>the lever would do LF, and pushing on it further would do CR (tensioning the carriage spring).
In any case, carriage return is just as important function of the lever as line feed:
- you can also directly do line feed by turning the roller
- line feed, by itself, doesn't need a large lever
- carriage return, by itself, doesn't need a large lever either - you can simply push the carriage
- however, having a large lever is an ergonomic feature which allows you to:
1) return the carriage without moving your hands too far from the keyboard
2) do CRLF in one motion without it feeling like two things
3) If needs be, do a line feed by itself, since the force required for that is much smaller compared to the one to move the carriage (lever advantage!).
The long lever makes it so that line feed happens before carriage return. If the lever were short, you'd be able to move the carriage until it stops, and only then would the paper move up.
So I wondered why the control codes are doing the operations in the opposite order from the typewriter.
Turns out, the reasons are mechanical[1]:
>The separation of newline into two functions concealed the fact that the print head could not return from the far right to the beginning of the next line in time to print the next character. Any character printed after a CR would often print as a smudge in the middle of the page while the print head was still moving the carriage back to the first position. "The solution was to make the newline two characters: CR to move the carriage to column one, and LF to move the paper up.
Aha! Makes sense.
In a way, this was creating a de-facto protocol by usage, in a similar spirit the the author is suggesting to get rid of it.
As in: the existing standard wasn't really supported, but letting the commands go through nevertheless and allowing things to break incentivized people to collectively stick to the way of doing things that didn't result in misprints.
>the lever would do LF, and pushing on it further would do CR (tensioning the carriage spring).
In any case, carriage return is just as important function of the lever as line feed:
- you can also directly do line feed by turning the roller
- line feed, by itself, doesn't need a large lever
- carriage return, by itself, doesn't need a large lever either - you can simply push the carriage
- however, having a large lever is an ergonomic feature which allows you to:
1) return the carriage without moving your hands too far from the keyboard
2) do CRLF in one motion without it feeling like two things
3) If needs be, do a line feed by itself, since the force required for that is much smaller compared to the one to move the carriage (lever advantage!).
The long lever makes it so that line feed happens before carriage return. If the lever were short, you'd be able to move the carriage until it stops, and only then would the paper move up.
So I wondered why the control codes are doing the operations in the opposite order from the typewriter.
Turns out, the reasons are mechanical[1]:
>The separation of newline into two functions concealed the fact that the print head could not return from the far right to the beginning of the next line in time to print the next character. Any character printed after a CR would often print as a smudge in the middle of the page while the print head was still moving the carriage back to the first position. "The solution was to make the newline two characters: CR to move the carriage to column one, and LF to move the paper up.
Aha! Makes sense.
In a way, this was creating a de-facto protocol by usage, in a similar spirit the the author is suggesting to get rid of it.
As in: the existing standard wasn't really supported, but letting the commands go through nevertheless and allowing things to break incentivized people to collectively stick to the way of doing things that didn't result in misprints.
____ [1] https://en.wikipedia.org/wiki/Newline