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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