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Re: Binary formats

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"Helmut_Meukel" <Helmut_Meukel@bn-hof.invalid> wrote in message 
news:jljls2$q5e$1@dont-email.me...
> DonH stellte die Frage:
>> "Helmut_Meukel" <Helmut_Meukel@bn-hof.invalid> wrote in message
>> news:jl1igf$f7n$1@dont-email.me...
>>> Am 29.03.2012 erklärte R.Wieser:
>>>> DonH wrote:
>>>>>     For example, in back of book "Computer Programming
>>>>> in Basic" (Carter and Huzan), there is an ASCII 64-character
>>>>> set, in which binary is a 7-digit code; yet elsewhere can be
>>>>> 8-digit, etc.
>>>>
>>>> I'm afraid you misunderstood that.  ASCII is the standard in which the
>>>> characters beteen codes 32 and 126 are defined (human readable), as 
>>>> well
>>>> as
>>>> most of the characters below code 32 and ofcourse 127 (for special
>>>> purposes,
>>>> like Carriage-return=13 and Linefeed=10.  127 *was* used as DEL) . 
>>>> AFAIK
>>>> there is *no* 64-character ASCII standarized definition.
>>>
>>> Not ASCII, but the originally 5-bit Baudot code:
>>> <http://en.wikipedia.org/wiki/Baudot_code>
>>> used for teleprinters.
>>>
>>> BTW, the 7-bit ASCII was designed that it /could/ be used as a 6-bit
>>> (=64 chars) code (without lowercase characters), but I've never
>>> encountered such an use.
>>>
>>>>
>>>> As for ASCII in 7- or in 8-bit ?  That is a bit of cheating (pun not
>>>> intended):  The smallest unit in which current PCs store information is 
>>>> a
>>>> "byte" (or more correctly: an octet) consisting outof 8 bits.  When an
>>>> ASCII
>>>> character is stored into such a byte the highest/leftmost bit is simply
>>>> always Zero.
>>>
>>> But that's only true for the internal representation of the code.
>>> If transferred to external devices like printers via a RS232 line
>>> the eighth bit could be used as a parity bit.
>>> You had to select the parity on both devices either off or on.
>>> If no parity was selected, then usually the parity bit was set to "0",
>>> but I used devices which allowed to set it to "1".
>>> If parity was used you had to select "odd" or "even" parity and the
>>> parity bit was then set according to match the other 7 bits.
>>> e.g. "A" is Hex 41 = Dec 65 = Oct 101 = Bin 01000001
>>> With parity set to "odd", the binary value 11000001 was sent to the
>>> printer.
>>>
>>>> If-and-when you see a character which has the highest bit set (meaning:
>>>> its
>>>> code is in the range 128 ... 255) its is *not* ASCII.
>>>>
>>>> Although, IBM (the company) did create a set of special characters, 
>>>> some
>>>> of
>>>> which not even letters but graphics (among others to draw boxes with), 
>>>> and
>>>> did give it the name "extended ASCII".  That name somehow stuck.   But 
>>>> its
>>>> just not standarized.
>>>
>>> Even IBM superseded it later on with "Code Pages", the originally
>>> "extended ASCII" became Code Page 437.
>>>
>>> Helmut.
>>>
>>>
>>
>> # I assume that a "parity bit" is a "check sum" at binary level.
>>    However, there seems no such digit in the 7-bit code of the "64 
>> character
>> set", as the first 32 binary codes start with 0, while the second start 
>> with
>> 1, giving a code range of 0100000 (space), to 1011111 (leftwards arrow).
>
> I wrote about the 7 bit *ASCII* code, which is stored within 8 bits.
> Even to external devices like printers, usually 8 data bits were
> transmitted. So you had an eighth bit to use as parity bit.
>
> I don't quite understand what you are talking about when you refer to a
> "64 character set", because you would always need the first 32
> - unprintable - characters of the ASCII code. ´Some of those control
> codes are essential for structuring the data and to tell the external
> device how to react to the transferred data.
> e.g. "Backspace", CR, LF, FF (Form Feed), Bell, STX (Start of TeXt),
> ETX (End of TeXt), EOT (End of Transmission), RS (Record Separator),
> FS (Field Separator), GS (Group Separator), ...
>
> BTW, ASCII stands for American Standard Code for Information Interchange.
>
> Helmut.
>
>

# My reference to a "64 Character Set" is as displayed as Appendix C in book 
quoted above which was, incidentally, first published in 1981.
   This book, "Computer Programming in Basic" is an excellent book in many 
ways, and is in the Teach Yourself Books series, published by Hodder and 
Stoughton. (163 pgs)
   Authors: L.R.Carter, and E.Huzan.  (ISBN: 0-340-32434-1)
   There have been many books on Basic and computers since, but this is one 
I often return to. 

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Binary formats "DonH" <donlhumphries@bigpond.com> - 2012-03-28 07:18 +1100
  Re: Binary formats "R.Wieser" <address@not.available> - 2012-03-27 23:42 +0200
    Re: Binary formats "DonH" <donlhumphries@bigpond.com> - 2012-03-29 06:15 +1100
      Re: Binary formats "R.Wieser" <address@not.available> - 2012-03-29 01:17 +0200
        Re: Binary formats Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-03-29 13:53 +0200
          Re: Binary formats "R.Wieser" <address@not.available> - 2012-03-29 14:30 +0200
            Re: Binary formats Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-03-29 21:01 +0200
              Re: Binary formats Hector Alfaro <alfaropas@ceropublicidad.com> - 2012-04-01 15:25 -0430
          Re: Binary formats "DonH" <donlhumphries@bigpond.com> - 2012-04-04 06:09 +1000
            Re: Binary formats Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-04-05 10:41 +0200
              Re: Binary formats "DonH" <donlhumphries@bigpond.com> - 2012-04-06 05:54 +1000
                Re: Binary formats ralph <nt_consulting64@yahoo.net> - 2012-04-05 21:21 -0500
        Re: Binary formats "news@rtrussell.co.uk" <news@rtrussell.co.uk> - 2012-03-29 01:32 -0700
  Re: Binary formats Helmut_Meukel <Helmut_Meukel@bn-hof.invalid> - 2012-03-27 23:34 +0200

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