Now, modern printers tend to use LCDs (which some higher-end old printers did) or web configuration interfaces, but this is far more clever, IMO.
When you used this menu, you lifted the top cover off. It would print the setting and its possible values, and then move the page up, such that the first value was right above the printhead - the printhead acted as a cursor. Select a value, it'd pull the page back down, overstrike the selected value for emphasis, and move to the next setting.
Also, why did I change NLQ and graphics to uni-directional printing? Dot matrix printers aren't as precise as their manufacturers would like, and banding can occur in bi-directional mode (especially in graphics) as a result.
Oh, and NLQ or "near letter quality" is a marketing (bullshit) term.
A 9-pin dot matrix printer is fundamentally a 72 vertical dpi device - the printhead has 9 pins in a vertical row, those 9 pins print a 1/8" thick horizontal line. (Note that horizontal resolution is just a matter of how precisely you can position the printhead - the Epson FX-80 set a 240 dpi standard there.)
However, if you can precisely step the platen, you can restrike characters and improve resolution.
Conveniently, the Epson printers supported stepping in increments of 1/216", or 1/3 of a pin (this also became a standard for 9-pin printers). So, "near letter quality" is achieved by simply printing each line two or three times to fill in the gaps between pixels.
That's fine and all, but if this is "near letter quality", what is "letter quality"? That's the output you'd expect from an IBM Selectric typewriter, which looks like this: http://bhtooefr.org/files/SelectricSampleMastodon.pdf
Go back to the first toot in this thread, look at that test page - all of the fonts except for "Draft" and "High Speed Draft" are NLQ fonts.
That's legitimately a massive improvement over the draft font, but it's still obviously printed.
24-pin dot matrix printers had far better resolution - 180 vertical dpi - and were often marketed as "letter quality" as a result. (Note that they could double resolution to 360 through double-striking, too. This made them far closer to actual letter quality.)
@ajroach42 I just wish I had a 24-pin printer handy to demonstrate what those can do, really.
A lot of people stuck with 9-pin because... realistically, going back to the tagline from the first toot, it really was all you *needed* back then, and it was far cheaper and more durable than 24-pin. (24-pin was developed by Japanese printer manufacturers, because CJK scripts really do need the higher resolution.) By the time Westerners needed more than a 9-pin, inkjets had far surpassed dot matrix.
@EdS Absolutely - that was the way to get true letter quality, cheaply, from a computer, without quibbling over whether it's "near" letter quality or it just is letter quality.
Problem: graphics, which people wanted to print.
Dot matrix could trivially do graphics, daisywheel... well, you could hammer the . character repeatedly...
This wasn't really settled until laser printers became affordable - daisywheel quality with better graphics than dot matrix.
@EdS Even early inkjets weren't quite daisywheel/golfball quality - they were in the same 360x360 dpi ballpark as a double-striking 24-pin dot matrix.
(The biggest strength of inkjet tech over 24-pin dot matrix was color, really. Dot matrixes could do it, but were bad at it, as color ribbons were expensive, and quickly cross-contaminated the colors (you can see it in the yellow areas of the test page). Color quality was generally pretty terrible, too, outside of the CMY and RGB primary colors.)
"Whose printer can print 132 columns at 500 lines per minute with a MTBF in excess of 3,000 hours for less than $5,500? What one machine can print 1200 lines a minute or plot at three inches per second with dual array density? What plotter uses the world’s most powerful electrostatic plotting software?
Versatec has it all. More models. Better print and plot quality. The best price/performance ratio in the industry.
Fan-fold paper output stacks neatly and automatically in basket."
@EdS Oh, that's sexy. Looks like the paper was proprietary, though, and it looks like laser printers using normal paper with heat fusing began to be available in the same era.
(I think this is the document you got that quote from? https://archive.org/details/TNM_Electrostatic_Printers__Plotters_-_Versatec__20170915_0165)
(Yes, that's the doc! I was at the 500 char limit.) From slightly earlier days I remember dye sublimation printers. I suppose they would have been used for presentations or posters. The electrostatic wide-beds were used for chip layout plots. Also used were felt pen plotters, later inkjets. I remember an early laser printer, and the improbability of PostScript being a full-on programming language.