I think the reason for this is pretty obvious. At the time -- for
many of the paper terminals, line feed simply rotated the platen, and
the print head stayed at the same column position. Carriage return
returned the print head to the first column without advancing the
paper (remember overstriking?). But there were also some terminals
that both advanced the paper and returned the print head (I'm hazy
about this, but I think the IBM Selectric was one...).
The Honeywell system in Murray Hill had a teletype driver that
attempted to paper over these differences. If it saw a linefeed on
some tty's they would issue the line feed and then space out to the
previous column location. If it saw a carriage return it would
backspace to the first column. It did recognize CR/LF and did
something more reasonable.
I do remember one guy who wrote his program to output LF/CR instead of
CR/LF. The teletype driver would do a LF and then space out to the
previous column and then do a carriage return. Pretty painful at 300
baud!
Doug might remember better than I but I suspect some terminal did the
combined CR/LF only, so that's why Unix adopted it. Certainly by the
time glass teletypes came along, making overstriking (and often
underlining) impossible, I don't think anybody objected.
Steve
----- Original Message -----
From: "Dave Horsfall" <dave(a)horsfall.org>
To:"The Eunuchs Hysterical Society" <tuhs(a)tuhs.org>
Cc:
Sent:Sun, 3 Sep 2017 12:54:02 +1000 (EST)
Subject:Re: [TUHS] Line Terminators in Text Files [Was: Re: Why Pascal
is Not My Favorite Programming Language - Unearthed!]
On Sat, 2 Sep 2017, Nemo wrote:
Hhhmmm... This begs the historical question: When did
LF replace
CR/LF
in UNIX?
Unix has always used NL as the terminator :-)
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will
suffer."