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From: latham@bsdpkh.UUCP (Ken Latham)
Newsgroups: comp.unix.wizards
Subject: Re: Re: CYBER word length
Message-ID: <254@bsdpkh.UUCP>
Date: Wed, 12-Nov-86 03:37:29 EST
Article-I.D.: bsdpkh.254
Posted: Wed Nov 12 03:37:29 1986
Date-Received: Wed, 12-Nov-86 22:02:13 EST
References: <4169@amdahl.UUCP>
Organization: AT&T-IS (SDSS), Orlando Fl.
Lines: 30

> 
> In article <612@astroatc.UUCP>, philm@astroatc.UUCP (Phil Mason) writes:
>>                       CDC thought that nobody would ever use more than 64
>> different symbols for I/O so they made their "byte" six bits long.  Packing
>> ten of them in a word is convenient, to say the least.
> 
> And then they discovered that people would use more than 64 symbols, and
> had to come up with an escape kluge to get additional symbols.  So now
> CDC Display Codes can be either 6-bits or 12-bits in length.
> 

	No!  not really.

	CDC  uses prefix characters for additional display codes in
	much the same way that ANSI uses ^[ to prefix an incoming
	(outgoing) control string.

	You could no more say that ^[[2J  (ANSI clear screen) is
	32-bits long, than you can call CDC codes 12 bits long.

	CDC sends one of several prefix codes ( micro, super, sub, shift ... )
	to apply to the following character ( sometimes combined they
	affect more than one character )

	This is definitely NOT a KLUDGE !!!  It is a valid way of extending
	display codes.  It is far better than extending the bit length
	to include one number for each display alternative you have.


					Ken Latham