Talk:Telephone keypad

Why did old phones have no Q and no Z on the keypad? 69.143.164.131 14:59, 3 March 2007 (UTC) Landon Greive

I'm wondering the same thing. 156.34.214.201 (talk) 02:14, 23 November 2007 (UTC)

The 26 letters of the standard English alphabet are not evenly divisible by 10, the number of digits on a dial or keypad. The closest number which results in an even distribution is 24 which is 3 x 8. So you leave the "1" without any letters associated, "0" (the numeral) is reserved for "operator"; the 8 remaining digits each get 3 letters. The 2 missing letters, "Q" and "Z" are both low frequency in English; their lack did not seriously limit use of words for exchanges. This is my guess. 69.29.207.109 (talk) 02:09, 6 April 2010 (UTC)

Wow, that's an incredibly intelligent and informative answer, thanks. 156.34.214.201 (talk) 22:46, 14 July 2011 (UTC)

The "3 x 8" 24-letter allocation on digits 2 through 9 mentioned above was known as the Blauvelt dial when it was adopted in the early part of the 20th century. In the U.S.A. many dials did add the letter "Z" to the zero position in later years, e.g. it was commonly found on the dials of Western Electric 302 sets through the 1930's & 1940's. However, when the 500-set (and its equivalents from other manufacturers) started to replace these from the 1950's onward, the "Z" was dropped again.

There are at least a couple of stories as to why "Z" was added. One is that it was to catch users being told to "Dial zero for operator" actually trying to dial out the word Z-E-R-O. Placing "Z" on the zero position would thus send the call to the operator on the first digit anyway, the other digits being ignored. The second, and rather more plausible, story related to Zenith numbers. These were the forerunners to today's 800 numbers, in that they were free to the caller, with the company being called picking up the bill. But they could not be dialed directly, you had to call the operator and ask for "Zenith 1234" or whatever the number happened to be. So with "Z" on the zero position, anyone who attempted to dial a Zenith number as if it were a regular local exchange would dial zero as the first digit and be connected to the operator immediately.

In the U.K., the Blauvelt dial had a small change applied before it was adopted, with the letter "O" being moved to the zero position, leaving just "MN" on 6. The letter "Q" was then added to the zero position at the end of the 1950's. It wasn't needed for any names within the U.K., but direct dialing to Paris, France was being anticipated (it actually commenced in 1963), and French dials already had "Q" on the zero, since some of the Paris exchanges had "Q" in the names (e.g. ROQuette). So "Q" was added to British dials for direct-dialed calls to Paris, and it was fortunate that all of the other letters were already the same between French & British dials.

One of the contributing reasons to letters eventually being phased out was to accommodate international dialing as it started to become more common in the 1960's. Even between the English-speaking countries of the U.K. and the U.S.A. there would obviously have been a problem with the different position of the letter "O" when trying to dial a number such as ACOrn 1234. The dials in some other foreign countries used completely different arrangements. 87.113.35.221 (talk) 13:10, 14 October 2012 (UTC)

Calculator and Keypad reversed - need a reason why.

At howstuffworks they propose three theories. (1) To slow data entry people down so the touchtones don't run together causing a misdial, (2) The result of a study by Bell labs, and (3) To follow the rotary phone numbers left to right similar to the way the western world reads.

I personally think there is a simpler answer. During rotary phone days, the alphabet followed left to right in sequence. If the digits followed the calculator sequence, the alphabet would be upside down by the way the western world reads top to bottom. By placing the numbers the way they did, the letters are more easily found.

Said another way, theory #3 at howstuffworks is almost the same as I have stated, but the ALPHABET drove the sequence, not the numbers. —Preceding unsigned comment added by 71.240.129.53 (talk) 01:19, 23 December 2007 (UTC)

Why should they be the same?

You should check the Bell labs research paper, the usability studies they conducted are quite impressive and they broke down the pros and cons of all of the nearly 20 layouts they considered. — Preceding unsigned comment added by 81.197.47.223 (talk) 00:04, 13 January 2014 (UTC)

The alphbet theory makes the most sense.

