7 ms·

> And that typed text is way, way cleaner than any typewriter I’ve seen. Pedantic point: electric typewriters (which have existed since the 1960s) do type in a

by derefr 2y ago

> And that typed text is way, way cleaner than any typewriter I’ve seen. Pedantic point: electric typewriters (which have existed since the 1960s) do type in a way that looks exactly like this. (In fact, note that the text on the real employee ID card, shown later in the article, doesn't look any less clean! It's just set in a different, narrower font.) The smudginess of mechanical typewriters comes from 1. them striking (and especially, releasing) at the same speed you're depressing the key, and 2. having many of the keys necessarily approach the ribbon from an angle. The keys being swung weakly by your fingers, also has the additional implication that the ink ribbons used in mechanical typewriters have to be soft and squishy (so: made of cloth), and use thin inks. These properties ensure a transfer from even a low-velocity impact. But the trade-off is that cloth ink ribbons transfer only a rough outline of what's struck; and thin inks are high-bleed inks. An electric typewriter, playing out a pre-buffered line with a crisp, predictable report, using linear actuators and a rotating-ball type-head to bang a tape ribbon loaded with high-viscosity ink onto the page, can create text indistinguishable from books/newspapers of the same period, or from modern laser-printer reproductions of the same font faces. They're essentially character-at-a-time letterpresses! (Also, ignoring electric typewriters for a sec: inks bleed more on thin, cheap paper. But this is [a forgery of] an employee ID card — where, for durability, a nice heavyweight paper or cardstock would have been used. You're always going to get a better-looking result inking such paper.)

