Hacker Perspective: John Harrington (W5EME)

I'm not sure I qualify for the word "hacker" anymore.

I'm pushing 70, now, and although I read and enjoy 2600 any time I see it at Barnes & Noble, I hardly ever see anything I would rush out and try.

My hacking days started at about age nine or ten, right after (((World War II))).

I was interested in anything electrical or mechanical, and I left a trail of disassembled clocks, toys, and other interesting things wherever I was.  I smashed mercury batteries with a hammer (state of the art, back then) to collect the tiny droplets of mercury.

With pliers, I twisted the lead nose of a bullet out, to get the smidgen of gunpowder inside.

Back then, you could go to any chemical supply house and purchase any chemicals you wanted if you had the cash.  I once bought a canister of ether to see how much it took to put neighborhood animals to sleep.

Yes, the clerk sold a little kid a canister of ether.  Those were simpler, more trusting times.

I bought gallons of nitric and sulfuric acid to see what they would attack and how long it took.  One thing that caught my eye was the fact that nitric acid really attacked copper pennies: first it cleaned them up and made them a reddish color, then it would start eating away at the copper.

If you let them soak awhile, they would actually reduce in size down to the approximate size of a silver dime.  A light flashed inside my head... for months, I had been rubbing silver coins with mercury to make them bright.

The mercury coating made them slippery, too, just like they were greased.  Could a coating of mercury be rubbed on the acid-treated pennies to make them look like dimes?  The answer was yes, much to my delight.

I made a pocketful of "dimes" and proceeded to see if they would pass scrutiny with clerks at stores.  Usually, they did.

I also found they worked well in many coin-operated machines.  Back then, you got three three-cent stamps and a penny change for a dime in a coin-operated postage machine.  I could get three-cent stamps and a penny back for one of my trick pennies - pure profit.

The city buses collected fares in an elaborate gadget in which you dropped your 15-cent fare into a slot and it then fell onto a little platform.

The bus driver looked through a little window to make sure you had put in the right amount, flushed them into his coin box, made change if necessary, and you found a seat.

Two of my shiny, almost right-sized pennies fooled every bus driver I ever tried it on into thinking I had inserted two dimes, and gave me a nickel change!  Coke machines accepted the fake dimes, gave me a nickel Coke, and a nickel change.

For weeks, I was the richest kid in school.  I even sold my fake dimes to my friends for a nickel, and we both walked away happy.  Then, one of my friends had a bad experience at a store when he tried to buy a bicycle.

This terrified me so much I got out of the fake dime business for good.

I was delighted when I discovered the rotary dial telephones of the day dialed by the very short interruptions to the line which the old rotary dials produced.

Dial a "3," and the line got interrupted three times.

I badly wanted a lineman's handset, but of course had no way to obtain one.  I took an old handset, hooked up the earphone, carbon mike, and a normally-closed push button in series and stuffed all that back in the plastic handset shell with a cord equipped with alligator clips.  Presto - lineman's handset.

You clipped on a live telephone pair, got a dial tone, then dialed your number by mashing that push button switch, quickly, the number of times needed for that digit, then doing the rest of the number the same way.

It took some practice, but I got very good at it.

Upon reflection today, I think the reason I was so successful in dialing with a push button was that the timing specifications had to be so relaxed to cope with variations in the speed the old rotary dials returned when you dialed a number and let loose of the dial.  The line interruptions occurred on the return stroke and some dials were much faster than others.

Our telephone company in those days had climbing pegs on nearly every pole.

I guess the age of litigation had not yet arrived and companies didn't have Safety Managers to take the fun out of everything.  It was not unusual for me to climb a pole, open the unlocked box at the top, and hunt around for a dial tone with my alligator clips.

I learned quickly, though, to respect the ringing voltage that was sent over the pair to ring the bell on an incoming call.  Later, I read somewhere it was about 100 volts AC, at 20 cycles per second, generated at the central office by a big motor-generator set.

Never got blown off a pole, although I got the pee willy knocked out of me a few times by that big central office generator.

One wonderful hack we learned (we didn't know the word "hack" back then) was that on the payphones, you got a dial tone and could dial out when any part of the microphone circuit was grounded momentarily.

I soldered an alligator clip on one end of about a foot of stranded wire, and a safety pin on the other.

If you clipped the alligator clip on the finger stop of the rotary dial, you had your ground.  Then you poked the sharp end of the safety pin through a hole in the handset, right over the carbon mike.  You had to penetrate a little rubber cover (probably there to keep spittle out of the mike) and probe around.

Soon your grounded pin would contact the mike circuit, and you would hear a beautiful dial tone.

Put away your clip, wire, and probe, and make your free call.  Soon I learned exactly where to probe the mike to make contact quickly, and the elapsed time to get a free dial tone was just a few seconds, with no damage to the equipment.

A lesson learned the hard way was to be sure to close the safety pin before putting your little jumper cable in your pocket.  You didn't forget again.

Later, in high school, being interested in electronics (ham radio operator, etc.), I realized that the hearing aids of the day were very high-gain amplifiers with a mike.

