Lets go back to POTs

Your wish is granted:

The mine owner and the labor union representative were watching a new steam shovel move huge amounts of dirt around the mine. The union rep declared "Such things are evil because they have taken away the jobs of 100 men with shovels". The mine owner asked "Why not 1000 men with teaspoons?" Are you sure you really want to raise the dead? Most often, the result is a zombie rather than whatever you were expecting.

That's a Strowger switch: The Ma Bell CO's were full of those back in the 1960's. I later used the rotary version in various radio repeater controllers. One was mounted on the panel near the middle of the rack, with the rotary dial on the right: My 1970 college senior project was a solid-state emulation of a rotary selector pulse dial decoder (Secode selector): used for calling mobile telephone customers.

They don't make 'em like that no more, for good reason.

First rule of machinery: If it moves, it breaks.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

I was just thinking of an app that would do just this, this last week ! I figured something existed. Thanks. Hadn't checked yet.

And don't forget Panel switching ! Similar but different...

Sounds of old phone systems....

There's an app for (almost) everything. Never mind the rotary retro dialer. I'm waiting for someone to write an ASL (American Sign Language) recognition app that will dial the phone from the camera. If I wasn't such a lousy programmist, I would probably scribble it myself.

One of the wonders of human psychology is how we manage to switch between the number pad layout on a telephone (123 on the top row) to the layout on a computah keyboard or calculator (789 on the top row) without brain damage. Even more remarkable is how we've accepted this ergonomic abomination without the usual complaining, blogging, and litigation.

I vaguely recall that there was at least one retrotech dialer that resembled a Motorola DynaTAC handset, but now all I find are dinosaur games and DynaTAC retro-clones:

I didn't have much experience with the switching equipment. The only switches I saw were Strowger, Crossbar, and 5ESS.

Yep, that was me in college. I was a teenage phone phreak.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Who said we switch. I mentally convert the numbers of a phone into the numbers of a computer keypad and touch dial the phone as if it were a computer keypad. Seems simple to me. There are only six digits to actually convert.

I hadn't thought of litigation. Thanks for the idea. Great reason to sue the phone company.

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  Rick C. 

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That would be me.

Very clever, but that's not what most people do. The majority look at the keys and read the labels. You can convince yourself how this works by trying to use a keyboard with the numbers covered. Be sure to also cover the zero and the decimal point. Extra credit for also covering the arithmetic symbols. On my HP calculator, the four arithmetic symbols are on the left in a vertical column. On my 101 keyboard, they are across the top, and make a right angle turn along the right column. If you have ever tried to dial a phone number using a calculator or 101 keyboard layout, you will probably notice a problem.

If you're still not a true believer, try randomly re-arranging the number pad keys on a 101 keyboard and remapping the key assignments using a key remapping program. I've done this and found that it takes me about 15 minutes of swearing to adjust to the new layout. After that, as long as I can look at the keys, I make about the same number of mistakes with a scrambled layout as with the original layout.

What happened is that I switched over to using the same method I use to find icons on my messy desktop: I don't look for an icon by a row or column linear search. I also don't type the first letter of the label. I tend to remember what area of the desktop the desired icon might be located, and limit my search to that area. That's also what I did with the scrambled number pad.

The remaining users are professional bookkeepers and people who do data entry. These are very accustomed the calculator and 101 keyboard layout that they can enter data without even looking at the keyboard. However, if someone makes even a minor change in the number pad keyboard layout, they fumble badly until they become accustomed to the change.

Way back in about 1960, I read an article in Bell Systems Technical Journal on the layout of the new Touch-Tone "signaling" system. Bell Labs was agonizing over the layout of the touch-tone keyboard. Different schemes were suggested and tested. The 123 across to top was selected allegedly by an opinion poll of the subjects involved in testing the keyboard layouts. Oddly, the 123 across layout was not used by calculators and bookkeeping machines of the day, which used a columnar layout.

In a heroic effort to maximize the damage, the ATM industry decided that more people were familiar with dialing a telephone than punching a calculator keyboard, and therefore adopted the touch-tone keypad layout for ATM keyboards:

Some net wisdom on the topic, all of which misses the real reason for the rather drastic change in layout.

So, why would Ma Bell (AT&T) in 1960 select a then rarely used keyboard layout and back it up with an ambiguous user study? I'll provide the answer in a day or two, after all the regulars have had time to provide the usual bad guesses.

