You are reading that right. If it makes it seem any more sane, that's because many text editors of the time weren't written for screens ("displays"), but for teletypes, where you couldn't possibly see your code verbatim as you were editing it.
For example, the standard editor on early Unix was 'ed'. It is available on most modern *nix systems, if you care to try it :). Bill Joy later modified ed to be a display editor, or 'vi'sual editor; so if you have you have used Vi, it shouldn't be too unfamiliar.
Well, ex is 'ex'tended ed, and vi and ex are the same program.
From 1976-1979, the way to open vi was to execute 'ex', and run the 'vi[sual]' command in ex. In 1979, ex learned to launch the 'vi' command automatically if argv[0] is "vi", and a symlink from 'bin/vi' to 'bin/ex' was added.
Someday, I hope someone will say "Am I reading this right? You used to not be able to see your code execute as you were editing it? My god, that sounds horrible."
There is a lot of technology advancement (in software and hardware) that we just take for granted today, and will tomorrow!
The story (in "software superheroes", thoroughly good read) is that the British computer scientist George Coulourais, was visiting Bell Labs and met with Ken Thompson. Ken was editing some of the unix code base using a 'ed'- with no reference printout, no display, just typing from memory. George was simply astounded and so christened his own editor (which used raw input to allow line by line editing) 'em' or Editor for Mortals
Subsequently he gave the code to Bill Joy who turned it into ex and then vi and at some point even Ken Thompson probably used it.
"Our" history (as coders) is short and surprisingly oral, but still has gods in it and messengers from the gods bringing down the fruits of their wisdom.
Have you ever used a 300bps modem to connect to the internet? If you did then you would see how avoiding rendering could make you much much more productive.
I had Emacs running "okay-ish" on my 300 baud modem. I wrote a terminal emulator that implemented character and line insert and delete, and region scroll, which made Emacs screen refresh (borderline) tolerable.
Let's just say that it WAS tolerable considering that my alternative was to use punchcards. (Imagine long lines for punchcard machines in the basement of the CS building, which smelled of too many students and way too much fear, and waiting six hours for your program to run. Oh, and everything in uppercase...)
If memory serves, one of Emacs innovations was to decouple the display system from the editing system. The display would run asynchronously. If the display lagged due to a slow connection it would always be trying to show the most current state rather than strictly rendering the results of each edit operation, one by one. It also tried to minimize the terminal codes need to bring the display up to date.
I can't say I've ever used it on a 300 baud modem, but I have used it over a transcontinental SSH session on a crowded wifi connection and I've been thankful for it being designed to operate well under adverse conditions like that.
Yes, I always assumed that was part of the motivation for "chunky" operations like forward/delete word, paragraph, etc. On a slow connection it made a big difference to be able to jump ahead by words, paragraphs, or "balanced expressions" rather than character-by-character. And VT100 terminals didn't have a mouse so there was no way to do something like click-drag to select a block of text.
If anyone using a Mac wants to experience this, there exists the retro terminal emulator "Cathode" which can emulate various modem speeds (along with curved glass, CRT phosphor persistence, etc) http://www.secretgeometry.com/apps/cathode/
It's still a very effective method of working with code. I dare you to find a display which will let you see (and edit) as much code as printouts laying on the floor would :)
https://en.wikipedia.org/wiki/File:ASR-33_at_CHM.agr.jpg
For example, the standard editor on early Unix was 'ed'. It is available on most modern *nix systems, if you care to try it :). Bill Joy later modified ed to be a display editor, or 'vi'sual editor; so if you have you have used Vi, it shouldn't be too unfamiliar.