anon946 2y ago
I have used multiple typewriters in my life, and agree. In addition, the look of film/tape vs cloth/nylon is very different, and tape ribbon can look very crisp: https://en.wikipedia.org/wiki/Ink_ribbon#Single-pass_(polymer)_ribbons https://en.wikipedia.org/wiki/Ink_ribbon#Single-pass_(polyme....
- joe_guy 2y ago
  Do you mind if I ask why you still use typewriters?
  - SoftTalker 2y ago
    For some things (e.g. a one-off need to address an envelope) they are still faster and easier than anything else.
    - Twisell 2y ago
      ...except a pen
      - Faaak 2y ago
        I don't think I would write faster with a pen than with a typewriter..?
        ghaff 2y ago
        Yes. But for the one off need described (or similar) it’s way faster to write an address than to get things set up with a typewriter. Of course for certain forms, better legibility in many cases may make it worth it.
        SoftTalker 2y ago
        Yes. Post Office OCR is pretty good, but deliverabilty of hand-addressed envelopes is not as good as with typewritten addresses. If you have really neat block printing it might be a wash.
  - talldatethrow 2y ago
    I bought one recently at an estate sale so that I could write things without the ability to open a window and browse the web.
    - Maxion 2y ago
      And, today, with LLMs it'll take you a few seconds to digitize the document, too. For this reason I've also been considering a typewriter...
jart 2y ago
This is one of those times when I wish Hacker News had something like Reddit Gold. Wonderful comment.
- fragmede 2y ago
  not the same thing but https://news.ycombinator.com/highlights https://news.ycombinator.com/highlights
- KennyBlanken 2y ago
  For a comment easily disproved by a simple google image search which returns plenty of examples of selectric output where the characters have anywhere to a very subtle but not perfect (like in the badge) alignment, to examples where the characters have "visible at arm's length" vertical and horizontal, and even rotational, issues?
  - ssl-3 2y ago
    Were those examples typed in 1977 on a fresh Selectric, or were they typed decades later on a tired Selectric? 1977 was a long time ago, even in typewriter years.
Aloha 2y ago
and an a Selectric II/III didnt use a felt ribbon, but rather a wax transfer.
- dreamcompiler 2y ago
  IBM called it a "carbon" ribbon.
  - antonvs 2y ago
    I used to use one, so I was curious. It was hard to find good info by googling, but I eventually came across a presentation which claimed that the Selectric carbon ribbon "consists of a carbon wax coating on a polyethylene base": https://www.scribd.com/presentation/419638824/typewriters https://www.scribd.com/presentation/419638824/typewriters (slide 21) Searching for those keywords came up with this, which uses the exact same wording: https://www.google.com/books/edition/Scientific_Examination_of_Questioned_Doc/nQlJw2_gE-cC?hl=en&gbpv=1&dq=selectric+ribbon+carbon+wax&pg=PA182&printsec=frontcover https://www.google.com/books/edition/Scientific_Examination_...
    - Aloha 2y ago
      So everyone is right?! Thats the best kind of correct. ;-)
Groxx 2y ago
Some nice up close content about some fancy electronic typewriters, from Technology Connections: https://youtu.be/YE0U018Copw https://youtu.be/YE0U018Copw
KennyBlanken 2y ago
> Pedantic point: electric typewriters (which have existed since the 1960s) do type in a way that looks exactly like this. Wrong. Literally gooogle "selectric type sample" and see dozens of examples of them not typing anywhere near in a perfect line. Maybe machines with very low hours or kept in excellent condition might have excellent spacing, but there's plenty of examples of them obviously not having perfect spacing. https://www.flickr.com/photos/nicksherman/14249132603 https://www.flickr.com/photos/nicksherman/14249132603 https://www.reddit.com/r/typewriters/comments/e7xxct/typeface_sample_of_the_1951_ibm_model_a_executive/ https://www.reddit.com/r/typewriters/comments/e7xxct/typefac... Another example where misalignment is even more obvious: https://www.reddit.com/r/typewriters/comments/sc519r/ibm_selectric_iii_670x_different_font_and_pitch/#lightbox https://www.reddit.com/r/typewriters/comments/sc519r/ibm_sel... http://www.jollinger.com/typewriters/typewriters/IBM_Selectric_II.html http://www.jollinger.com/typewriters/typewriters/IBM_Selectr... you can also see inconsistent letter spacing, more obvious on some fonts than others, but you can see some characters are connected and others aren't. And no, it's not just the position of the character relative to others on the ball. As the author points out, these characters have perfect vertical alignment. Then go look at high speed footage of the 'golfball' in action and you can see the substantial deflection caused by how fast and forceful the movements are. You can see the entire assembly is bouncing around as the rails it's on flex: https://www.youtube.com/watch?v=RTtKaqIpOJc https://www.youtube.com/watch?v=RTtKaqIpOJc
- masswerk 2y ago