Always was curious. But ATMs use the phone numbering system as well... Anyone know why ATMs used the Phone layout vs computer layout? —Preceding unsigned comment added by Strickjh2005 (talk • contribs) 15:07, 8 February 2008 (UTC)

Star(*) & Pound(#)

What was the original purpose of putting the star & pound keys on the key pad. Calling cards & voicemail weren't invented yet.. —Preceding unsigned comment added by Dig1234 (talk • contribs) 01:54, 28 February 2008 (UTC)

Special features, maybe (i.e. *76)? ~ 69.91.165.87 (talk) 21:18, 3 April 2009 (UTC)

I believe they came out before features such as those existed. Remember, Operators still used manual switch boards back in the 60's and 70's, so most likely, these keys were used to send a signal to the operator for reason. HanokOdbrook (talk) 01:49, 9 August 2011 (UTC)

They came out before services such as call-forwarding, call-waiting etc. which use "star" code came into use, but these sort of services were certainly being anticipated at the time the DTMF keypad was being developed, as were various computer controls via DTMF tone sequences, so these two additional symbols were included to allow for these uses, plus whatever extra control features might be dreamed up for them in the future. Some of the original prototypes used a diamond-shaped symbol in the position to the right of zero, before the current "#" was eventually decided upon (which is why in telephone circles the "#" key has yet another name - "Diamond").

Remember though that the original DTMF keypads fitted to telephones for general use by the public were only 10-button types with the normal digits (the Western Electric 1500 and equivalents). It wasn't until the later 1960's that the 12-button keypads with "*" and "#" (Western Electric 2500 sets et al) became standard for all new phones.

Also, remember that the DTMF standard includes a fourth column, to the right, with the general designation of the keys being A, B, C, and D. These were also anticipated for use as control signals for networks and computers, probably the most well-known usage being that adopted by telephones for the Autovon military network, where phones had an extra column of red keys which were used to set the priority for urgent calls (in descending order of priority from the top button downward: FO - Flash Override, F - Flash, I - Immediate, and P - Priority). 87.113.35.221 (talk) 13:34, 14 October 2012 (UTC)

anyone for including "Mesh" in the list of things that the octothorpe gets called? also "Tic tac toe board" —Preceding unsigned comment added by 168.251.194.18 (talk) 22:29, 5 November 2009 (UTC)

Security

Often banks tell you not to use a cell phone or cordless phone when doing telebanking, makes sense. But, they also say to only use a telephone which has the number buttons on the base as opposed to buttons on the handset. Perhaps this could be addressed in the article. 156.34.232.171 (talk) 18:00, 13 March 2008 (UTC)

document accuracy.

just to justifythe acurate nessof this articles. i changed the area code in the example for aylesbury, which was 01293 to the actual 01296, which was probably a typo. as a local, i feel the duty. —Preceding unsigned comment added by Johnny45irish (talk • contribs) 13:51, 6 July 2010 (UTC)

0293 was actually 0CY3 for Crawley. 87.113.35.221 (talk) 13:19, 14 October 2012 (UTC)

And speaking of accuracy I've made a couple of changes in the "Letter mapping" section, since the example given of WHItehall 1212 being different when dialed on a French telephone versus a British telephone wasn't actually a valid example (French & British dials used the same letter allocations, with the exception of "Q" on French dials, and even then the "Q" was added to British dials later for direct-dialling to Paris). So I've changed the basis of comparison to British versus Danish dials and used London's VICtoria exchange, since the "C" was on the "1" position on Danish dials, as compared with "2" on British dials. 87.113.35.221 (talk) 13:45, 14 October 2012 (UTC)

Suggestion - merge John Karlin bio article to this article

I've put {{merge to}} on John Karlin suggesting the biographical article be merged into this one. My thinking is that Karlin is, as currently represented, only notable for the telephone keypad development (referring to WP:1E as a policy backing). I am not strongly opposed to Karlin's biographical article remaining as a separate article; I thought it would be useful to consider. A consequence would be a substantial reduction of the biographical content. Consider also that Karlin's biography is based on a single citation (at present). Thanks for considering this. There are arguments which could be made that Karlin should not be associated with this article so intimately as a merge would imply, but rather with some elements of human behavior and perception; I've not thought through that line in any depth, though. --User:Ceyockey (talk to me) 00:26, 16 April 2014 (UTC)

Agree, article is small and name is the same phonetically to John Karlen a much more prominent article.TacfuJecan (talk) 21:48, 26 March 2016 (UTC)

newbie question

On the ITU standard keypad in the photo at the top of this article, there's a double loop on the key for the "1". I have that on my cell phone virtual keypad too. What on earth is that thing? I said it was a newbie question. 100.15.138.239 (talk) 18:17, 15 September 2016 (UTC)

Some Google searches seem to indicate it's a symbol for voicemail. I didn't really find a good source, but it appears to be based on a reel-to-reel tape deck, or on the reels inside a cassette tape. Jayscore (talk) 19:27, 6 December 2019 (UTC)