Re: ASCII

["..." yesss@xxxxxxxx]

≪ Replay to "--a" about 8 bit ASCII: Or I misunderstand
what you say, or something is wrong on that. Using 7-bit
you can produce only 128 chars, not 256. In ancient
computers the seventh bit was used only for parity check
in text transmissions. Today also, in fact, you can set
the serial port to be "8 bit no parity" or "7 bit + parity"
(odd or even). Ciao ≫ --Adriano Ortile 

Hi, Adriano. I glibly got myself in over my head on that one.
Fortunately, another subscriber privately pointed out more
or less the same thing you did, so I have an explanation--his.

I first replied to him that I just muddle along, trusting
my desert-island C language reference, Nabajyoti Barkakati's
"The Waite Group's Turbo C Bible" (Sams, 1989).
Introducing the ctype.h macros (p251), Barkakati writes:

		The ASCII character set relies on a 7-bit code
		to represent all letters, numbers, punctuation
		symbols, and some special (unprintable) control
		characters. [ ... ] Beyond the basic 128, the IBM PC
		also supports character codes from 128 through 255
		that a single unsigned C character variable can
		represent.

I believe my correspondent would rather not have his
name dragged into this, so I'll quote his response
to that anonymously:

≪ The basic 128 character ASCII set uses all the options
that seven bits provide. The IBM PC, with an extra bit
available in each byte, is able to use an additional 128
"extended" characters by using an unsigned C CHAR variable,
which is a full 8-bit byte. The additional bit adds an
extra 128 available positions, which are not part of
the ASCII standard and are used by different standards
in different ways. ≫

All *I* know is what I read, and I'm most grateful to
"Anonymous" for his generosity and expertise. ... Ciao. 	--a

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