  To be fair, the specimen shows some misalignment as well, e.g., the "S" at the very beginning is up and a bit to the left, the "Y" is shifted to the right, and there are small irregularities in "NGST", as well. However, I don't think that they add up in a sensible manner. Notably, the Red Cross invoice is much worse: additionally to what has been noted in the article already, why would you have a hyphen in "Verkäufername"? Also mind the reoccurring use of "#" for "Nummer", which would have been rather unacceptable in a formal German document.
  - KennyBlanken 2y ago
    The image provided is so low resolution that this is probably a side effect of the edges of the characters being on the boundary between pixels on the camera's sensor. Magnify it to full screen and you'll see what I'm talking about. Now go back and look at the samples I linked to, where you can clearly see vertical misalignment. I remember everyone in my school system had selectrics when I was a kid, and I assure you, they could produce text that was all over the place. Probably because the ones in a public school saw heavy use / were not properly maintained and serviced to the degree required.
deleted 2y ago
[deleted]
dkjaudyeqooe 2y ago
At least in the 80's, there were also printers that worked like that, ie a character ball plus some sort of transfer material to mark the page.
dreamcompiler 2y ago
> An electric typewriter, playing out a pre-buffered line with a crisp, predictable report, using linear actuators and a rotating-ball type-head to bang a tape ribbon loaded with high-viscosity ink onto the page The machine you just described is an IBM Composer, except the ribbon was not "high viscosity". Rather it was essentially solid, being a carbon ribbon with a mylar back. Most electric typewriters were not Composers, so they did not pre-buffer lines. In fact most electric typewriters were not Selectrics so they didn't even use a ball. The IBM Executive for example used swinging type bars just like a manual typewriter, and it produced excellent copy that was frequently used as a master for offset lithography. (Source: Me. I used to own a print shop.) The presence or absence of swinging type bars, pre-buffering, or balls makes no difference. Carbon ribbons and the repeatability of impression that electric provides are what matter.
- deleted 2y ago
  [deleted]
- antonvs 2y ago
  > Rather it was essentially solid, being a carbon ribbon with a mylar back. And produced the most crisp type imaginable. I'm not sure any laser printer can compete.
- deanishe 2y ago
  > so they didn't even use a ball Daisywheels were common, IIRC.
- derefr 2y ago
  Swinging type-bars in general weren't a problem; it was the kind of swinging type bars used in (later) "manual" mechanical typewriters that were. (And also, that's not what I mean by "buffered.") The oldest (late 1800s) mechanical typewriters were designed simply, with type mechanisms engineered under the assumption of a slow hunt-and-peck typist who would only be pressing one key at a time. And this worked well, until typing as a skill developed, and people began to activate keys concurrently (with one type-bar potentially beginning to swing forward, before a neighbouring type-bar finished its return.) This caused the neighbouring type blocks on the end of the bars to end up binding together — usually at the end of their bars' travel, causing both keys to remain stuck down. According to folk history, this type-bar-binding problem was solved in part through the development of the QWERTY layout — moving frequently-successive English-language letter-pairs so that they wouldn't be done using neighbouring keys. Regardless of the veracity of that, this still didn't truly solve the problem — early QWERTY typewriters still end up binding for many common words. Later mechanical-typewriter manufacturers sought to solve this problem "for real", through internal engineering tweaks. Look up patents from the early 1900s-1920s, and you'll see many of these proposed. But one two-part approach stood out, and became nearly-universally adopted: 1. chamfering and carbon-lubricating the edges of the type blocks on the end of the type-bars; and then 2. allowing the type-bar linkages a bit of horizontal travel. These two tweaks together, allowed the type blocks on the end of the type-bars to slip past one-another (at least when travelling at differing velocities, or with one rising and the other falling.) And this virtually eliminated binding — but not without trade-offs. Mechanical typewriters with these fixes, have a slight looseness to the type-bars, and so a slight random wobble in the horizontal placement of type on the page (especially when the key was depressed slowly). And if two neighbouring keys are depressed in quick succession, either one or both keys are liable to shove the other slightly, resulting in one having quite a bit of horizontal displacement, and even a slight "edge-on impact" where one side of the type doesn't get fully inked onto the page. These characteristics can be easily observed in type specimens from the early 1900s, to the point that they are often used to date such specimens. Nobody wanted to use these typewriters for professional typesetting if they could help it; they were just too "sloppy" at that