Re: Meaning behind Control-G

[Paul Eggert <eggert@cs.ucla.edu>]

On 6/1/20 6:44 AM, Stefan Monnier wrote:
> FWIW, the link between C-g and "BEL" is pretty clear: it must be
> [G]raham [Bel]l

Hah! As long as we're guessing, why not [G]ordon [Bel]l? His early work predates
ASCII and Wikipedia says he designed the first UART (this was for the PDP-1) so
he was very much in the thick of things when Control-G was invented. I'll cc him
in this email to see whether he knows whether Control-G and BEL are related
because of him.

It's unlikely, though. I looked it up, and BEL goes back to the Western Union
code (sometimes called the Baudot-Murray code, ITA2, or CCITT#2) invented in
1901. It was a 5-bit code with an escape, and BEL was an escaped J. The New
Zealand inventor Donald Murray invented BEL to ring the mechanical bells in his
telegraphic typewriters. (Murray eventually became rich from his teleprinter
patents and died a wealthy philosopher in Switzerland.)

When ASCII was developed in the early 1960s, BEL was one of the standardized
characters for compatibility with ITA2. The developers of ASCII looked at all
the control characters to be standardized, and attempted to maximize the Hamming
distance between the bit patterns of pairs of control characters where confusion
was likely to cause the most damage. (This little tidbit of information comes
from page 245 of Charles E Mackenzie's 1980 book "Coded Character Sets, History
and Development".)

The best person to ask exactly why C-g was assigned to BEL would be Bob Bemer,
co-developer of COBOL and sometimes called the "Father of ASCII" for his lead
role in ASCII standardization. Unfortunately for us he passed away in 2004.

That being said, Western Union and Bell were bitter commercial competitors (see
the Telephone Cases of the 1870s and 1880s), and I very much doubt that Western
Union would name one of its character codes after Alexander Graham Bell.