Character width; was: these RTL or what?

Chuck Guzis cclist at sydex.com
Sat Oct 6 20:11:02 CDT 2007


On 6 Oct 2007 at 18:10, woodelf wrote:

> William Donzelli wrote:
> 
> > And being six bit machine in an eight bit world...
> > 
> SEVEN bit world. We can blame IBM for all our 8 bit PC ASCII stuff.
> Eight bits I think for EBDC was earlier. Having 4 bit sized TTL stuff
> does not make for nice octal digits. Ben.

The whole history of character respresntations in computers seems to  
have been pretty bleak to me.  Early decimal machines could use 00-99 
for characters, then binary machines adopted 6-bit characters--a 
*smaller* set.  At least 5-bit Baudot wasn't used much.

When customers started asking for lowercase characters on the CDC 6-
bit machines, IIRC, there were seveal approaches suggested.  One was 
to pack 7.5 characters into a 60 bit word.  Someone coined the term 
"snaque" for this unit (bigger than a byte, get it?).  I'm not aware 
that the system was ever widely deployed, thankfully.  Instead, 
uppercase characters were represented with their usual 6-bit codes, 
while lower-case was denoted with a 00 "escape" character.  So, 
"HELLO" woud be represented in octal as 10 05 14 14 17 and "Hello" 
would be represented as "10 00 05 00 14 00 14 00 17".  (Hope I got 
that right!).

6 bits was miserably crowded when numbers and punctuation were added. 
 In particular, I recall that double-quote and "not equals" shared 
the same code--what came out on your listing depended on what type 
train was installed in the printer.

In retrospect, a 12-bit character would have made a huge amount of 
sense--12 rows on a punch card, so nn need for translation hardware 
to somehow turn legal and illegal punch combinations into characters. 

Lots of room to grow--perhaps not enough for the ideographic 
alphabets, such as Kanji, but enough for most writing systems.  Octal 
or hexadecimal accommodated equally well.

In the Sepember IEEE Computer magazine, Neville Holmes wrote a squib 
on "The Profession as a Culture Killer", with some note of the new 
ICANN rules allowing non-Latin characters to be part of domain names. 
 I don't agree with everything he wrote, but he had some points.

Cheers,
Chuck








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