point. (The earlier designs weren't, but the typebar-clash problem was just too bad for any "modern" professional typist of the era to volunteer to use them.) The introduction of electromechanical typewriters in general, allowed large changes to the type-bars and type, for the same reason that drive-by-wire in cars allowed large changes to the transmission and linkages: without a sloppy human in the circuit, things could be far more crisp. Key-clashes could be solved without mechanical slop; and so the mechanism could be tightened back up. At first, electromechanical typewriters — having nothing like a memory — were instead wired in a blocking fashion to avoid key-clashes. If you pressed two neighbouring keys in quick succession, the second key would "jam", refusing to depress until the first one returned. Essentially, all neighbouring pairs of keys were interlocked. This made typing on them very annoying — but required no fiddling to unstick, just a very attentive approach to typing, involving watching/feeling for unstruck keys, immediately stopping to re-key them. And the results were very crisp. So these typewriters were one of the first "enterprise hardware" — forced on typists (who didn't like them, but did tolerate them) by companies who wanted clean typed reports. The next natural step was to turn the blocking solution into a non-blocking / asynchronous one. This was done through one-key buffering — with the typewriter using two loops of analogue(!) https://en.wikipedia.org/wiki/Delay-line_memory https://en.wikipedia.org/wiki/Delay-line_memory as registers, to hold alternating key actuations and then play them back out. For most key actuations, this replay was instantaneous, with the electrical linkages to the type-bars being actuated concurrently. But neighbouring keys, again through electrical interlocks, would "put a hold on" their sibling key's replay (if that was the key struck) until their own replay was done. (One could compare/contrast these typewriter mechanisms with pinball-machine mechanisms, both being invented around the same time.) When digital electronics came along, the delay-line memories were now storing digital serial codes instead of parallel electrical voltages; and the number of bits able to be buffered and refreshed in the delay-line memory increased, so multiple keypresses of neighbouring keys, or the same key, could be buffered as fast as they could be pressed, and then replayed in sequence. (Some early computer TTYs were built using this sort of typewriter platform!) Some electronic typewriters in the late 1960s also switched from delay-line memory to the just-invented shift-register memory — which made them much more accessible to the mass-market, rather than only institutional buyers. And now we get to the original IBM Selectric Composer: it used magnetic tape for memory — and didn't immediately replay it, instead buffering indefinitely until you manually trigger replay. Which, mind you, isn't what made the Composer really good for printing. The thing that did that, was that the buffering allowed it to measure text and then typeset it using proportional-width type. But this actually required you to type everything twice (in immediate mode) or for it to read the magnetic tape twice (in buffered mode) — so really, the advancement here wasn't the memory, it was the compute. The ability of the Composer to accumulate the widths of keypresses, given a loaded table of widths of glyphs for the font in use, into an accumulator register, was what made "online" proportional typesetting possible. The Composer's use of external magnetic tape, also enabled the use of a cheaper sibling (the https://en.wikipedia.org/wiki/IBM_MT/ST https://en.wikipedia.org/wiki/IBM_MT/ST) to input the text and test-print it monospaced; while the Composer would just be used for proportional-type replay. In this use-case, the Composer itself was essentially playing the role of a typesetting machine, rather than a typewriter. But in terms of printing monospace text cleanly, the Composer wasn't any big advancement. Everything above since the first blocking-key electric typewriter was printing monospace text cleanly. Look at type from (expensive, niche) electrical typewriters from the 1930s on — they'll be crisp†. Telegrams from the period were printed on such machines, and look great. † Well, okay, there'll be some bleed; those ultra-crisp type edges did indeed only come along with polymer ink ribbons, and those were introduced/popularized along with the first Selectrics. But — presuming a fresh cloth ink ribbon — the type will always be fully inked, square on the page, not smudged, no wobble, no unwanted horizontal offset, etc. Mechanical-linkage typewriters had all of those problems! It's just that nobody really cared about any of that (other than those companies wanting really clean-looking reports), since nobody was doing offset-lithography mastering using monospace typefaces. It's only once the marketable use-case changed (with the Composer) that people really started to notice that typewriters had slowly become as good at producing a nice typeset page as a professional publishing house was.

