Today I learned that the reason we mostly encode [CARRIAGE RETURN + LINE FEED] and not [LINE FEED + CARRIAGE RETURN] has to do with teletype machines (these were typewriters hooked up to computers that supported input and output). Because CR is moving the print head about 8 inches right-to-left, and LF is scrolling the paper down ~1/4", LF took less time. If you sent CR/LF to certain models of teletype it could do the LF *during* the CR, saving a little time.


@darius I learned to type on a completely mechanical, human-powered typewriter; the return mechanism was a lever attached to the carriage and you had to push it the full length of a line. That blog post misunderstood the function of the bell. It would ring when you were about six characters away from the right margin, to warn you that you would need to push return at the end of the word. It did not ring again when return was pushed.

@zwol I learned to type on similar but I think I was so young I never understood the purpose of the bell!

@zwol @darius IIRC, at least on the massive blue IBM machines I learned on, the placement of the bell trigger was adjustable. Don't know if that was standard across machines.

@lrhodes @darius I don't think the typewriter I'm remembering had that feature. The margins themselves could be adjusted, though. I don't remember the model or brand name, only that it was light blue and had a late-1950s design aesthetic. It had been my mother's in college, and she let me practice on it when I was in elementary school in the 1980s.

@zwol @lrhodes @darius here's a picture of my Commodore typewriter where the bell mechanism is visible.

The right margin handle (grey ridged plastic thing) is adjustable, and moves with the carriage. It has a protrusion downwards which, as you type, first hits the bell trigger (visible in the gap, a wider metal bit) and then about 6 or 7 characters later hits the stop (visible in the cap, narrower sticking up metal bit) and at that point it doesn't let you type any more.

@zwol @darius Back in 1982, I was the only lad doing typing in school, because I though computers might become a Thing, and it would be a valuable skill*

The girls got the fancy machines, I had the 1950s Imperial. Wonderful machine.

*Now I can multi-lingual touch-type on a Mac, where you hold down a key and hit a number to get an accented character. One of the most useful things I learnt.

Sign in to participate in the conversation

Server run by the main developers of the project 🐘 It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!