CYBER word length

Ken Latham latham at bsdpkh.UUCP
Wed Nov 12 18:37:29 AEST 1986


> 
> In article <612 at astroatc.UUCP>, philm at 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



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