by derefr 2y ago

anon946 2y ago

I have used multiple typewriters in my life, and agree. In addition, the look of film/tape vs cloth/nylon is very different, and tape ribbon can look very crisp: https://en.wikipedia.org/wiki/Ink_ribbon#Single-pass_(polymer)_ribbons https://en.wikipedia.org/wiki/Ink_ribbon#Single-pass_(polyme....

joe_guy 2y ago
Do you mind if I ask why you still use typewriters?
- SoftTalker 2y ago
  For some things (e.g. a one-off need to address an envelope) they are still faster and easier than anything else.
  - Twisell 2y ago
    ...except a pen
    - Faaak 2y ago
      I don't think I would write faster with a pen than with a typewriter..?
      - ghaff 2y ago
        Yes. But for the one off need described (or similar) it’s way faster to write an address than to get things set up with a typewriter. Of course for certain forms, better legibility in many cases may make it worth it.
        SoftTalker 2y ago
        Yes. Post Office OCR is pretty good, but deliverabilty of hand-addressed envelopes is not as good as with typewritten addresses. If you have really neat block printing it might be a wash.
- talldatethrow 2y ago
  I bought one recently at an estate sale so that I could write things without the ability to open a window and browse the web.
  - Maxion 2y ago
    And, today, with LLMs it'll take you a few seconds to digitize the document, too. For this reason I've also been considering a typewriter...

