As you all know the ASCII chart needed to be extended from 127 encoding to 256, I can't really see why. Some google expert on Coursera said "We needed that because of the foreign languages". I still Can't understand what that has to do with the ASCII Chart.

enter image description here

Can anyone explain the full story?

  • 20
    $\begingroup$ Your username contains a symbol which isn’t contained in your chart. $\endgroup$ Mar 21, 2020 at 9:16
  • 1
    $\begingroup$ The source of the image you posted also contains an image for the ASCII characters 128 to 255. It should be pretty clear that at least the first few of those are used in other languages and they don't appear in the first 127 ASCII characters. How else would you represent those characters in text? It should also be pretty clear that both of these entirely ignore languages not using some variant of the Latin alphabet, but this problem was later solved with Unicode. $\endgroup$ Mar 21, 2020 at 16:39
  • 3
    $\begingroup$ @Dukeling there are no ASCII characters 128 to 255. $\endgroup$
    – hobbs
    Mar 21, 2020 at 17:56
  • 2
    $\begingroup$ This looks like a question that would fit better on retrocomputing.stackexchange.com. We just had a question there about the history of Unicode- Could we have avoided the whole UTF-16 fiasco? even 16-bit codepoints weren't enough for all the world's languages. $\endgroup$ Mar 21, 2020 at 20:13

3 Answers 3


ASCII has 128 characters. Many countries had similar encodings for 128 characters. That is all history. Nobody uses ASCII anymore. There was a phase with lots of different encodings for more than 128 characters, some with 256 (Mac Roman and Windows 1152 were quite popular) and some like the Chinese GB with thousands of characters.

Nowadays people mostly use Unicode, with a bit over a million code points, which can be further combined to produce more characters. There are plenty of unused code points which can be assigned values in the future, and that happens all the time.

Please note that for most people English is a foreign language. And it would be “naïve” to think that ASCII let’s you write all English text.

  • 5
    $\begingroup$ +1 for naïve - but it should be noted that sooner or later all unicode codepoints will be eaten by emojis as everyone thinks that to express a vaguely understandable idea requires a new glyph instead of a simple sequence of ~26 standard letters sigh $\endgroup$ Mar 21, 2020 at 19:12
  • 2
    $\begingroup$ @HagenvonEitzen: fortunately(?) emojis can be composed as a sequence of two codepoints that combine to form one grapheme. Let’s Stop Ascribing Meaning to Code Points gives the example of the US-flag emoji being two codepoints. (related - Could we have avoided the whole UTF-16 fiasco? on retrocomputing is still in hot network questions and has some more discussion, including that link in a comment.) $\endgroup$ Mar 21, 2020 at 20:38
  • $\begingroup$ @PeterCordes There are the emojis for "family" where you have one or two code points for the parents by gender, additional code points for skin color, I think for the hair color as well, and then the same for their kids - a dozen code points for an emoji is quite possible. $\endgroup$
    – gnasher729
    Mar 21, 2020 at 21:47
  • $\begingroup$ @gnasher729: Do you really mean a sequence of a dozen codepoints for one version of a single emoji? Rather than a dozen different variations of a single or pair of codepoints using up lots of coding space? I think you meant the former but that sounds pretty nuts so I wanted to double check. $\endgroup$ Mar 21, 2020 at 23:22

There are a few other good reasons to expand from 7-bit ASCII, but since you ask specifically about foreign languages, I want to tell you about that angle.

English has words with diacritical marks, usually loan words like naïve or café. They are rare, and usually you'll get into no trouble for omitting the diacritics. Occasionally one might stumble into a word that means something else when you omit the diacritical marks, such as exposé vs expose, but those cases are rare and usually the meaning can be inferred from the context without much difficulty.

The same is not true for most languages written on the Latin alphabet, though. Romance languages like Italian, French, Spanish and Romanian use diacritics much more than English does, and omitting the diacritics as 7-bit ASCII would impose would make text harder to read. The same is true for Germanic languages other than English, as many of those make heavy use of umlauts and special letters like the å found in Swedish. My native Finnish, too, considers ä, ö and å to be separate characters distinct from a and o, and telling them apart from each other is necessary to correctly parse words without needing to infer from context.

Therefore, when computing picked up pace among users who do not use English as their native language, it was essentially inevitable that the character sets should be expanded. The alternative would have been massive orthographic reforms in some of the most spoken languages in the world to make them conform to the limitations of the increasingly vital computers. That would not have worked out – although semi-official conventions did occasionally spring up (eg. replacing ö with oe). So in order to not get in the way, 8-bit Extended ASCII encodings usually lend support to these special characters, relieving at least some of the non-English languages.

Fast-forwarding to today, Unicode has support for a vast array of characters that extend the support well beyond Latin-based alphabets as well. This means almost everyone can type their native languages without the computer's charset limitations needing to get in the way.

  • 1
    $\begingroup$ One of the ways was to to use [ | ] and { \ } for ÅÄÖ and åäö on Swedish printers. $\endgroup$
    – ghellquist
    Mar 21, 2020 at 18:56
  • 3
    $\begingroup$ Adapt language to computer-imposed limitations? LOL! R u kidding? $\endgroup$ Mar 21, 2020 at 19:15
  • 2
    $\begingroup$ @HagenvonEitzen We (Malaysia & Indonesia) adapted our language to typewriter-imposed limitations. Both versions of formal Malay - Malaysian & Indonesian - used to be written with modified Arabic script. But there were no typewriters around that supported it (there were typesetting systems that did but they were really complicated and mostly manually laid-out). So we switched to "Rumi" (Roman) letters which is essentially the English alphabet (Dutch for Indonesian) $\endgroup$
    – slebetman
    Mar 21, 2020 at 19:48
  • $\begingroup$ and will make text harder to read - I think you're still talking about omitting them making text harder to read. That context was a while ago and bears repeating, otherwise (especially when skimming) it sounds like you might be saying that the presence of diacritics makes those languages harder to read. $\endgroup$ Mar 21, 2020 at 20:42
  • $\begingroup$ Interesting point, I hadn't ever thought about "exposé" being a different spelling from "expose" - English has lots of homonyms like "lead" (the chemical element), "lead" (pronounced leed, as in leadership), and "lead" (past tense of "to lead"). So yes, native English speakers are used to distinguishing homonyms in written text based on context even when they don't have diacritics, and wouldn't tend to think about the diacritic when it's not there. $\endgroup$ Mar 21, 2020 at 20:46

The question of how foreign languages justifies expanding the encoding in actual usage is well explained by earlier answers. The question of why foreign languages would affect the American Standard Code for Information Interchange is subtly different.

As you all know the ASCII chart needed to be extended from 127 encoding to 256

No. The original American Standard Code for Information Interchange (ASCII) has never been extended to 8-bit. It remains to this day a 7-bit encoding standard. The latest revision to the ASCII standard was in 2017, with (ANSI) INCITS 4-1986[R2017].

Due to the same needs for exchanging computer information, non-English speaking countries have to develop their own standard codes. The countries using Latin scripts were already using ASCII in their computers and existing documents. When the 8-bit word architecture became popular, they developed their own standard codes based on the 7-bit ASCII, using the additional bit-space for additional symbols they need. By habit, these standards are sometimes called "extended ASCII" standards. But they are actually new standards, and to this day remain distinct from ASCII. They are standardized as ECMA-94, ECMA-113, ECMA-114, ECMA-118, ECMA-121, ECMA-128, and ECMA-144, as well as the ISO/IEC 8859 series.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.