7-bit ASCII, how many characters?
A technical question: Exactly what characters make up 7-bit ascii? I presume it is 128 (2 to the 7th power). So logically any character I can generate by typing Alt+0000 thro' Alt+0127 (in MS Windows) is kosher in a 7-bit ASCII text. Specifically I want to know if I can us "|" (the character made by hitting Shift+backslash on a standard US keyboard, or Alt+0124). Generally, are the following (Alt+0000 thro' Alt+0127) always okay? ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _ ` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~ --------------------------- Dennis McCarthy nihil_obstat@mindspring.com
On Fri, Nov 26, 2004 at 01:09:53PM -0500, Dennis McCarthy wrote:
A technical question:
Exactly what characters make up 7-bit ascii? I presume it is 128 (2 to the 7th power). So logically any character I can generate by typing Alt+0000 thro' Alt+0127 (in MS Windows) is kosher in a 7-bit ASCII text.
Specifically I want to know if I can us "|" (the character made by hitting Shift+backslash on a standard US keyboard, or Alt+0124).
Generally, are the following (Alt+0000 thro' Alt+0127) always okay? ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _ ` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~
Depends what you mean by "okay". Anything in the range 32 (space) through 126 (tilde) is definitely OK, and common. Your specific character, 124, is commonly used by people who want to create a box-like layout. Below 32, chars 10 and 13 (LF and CR) are definitely necessary at the end of every line, but character 9 (Tab) is specifically discouraged, because of the undefined effect it may have on different viewing or editing programs. Other characters below space (32) . . . well, I imagine someone could come up with a useful reason to use one or more of them, in some special situation, but I can't think of one right now. Ditto 127, whose only reason for existence is to delete another character. jim
On Fri, 26 Nov 2004 13:09:53 -0500 (GMT-05:00), Dennis McCarthy <nihil_obstat@mindspring.com> wrote: | | A technical question: | | Exactly what characters make up 7-bit ascii? I presume it is 128 (2 to the 7th power). So logically any character I can generate by typing Alt+0000 thro' Alt+0127 (in MS Windows) is kosher in a 7-bit ASCII text. | | Specifically I want to know if I can us "|" (the character made by hitting Shift+backslash on a standard US keyboard, or Alt+0124). | | Generally, are the following (Alt+0000 thro' Alt+0127) always okay? | ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _ ` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~ Not everyone used Windoze there are some 500 8 bit character sets in use, but many are obsolete/obsolescent. See http://www.asciitable.com/ Decimal 0 to 31 are control characters and unusable in text. They may be many other things besides control characters. Decimal 32 is space. Decimal 33 to 126 are usable in 7 bit ASCII text as listed in the URL Decimal 127 is unusable. Decimal 128 and above may be absolutely anything, to use these one must state which of the 500 character sets you are using. One persons standard sends the next person insane :-( -- Dave F
If you have a standard US keyboard, then any of the keys you can hit (excluding the function keys), with or without the shift key, are ASCII. (ASCII also includes "control" characters, 0000 thru 0031, which you won't see, and won't want to enter anyway.) The "|" (vertical bar or pipe) is certainly legit ASCII. Steve Quoting Dennis McCarthy <nihil_obstat@mindspring.com>:
A technical question:
Exactly what characters make up 7-bit ascii? I presume it is 128 (2 to the 7th power). So logically any character I can generate by typing Alt+0000 thro' Alt+0127 (in MS Windows) is kosher in a 7-bit ASCII text.
Specifically I want to know if I can us "|" (the character made by hitting Shift+backslash on a standard US keyboard, or Alt+0124).
Generally, are the following (Alt+0000 thro' Alt+0127) always okay? ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _ ` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~
--------------------------- Dennis McCarthy nihil_obstat@mindspring.com
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On Fri, 26 Nov 2004, Dennis McCarthy wrote:
Exactly what characters make up 7-bit ascii?
Generally, are the following (Alt+0000 thro' Alt+0127) always okay?
One thing I might add to this discussion is a matter of semantics. The character _`_ does belong to ascii (96-decimal, 60-hex) However it is a spacing grave accent mark, and not an opening single quote, which you may sometimes see it used for in text files. A while ago, I had the address of a web page which explained in detail why ASCII-96 should not be used as an opening single quote, but I can't find it now. Andrew
Andrew Sly <sly@victoria.tc.ca> writes:
A while ago, I had the address of a web page which explained in detail why ASCII-96 should not be used as an opening single quote, but I can't find it now.
Search for "Markus" and "Kuhn" and "quote": http://www.cl.cam.ac.uk/~mgk25/ucs/quotes.html -- http://www.gnu.franken.de/ke/ | ,__o | _-\_<, | (*)/'(*) Key fingerprint = F138 B28F B7ED E0AC 1AB4 AA7F C90A 35C3 E9D0 5D1C
On Sat, 27 Nov 2004, Andrew Sly wrote:
On Fri, 26 Nov 2004, Dennis McCarthy wrote:
Exactly what characters make up 7-bit ascii?
Generally, are the following (Alt+0000 thro' Alt+0127) always okay?
One thing I might add to this discussion is a matter of semantics. The character _`_ does belong to ascii (96-decimal, 60-hex) However it is a spacing grave accent mark, and not an opening single quote, which you may sometimes see it used for in text files.
A while ago, I had the address of a web page which explained in detail why ASCII-96 should not be used as an opening single quote, but I can't find it now.
Since French doesn't really USE the ` with the spacing, other than in cases where we usually would use _`_ or " ' " etc, it is really somewhat of a moot point. In addition, if this really had been intended to be a French accent grave, why is the "_" between it and the " ^ " which could be the French accent cironflex. . .not to mention the lack of an accent aigue, etc. . . . 87 57 W 88 58 X 89 59 Y 90 5A Z 91 5B [ 92 5C \ 93 5D ] 94 5E ^ <<< 95 5F _ 96 60 ` <<< 97 61 a 98 62 b 99 63 c Michael
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