jart 2y ago

This is one of those times when I wish Hacker News had something like Reddit Gold. Wonderful comment.

fragmede 2y ago
not the same thing but https://news.ycombinator.com/highlights https://news.ycombinator.com/highlights
KennyBlanken 2y ago
For a comment easily disproved by a simple google image search which returns plenty of examples of selectric output where the characters have anywhere to a very subtle but not perfect (like in the badge) alignment, to examples where the characters have "visible at arm's length" vertical and horizontal, and even rotational, issues?
- ssl-3 2y ago
  Were those examples typed in 1977 on a fresh Selectric, or were they typed decades later on a tired Selectric? 1977 was a long time ago, even in typewriter years.

Aloha 2y ago

and an a Selectric II/III didnt use a felt ribbon, but rather a wax transfer.

dreamcompiler 2y ago
IBM called it a "carbon" ribbon.
- antonvs 2y ago
  I used to use one, so I was curious. It was hard to find good info by googling, but I eventually came across a presentation which claimed that the Selectric carbon ribbon "consists of a carbon wax coating on a polyethylene base": https://www.scribd.com/presentation/419638824/typewriters https://www.scribd.com/presentation/419638824/typewriters (slide 21) Searching for those keywords came up with this, which uses the exact same wording: https://www.google.com/books/edition/Scientific_Examination_of_Questioned_Doc/nQlJw2_gE-cC?hl=en&gbpv=1&dq=selectric+ribbon+carbon+wax&pg=PA182&printsec=frontcover https://www.google.com/books/edition/Scientific_Examination_...
  - Aloha 2y ago
    So everyone is right?! Thats the best kind of correct. ;-)

Groxx 2y ago

Some nice up close content about some fancy electronic typewriters, from Technology Connections: https://youtu.be/YE0U018Copw https://youtu.be/YE0U018Copw

KennyBlanken 2y ago

> Pedantic point: electric typewriters (which have existed since the 1960s) do type in a way that looks exactly like this. Wrong. Literally gooogle "selectric type sample" and see dozens of examples of them not typing anywhere near in a perfect line. Maybe machines with very low hours or kept in excellent condition might have excellent spacing, but there's plenty of examples of them obviously not having perfect spacing. https://www.flickr.com/photos/nicksherman/14249132603 https://www.flickr.com/photos/nicksherman/14249132603 https://www.reddit.com/r/typewriters/comments/e7xxct/typeface_sample_of_the_1951_ibm_model_a_executive/ https://www.reddit.com/r/typewriters/comments/e7xxct/typefac... Another example where misalignment is even more obvious: https://www.reddit.com/r/typewriters/comments/sc519r/ibm_selectric_iii_670x_different_font_and_pitch/#lightbox https://www.reddit.com/r/typewriters/comments/sc519r/ibm_sel... http://www.jollinger.com/typewriters/typewriters/IBM_Selectric_II.html http://www.jollinger.com/typewriters/typewriters/IBM_Selectr... you can also see inconsistent letter spacing, more obvious on some fonts than others, but you can see some characters are connected and others aren't. And no, it's not just the position of the character relative to others on the ball. As the author points out, these characters have perfect vertical alignment. Then go look at high speed footage of the 'golfball' in action and you can see the substantial deflection caused by how fast and forceful the movements are. You can see the entire assembly is bouncing around as the rails it's on flex: https://www.youtube.com/watch?v=RTtKaqIpOJc https://www.youtube.com/watch?v=RTtKaqIpOJc

masswerk 2y ago
To be fair, the specimen shows some misalignment as well, e.g., the "S" at the very beginning is up and a bit to the left, the "Y" is shifted to the right, and there are small irregularities in "NGST", as well. However, I don't think that they add up in a sensible manner. Notably, the Red Cross invoice is much worse: additionally to what has been noted in the article already, why would you have a hyphen in "Verkäufername"? Also mind the reoccurring use of "#" for "Nummer", which would have been rather unacceptable in a formal German document.
- KennyBlanken 2y ago
  The image provided is so low resolution that this is probably a side effect of the edges of the characters being on the boundary between pixels on the camera's sensor. Magnify it to full screen and you'll see what I'm talking about. Now go back and look at the samples I linked to, where you can clearly see vertical misalignment. I remember everyone in my school system had selectrics when I was a kid, and I assure you, they could produce text that was all over the place. Probably because the ones in a public school saw heavy use / were not properly maintained and serviced to the degree required.