Ah, that explains why your logic circuits appear to be damaged. Having to mentally remap every keyboard you encounter can certainly be difficult and eventually debilitating. I suggest you consult an ambulance chasing attorney for a projection on how much you might collect. Incidentally, if you can't document that you've had sufficient exposure to operating a numeric keypad, you might claim that you were exposed to second hand "radiation" from other users keyboards in the office.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Oh really ??!!!?? Early 70s, late 60s, so was I !!

That picture at the top of the phonetrips page is mine actually and that's me on the left. Except high school, not college.

What GREAT times those were ! At least we still have a couple good phone museums. The one in Seattle has most of the common switches working and talking to each other. Panel, #5 Xbar, #1 Xbar, Step and I think its' a #5 or #1 ESS.

My home town in Ohio had one of the first ESS systems, with a single dig it serial number. It replaced a very worn out Strowager exchange that barel y worked. They would haul in wrecked out equipment from smaller exchanges f or spare parts, to keep it limping along.

Sometimes you had to make a call three or four times to get a decent con nection, and it could take over a minute for the dialed number to ring beca use the old 20Hz ring generator was worn out. Backup power was an old farm tractor and a PTO driven generator. A local steel mill told Ohio bell that they either install a new exchange, or they would take their 10,000 block o f numbers private.

A few years later I was in the Army, and stationed in Alaska. I could ca ll my family in Ohio and get a better connection than I could get when call ing anywhere in town, when I left. The irony there was I had to use White A lice to make the calls, and it was older than I was. It was the first 'Over the Horizon' microwave telephone system, built during WW II for the Milita ry.

:

Certainly Benford's law holds true for base 2 numbers.

It would not hold true for phone numbers. Originally you only dialed excha nges, not area codes. Area codes were detected by a zero or one in the mid dle and there were no zeros or ones in the exchange at all. It was not unt il much later with the advent of digital switching equipment and the univer sal use of area codes that this rule could be relaxed. But to this day are a codes do not start with a one or zero.

With this original distribution of digits in the early system I'm pretty su re Benford's law was not in operation.

That's easy. The dial phone was 1-2-3-4-5-6-7-8-9-0. They thought this wa s important to preserve for some reason.

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  Rick C. 

  + Get 1,000 miles of free Supercharging 
  + Tesla referral code - https://ts.la/richard11209

If it were necessary to preserve the layout and order of the rotary telephone dial, the touch-tone pad would have been something like:

1 2 3 or 0 1 2 8 9 4 9 3 7 6 5 8 4 7 6 5

which form a circle or spiral of sequential digits. Methinks that the

2nd layout was one of the original suggestions in the 1960 user test. I don't recall exactly what was done with the 0 digit, but I vaguely recall something like these were proposed (with a circle drawn around the keypad to make it look something like a dial): 0 1 2 3 or 1 2 3 4 8 9 4 9 0 5 7 6 5 8 7 6

Ma Bell went through the same agony once again with the layout of the DynaTAC mobile phone handset, which originally used: I've been told that the original 2 column version was awkward to use.

1 2 3 4 5 6 7 8 9 0

I've only used the later 3 column TynaTAC version:

1 2 3 4 5 6 7 8 9 * 0 #

Here's a Nov 1960 test by Ma Bell in Bell System Tech Journal. Unfortunatly, it's not the article that compares various touch tone pad layouts.

Signaling Systems for Control of Telephone Switching Pg 1434 Various international rotary dials. Notice the zero and ten conflict in the dial from Sweden. The chart showing the various interoffice signaling systems was the basis of many blue boxes and telco hacks.

Digging for more goodies, I found: Tone Ringing and Push Button Calling, Mar 1958 Interesting, but nothing on testing various pad layouts. Photo of a modified Model 500 phone with touch tone keypad indicates that the layout decision was probably made prior to 1958. Also note that in Section 1.2, the purpose of the keypad was to provide signaling, not ringing, as in a 10 user party line. I guess(tm) this might have been before someone thought it might be useful for something else.

More (maybe):

Anyway, this is all rather disappointing. I expected more bad guesses from this group. I'll wait one more day before disclosing why AT&T selected a rather odd touch tone pad layout. Hint: There was no testing involved and you probably won't find it using Google or DuckDuckGo.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Oops and my apologies. Bad choice of words. I meant that at the time, I was also a teenage phone hacker, not that I was in one of your photos. Sorry for the confusion. Some random old photos of me:

In retrospect, my high skool and college daze were the best times of my life. My only real worry was getting drafted, which was a suitable inspiration for obtaining an education and getting tolerable grades.