My paternal grandmother had one.  She was a wonderful old lady, and let me examine hers once.

I discovered that there were three sub-miniature tubes in there, and a big 30V "B" battery, as well as a mercury cell which was the filament supply.  My grandmother told me she had to replace the filament battery at least daily, but the "B" battery lasted at least two weeks.

The mike was in the big box with the tubes and batteries, and you put it in a pocket with the earphone wire stretching up to your ear.  Most users tried to conceal the earphone wire by running it cleverly inside clothing, but I could spot a wire a mile away.

Naturally, after seeing inside the hearing aid that one time, I decided I was an expert.  Also, I wanted a couple for myself to experiment with.

So after school the next day, I went to every hearing aid store in town, offering my services as an expert hearing aid repairman.  Some stores had their own repairman, and some sent the unit back to the factory for repair, but when I hit the Beltone store, I got hired on the spot!  It seemed the lady who owned the place was a recent widow and her husband had been the repairman.

She was looking for a new repairman and I happened to drop in at just the right time.  She immediately gave me a dozen or so units to fix.

She was under time pressure because these hearing aids belonged to customers and she had the policy of loaning out a unit while the customer's was in the shop.  She had run out of loaners and was forced to loan out new units!

I fixed a few that afternoon (mostly corrosion on the battery contacts and a blown tube or two, as I recall) and she was very pleased.  She had a large collection of old units, trade-ins, and junked units which she gave me to take home.

She even threw in a few "B" batteries and mercury filament cells of various types.  I worked after school every day until all the repairs were cleaned up, then dropped off to a couple of days a week.  I fixed up most of the junkers she gave me until I had about 15 or 16 nicely working units.

Like many kids of the day, when I was much younger, I had built several crystal sets.

They worked O.K., but were not very loud and required a big antenna to work at all.  I hooked up a crystal set to the hearing aid mike input, and wow!

It was loud in the earphone and a strong station would come in with just a two foot antenna!  Perfect for covert listening during boring classes at school!

I built a tiny crystal set from a diode and a "loopstick" coil and attached it to the hearing aid.  Next day at school, it was a resounding hit.

Nobody had ever seen such a small radio, as transistor radios were not yet available.  Everyone wanted one.

Naturally, I started taking orders, for about $15 each as I recall, and sold out that same day.  After filling the orders, I still made money selling batteries for a few weeks until the school officials cracked down and warned students that anyone wearing a "hearing aid" during classes had to bring a note from home.

There are probably fewer opportunities today to get into mischief than in the glory days of the 1950s or 1960s, and most likely today would involve computers.

I like computers as much as anyone, I guess, and, in fact, built my first one back in 1972 from components, using an Intel 8008 microprocessor with a blazing 50 kHz clock.

All software was hand-assembled in the binary machine language of the day.  No C++ back then, or even a decent BASIC.  No mass storage for the average person, unless you had an ASR-33 teletype.

The teletype would save data at a whopping 10 CPS speed on paper tape.  If you had a decent sized program to load, you inserted the paper tape into the reader, then went out for lunch.  When you got back, your program might be finished loading.

We didn't mess much with online computers back then, but I will admit to playing the game ADVENT for hours on a certain Honeywell mainframe computer as an uninvited guest via a 300-baud acoustic modem.

I doubt if you can find a telephone pole today with foot pegs to climb, or find a chemical distributor who would sell a kid nitric acid over the counter, for fear of a lawsuit.

But, for those curious folks who are interested in how all things electrical and mechanical work - or can be retasked, there are still some fun things to do.

Get a subscription to Make Magazine.  Make is full of interesting projects from which you can get ideas.

I got my first set of lockpicks from a locksmith years ago, but Make sells them for a few bucks if you don't know a locksmith who will order you a set.

Look at ordinary everyday things to visualize how they can be hacked into something fun or useful.  Here's a simple example: Buy an old or scrapped electric wheelchair at a flea market or tailgate sale.

I have seen several for as low as $20.  Fix it, then radio remote control it.  You can buy a new 2.4 GHz RC transmitter and receiver set today for $100.  Imagine the fun as you run your wheelchair down a city street, seemingly out of control, with no one sitting in it.

You, of course, are causing it to do wheelies and spin-arounds from a concealed location, being careful not to hit anyone (remember the lawsuits).

Or build a little handheld programmer for those scrolling signs you see everywhere, plug it into the programming port on the sign, and upload the message of your choice.  How about those new billboard-sized displays?

Can you imagine one of those monsters showing reruns of I Love Lucy?  How about hijacking that big video display feed in Times Square during the New Years televised ball-dropping festivities and substituting a "Nuke the Whales!" message.

Fun is where you find it!

John W5EME's early interest in electromechanical devices prepared him well for a long career in electronics and the power generation and distribution industry.  He recently retired as a vice president of a high-tech manufacturing company.  After retirement, he now has a little time to enjoy his longtime interests in ham radio, robotics, and building microprocessor-based gadgets, with an occasional teaching or consulting gig.  Life is good.