deleted 2y ago

[deleted]

dkjaudyeqooe 2y ago

At least in the 80's, there were also printers that worked like that, ie a character ball plus some sort of transfer material to mark the page.

dreamcompiler 2y ago

> An electric typewriter, playing out a pre-buffered line with a crisp, predictable report, using linear actuators and a rotating-ball type-head to bang a tape ribbon loaded with high-viscosity ink onto the page The machine you just described is an IBM Composer, except the ribbon was not "high viscosity". Rather it was essentially solid, being a carbon ribbon with a mylar back. Most electric typewriters were not Composers, so they did not pre-buffer lines. In fact most electric typewriters were not Selectrics so they didn't even use a ball. The IBM Executive for example used swinging type bars just like a manual typewriter, and it produced excellent copy that was frequently used as a master for offset lithography. (Source: Me. I used to own a print shop.) The presence or absence of swinging type bars, pre-buffering, or balls makes no difference. Carbon ribbons and the repeatability of impression that electric provides are what matter.

deleted 2y ago
[deleted]
antonvs 2y ago
> Rather it was essentially solid, being a carbon ribbon with a mylar back. And produced the most crisp type imaginable. I'm not sure any laser printer can compete.
deanishe 2y ago
> so they didn't even use a ball Daisywheels were common, IIRC.
derefr 2y ago
Swinging type-bars in general weren't a problem; it was the kind of swinging type bars used in (later) "manual" mechanical typewriters that were. (And also, that's not what I mean by "buffered.") The oldest (late 1800s) mechanical typewriters were designed simply, with type mechanisms engineered under the assumption of a slow hunt-and-peck typist who would only be pressing one key at a time. And this worked well, until typing as a skill developed, and people began to activate keys concurrently (with one type-bar potentially beginning to swing forward, before a neighbouring type-bar finished its return.) This caused the neighbouring type blocks on the end of the bars to end up binding together — usually at the end of their bars' travel, causing both keys to remain stuck down. According to folk history, this type-bar-binding problem was solved in part through the development of the QWERTY layout — moving frequently-successive English-language letter-pairs so that they wouldn't be done using neighbouring keys. Regardless of the veracity of that, this still didn't truly solve the problem — early QWERTY typewriters still end up binding for many common words. Later mechanical-typewriter manufacturers sought to solve this problem "for real", through internal engineering tweaks. Look up patents from the early 1900s-1920s, and you'll see many of these proposed. But one two-part approach stood out, and became nearly-universally adopted: 1. chamfering and carbon-lubricating the edges of the type blocks on the end of the type-bars; and then 2. allowing the type-bar linkages a bit of horizontal travel. These two tweaks together, allowed the type blocks on the end of the type-bars to slip past one-another (at least when travelling at differing velocities, or with one rising and the other falling.) And this virtually eliminated binding — but not without trade-offs. Mechanical typewriters with these fixes, have a slight looseness to the type-bars, and so a slight random wobble in the horizontal placement of type on the page (especially when the key was depressed slowly). And if two neighbouring keys are depressed in quick succession, either one or both keys are liable to shove the other slightly, resulting in one having quite a bit of horizontal displacement, and even a slight "edge-on impact" where one side of the type doesn't get fully inked onto the page. These characteristics can be easily observed in type specimens from the early 1900s, to the point that they are often used to date such specimens. Nobody wanted to use these typewriters for professional typesetting if they could help it; they were just too "sloppy" at that point. (The earlier designs weren't, but the typebar-clash problem was just too bad for any "modern" professional typist of the era to volunteer to use them.) The introduction of electromechanical typewriters in general, allowed large changes to the type-bars and type, for the same reason that drive-by-wire in cars allowed large changes to the transmission and linkages: without a sloppy human in the circuit, things could be far more crisp. Key-clashes could be solved without mechanical slop; and so the mechanism could be tightened back up. At first, electromechanical typewriters — having nothing like a memory — were instead wired in a blocking fashion to avoid key-clashes. If you pressed two neighbouring keys in quick succession, the second key would "jam", refusing to depress until the first one returned. Essentially, all neighbouring pairs of keys were interlocked. This made typing on them very annoying — but required no fiddling to unstick, just a very attentive approach to typing, involving watching/feeling for unstruck keys, immediately stopping to re-key them. And the results were very crisp. So these typewriters were one of the first "enterprise hardware" — forced on typists (who didn't like them, but did tolerate them) by companies who wanted clean typed reports. The next natural step was to turn the blocking solution into a non-blocking / asynchronous one. This was done through one-key buffering — with the typewriter using two loops of analogue(!) https://en.wikipedia.org/wiki/Delay-line_memory https://en.wikipedia.org/wiki/Delay-line_memory as registers, to hold alternating key actuations and then play them back out. For most key actuations, this replay was instantaneous, with the electrical linkages to the type-bars being actuated concurrently. But neighbouring keys, again through electrical interlocks, would "put a hold on" their sibling key's replay (if that was the key struck) until their own replay was done. (One could compare/contrast these typewriter mechanisms with pinball-machine mechanisms, both being invented around the same time.) When digital electronics came along, the delay-line memories were now storing digital serial codes instead of parallel electrical voltages; and the number of bits able to be buffered and refreshed in the delay-line memory increased, so multiple keypresses of neighbouring keys, or the same key, could be buffered as fast as they could be pressed, and then replayed in sequence. (Some early computer TTYs were built using this sort of typewriter platform!) Some electronic typewriters in the late 1960s also switched from delay-line memory to the just-invented shift-register memory — which made them much more accessible to the mass-market, rather than only institutional buyers. And now we get to the original IBM Selectric Composer: it used magnetic tape for memory — and didn't immediately replay it, instead buffering indefinitely until you manually trigger replay. Which, mind you, isn't what made the Composer really good for printing. The thing that did that, was that the buffering allowed it to measure text and then typeset it using proportional-width type. But this actually required you to type everything twice (in immediate mode) or for it to read the magnetic tape twice (in buffered mode) — so really, the advancement here wasn't the memory, it was the compute. The ability of the Composer to accumulate the widths of keypresses, given a loaded table of widths of glyphs for the font in use, into an accumulator register, was what made "online" proportional typesetting possible. The Composer's use of external magnetic tape, also enabled the use of a cheaper sibling (the https://en.wikipedia.org/wiki/IBM_MT/ST https://en.wikipedia.org/wiki/IBM_MT/ST) to input the text and test-print it monospaced; while the Composer would just be used for proportional-type replay. In this use-case, the Composer itself was essentially playing the role of a typesetting machine, rather than a typewriter. But in terms of printing monospace text cleanly, the Composer wasn't any big advancement. Everything above since the first blocking-key electric typewriter was printing monospace text cleanly. Look at type from (expensive, niche) electrical typewriters from the 1930s on — they'll be crisp†. Telegrams from the period were printed on such machines, and look great. † Well, okay, there'll be some bleed; those ultra-crisp type edges did indeed only come along with polymer ink ribbons, and those were introduced/popularized along with the first Selectrics. But — presuming a fresh cloth ink ribbon — the type will always be fully inked, square on the page, not smudged, no wobble, no unwanted horizontal offset, etc. Mechanical-linkage typewriters had all of those problems! It's just that nobody really cared about any of that (other than those companies wanting really clean-looking reports), since nobody was doing offset-lithography mastering using monospace typefaces. It's only once the marketable use-case changed (with the Composer) that people really started to notice that typewriters had slowly become as good at producing a nice typeset page as a professional publishing house was.