. Now, when you dial operator, she could be across the country.

When sending MF tones, they had to also send an "Open" tone called "KP" or Key Pulse, apparently to notify that a phone number is to follow. After dialing the number, a "ST" or "Start" tone would have to be sent, thus informing the distant equipment that the number was complete and to "Start" processing the call.

Also, area codes would ALWAYS have a zero or a 1 as the 2nd digit (Not true now, of course). Also, the first digit of an area code would NOT be a 1 or a zero. Patterns started to show, and it became obvious that trunking numbers would start with a 1 or a zero, and it wasn't long before I discovered that one could reach an operator by dialing "121", Information "131", and a special routing info operator "141". So, dialing KP-121-ST would ring an "Inward" operator that is supposed to handle incoming calls into a specific city.

For instance, to reach New York operator, one would dial KP-212-121-ST. 212 being New York. I often wondered what an operator would dial to reach an operator in a distant city. Next, I learned that by dialing KP-141-ST, I would get a route/rate operator and can ask her to give me operators routing to anywhere in the world. I would say "Operators routing for Fresno" and she would say "209+042+". It didn't take me long to realize that I would dial KP-209-042-121-ST to reach a Fresno operator.

With this information, I started mapping out the phone system, discovering all sorts of special internal trunking numbers like "Test board" KP-101-ST and even a loop KP-104-ST, among other "Secret" numbers.

I should point out that none of this works today, because all that equipment that uses these internal codes have all been replaced with digital equipment... In other words, DON'T TRY THIS AT HOME, FOLKS!!

One interesting discovery that Jimmy found was this special number in Vancouver. It was possible to dial 604-2111 (using a blue box of course, or operators console). It turned out that if anyone ELSE did the same thing, it would be a very clear conference call with unlimited (well, not really!!) number of people that can get on.

I would "record" the "KP-604-2111" and give the tape to Dennie and others so they could get on without a tone generator or MFer. Naturally, Jimmy and Dennie wanted me to build them one, but I didn't want to be responsible if they got busted for using it. I felt that as long as I wouldn't use it to make FREE calls, and only restricted it to dialing internal codes, I wasn't intentionally ripping them off.

It wasn't long before I realized that if I dialed a lot of 800 numbers, which actually were tabulated (but wouldn't show up on your bill), someone might notice an unusual amount of 800 calls.

During that time period, very few people know of this fatal weakness in Ma Bell, so it took about a year before someone got busted or caught using a blue box.