I've never seen any of them. My involvement in phone hacking largely ended when I graduated college and became involved in businesses that could generate revenue, such as printing, smuggling, military adventures, 2way radio, lingerie manufacture, computahs, etc.

About 25 years ago, I managed to obtain guided (and guarded) tours of the local central office and some of the remote switching offices. Inside were rows and rows of Strowger and Crossbar switches, doing nothing. Of course, I asked, why were they still in the building. The answer was that they were "depreciating". Tax law required the telcos to depreciate their assets over an extremely long time (40 years?). So, it was financially beneficial to leave all the old equipment in place, long after they had been replaced, so as not to lose the deduction or possibly get hit with a recapture charge. Any of these building would have made an excellent working museum with all the old equipment still in place and ready to be demonstrated with the flick of a switch.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Sigh. I guess nobody is interested, so I'll just provide a short answer instead of my usual overly long and detailed rant on the topic.

In the 1950's, AT&T had a problem. It was a monopoly. In order to prevent being accused of abusing its monopoly status, it had to conform to certain business limitations. One of these was that AT&T should not be allowed to own every part of its business sector. It was agreed that AT&T should stay out of the growing computer business. AT&T suspected that if the proposed touchtone pad looked too much like a computer or calculator data entry device, someone might suggest that AT&T was selling poorly disguised computers. The easiest way to differentiate the telephone from a computer or calculator was to re-arrange the keypad layout. Since their 15 person population research showed that the layout had little effect on speed or accuracy, not using a calculator keyboard was an easy decision.

The original 1960 human factors study on touchtone pads: "Human factors engineering studies of the design and use of pushbutton telephone sets. The Bell System Technical Journal, 995-1012." The keypad layouts are shown on Pg 999.

Potentially interesting reports hidden behind pay walls:

"Expected locations of digits and letters on ten-button keysets" 1950

"Human factors engineering studies of the design and use of pushbutton telephone sets" July 1960:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Cool paper !

I don't know.... I liked the Bell TT pad myself. NOW, I use its layout to sometimes remember sequences of numbers by imagining that number on the TT pad.

The QWERTY keyboard numbers were, I am guessing, layed out the way they were after all the letters were layed out ?

Remember also that the TT pad also had the extra 1633 Hz column including Flash and Flash Overrride, etc. from the old AUTOVON netowork.

You probably know this but the # or "diamond' as Bell Tell called it was going to also be used for completing an overseas call back in the day, when otherwise you would have to wait for the call to be put through. This was because there were varying numbers of digits to different countries phone systems. I don't know if that feature was ever actually used though since I rarely dialed overseas by the usual means way back then. A friend and I would have the habit and I still do sometimes press # after dialing just for old times sake.

boB

The ability of the human mind to adapt to minor changes without exploding is IMNHO (in my never humble opinion) rather amazing. While I was considering the possibility of inscribing a long dissertation on the topic of keyboard layouts, I asked about 7 friends if they were confused by the changes in key arrangement between the phone, ATM, and computer keyboards. While some knew that they were different, nobody could remember the general arrangement of keys. Worst was the ATM key layout, which everyone (including me) wrongly assumed was the same as a calculator layout: The ability to adapt to different layouts is much like what happened when man learned to carry around a stick. We now "feel" things at the tip of the stick, not where we grasp the stick.

Yes. The numbers (and misc symbols) were located along the top row of keys:

You might be amused by the WWII Enigma cipher machine keyboard, which provided no numbers or symbols. To send a number, the Germans spelled out the numbers, much like is done on bank checks.

Yep. Those were highly prized at the time.

Not diamond, but rather "octothorpe": The best conspiracy theory is that Isaac Newton tended to scribble various abbreviations thus converting the "lb" into "#". In the

1950's, # and * were respectively "hash" and "splat". However, I've heard different usage in different parts of the country.

I don't recall ever seeing the # and * used for long distance signaling. Mostly, that was handled by a DTMF to MF (multi freq) tone converter when the call hit international circuits.

Marginally related drivel: [Q] How can one tell the difference between a number juggler and a word juggler. [A] Ask them both to produce a list of items. The number juggler will produce a vertical list, with one item per line. The word juggler will produced a long line and word wrapped list with items separated by commas. I sometimes use this to guess(tm) if someone asking a question on Usenet wants a numerical derivation full of equations, or a word salad description of the problem. Incidentally, the purpose of a tech writer is often to convert number juggler output into word juggler output.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558