I have not done any research in Ritchie's PhD thesis, but just as a general hint on the research: besides typewriters there were of course (foto-)typesetting systems at the time capable of producing the output. The Berthold Diatype, for example, dates back to 1952 and would have been able to produce the formulars. It would have required painstaking preparation and a very experienced typesetter - but, possible. Interestingly, Berthold introduced an internal metric system for their fototypesetters of 48 units (in relation to the metrics of the hot metal body), fitting quite nicely with the 1/12 grid.<p>That said, it does not at all seem likely to me and I am fully into the typewriter theory. Berthold was not very common in the US and it would have been very expensive. But there were similar systems of US origin and I think other possibilities should be investigated, mentioned and explicitely ruled out. Even metal type must be considered!<p>Regarding the effort and costs:<p>During my apprenticeship as a fototype-setter on Berthold systems in the 80s, my girlfriend graduated from senior highschool with a thesis work about colorized photography (analogue of course ;-). I was very passionate about typesetting during my apprenticeship and my dedication was rewarded with free access to all tools, typesetting machines and even the expensive photo papers and film for private use as long as it was in my spare time. So I typesetted the thesis work of my gf on large A3 photopaper in a nice font on a Berthold ads 3000 and she would glue the hand-colorized photographs on it. The result looked better than any photobook you could buy at the time and it was way over top for the requirements of the thesis work.<p>So there is no reason to dismiss a possibility just on the assumption, that it would have been too expensive or too much of an effort. Sometimes it only requires a personal relation to make something seemingly impossible happen.
Mentioned here:
UNIX: A History and a Memoir
<a href="https://www.rulit.me/data/programs/resources/pdf/UNIX-A-History-and-a-Memoir_RuLit_Me_616356.pdf" rel="nofollow">https://www.rulit.me/data/programs/resources/pdf/UNIX-A-Hist...</a><p>5.3 Early Formatters<p>The problem was that there was no interactive
computer system like CTSS at Princeton; there weren’t any computer termi-
nals either. All that was available was punch cards, which only supported
upper case letters. I wrote Roff in Fortran (far from ideal, since Fortran was
meant for scientific computation, not pushing characters around, but there
were no other options) and I added a feature to convert everything to lower
case while automatically capitalizing the first letter of each sentence. The
resulting text, now upper and lower case, was printed on an IBM 1403 printer
that could print both cases. Talk about bleeding edge! My thesis was three
boxes of cards. Each box held 2,000 cards, was about 14 inches (35 cm) long
and weighed 10 pounds (4.5 kg). The first 1,000 cards were the program and
the other 5,000 were the thesis itself in Roff.
Nothing about his thesis suggests that it was done using anything except a typewriter and some engineering (drafting)stencils in common use at the time. Typewriters are capable of arbitrary character alignment (and even rotation with clever abuse of the paper) and engineering stencils were in common usage for all common symbolic figures.<p>I have produced documents with similar and more complex features using those tools, and Ritchie’s accuracy, although more than sufficient, is unremarkable for someone adept with those tools.<p>In the analog world, the mechanical and repetitive default spacing of the typewriter was the intrusion, not the ontological rule.<p>The re-production of the document in its various iterations is remarkable, but consistent with using a layout table (written notes of calculated alignments). It was a common method used to calculate the original spacing for awkward or critical text. You couldn’t just type something and then move it, so you would work it out ahead of time before typing. If you were smart or experienced you would note these calculations as a list of alignments so you could reuse them when you inevitably had to start over. There is no reason to suspect that these alignment notes would not have been reused and iterated upon.<p>He might easily have done this himself, and certainly would not have found it difficult to find someone with the skills to do so. The fact that most people didn’t bother speaks more to the perceived importance of doing so rather than the physical capability to produce the work artfully using common tools.<p>He either considered it important to do it somewhat artfully or someone helping him did. It’s no more complex than that.
<i>We have no idea how it would even be possible to make these horizontal adjustments with the typing machines of the time.</i><p>I agree with the other comment here that the authors haven't used a typewriter, or at least in enough detail to know that on many if not all of them, holding down the spacebar will advance the carriage by half a character (and releasing it, in normal use, advances the other half.)
I'm curious why they haven't done more forensic typographic analysis of the fonts themselves. There are a number of images of actual Selectric fonts, including [1], and that includes symbols and other variations. Close examination would either confirm the use of that equipment, or else discrepancies would be a valuable clue.<p>Thomas Phinney, Font Detective[2] is the first person I'd ask, as he's done this professionally, though I have done a bit of it myself.<p>[1]: <a href="http://luc.devroye.org/fonts-44934.html" rel="nofollow">http://luc.devroye.org/fonts-44934.html</a><p>[2]: <a href="https://thefontdetective.com/" rel="nofollow">https://thefontdetective.com/</a>
It seems that the author never used a typewriter! The typewriter has tabs, so that you can center the equal sign, for example, after 3 tabs, and the alignment will be perfect each time. Most probably Dennies Richie sent his manuscript to a professional typist who provided services to the university, unless he was adept at spend several hours typing until he got professional results.
The actual PhD thesis[pdf], the topic of discussion:<p><a href="https://archive.computerhistory.org/resources/access/text/2020/05/102790971/Ritchie_dissertation.pdf" rel="nofollow">https://archive.computerhistory.org/resources/access/text/20...</a><p>Found here [0] with two copies archived:<p>* Dennis Ritchie’s personal copy [1]<p>* Albert Meyer’s copy [2]<p>[0] <a href="https://computerhistory.org/blog/discovering-dennis-ritchies-lost-dissertation/" rel="nofollow">https://computerhistory.org/blog/discovering-dennis-ritchies...</a><p>[1] <a href="https://www.computerhistory.org/collections/catalog/102784979" rel="nofollow">https://www.computerhistory.org/collections/catalog/10278497...</a><p>[2] <a href="https://www.computerhistory.org/collections/catalog/102790971" rel="nofollow">https://www.computerhistory.org/collections/catalog/10279097...</a>
For sake of reference, in the 1950s my parents both took their theses to a typist, which was the standard operating procedure. You could do it yourself, but multiple copies were needed, and only a typist could do it accurately enough to trust themselves with carbon paper. Correcting mistakes on carbons was a mess.<p>Chemical diagrams, graphs, and equations, were all done by hand.<p>Theses were shorter.
"The braces are not perfect— clearly they have been done by hand—but they are very precise"<p>There were plastic template stencils/rulers that let you draw great looking braces.
Looking through all of this, my own theory is "grotty hack". An extremely capable programmer, with access to all kinds of toys. Doesn't want to write or improve a world-beating document formatter, just get the document printed.<p>You can justify paragraphs easily enough with a simple program. As for the sub/superscripts, why not just annotate something like blah[up]blahblah[up]blah[down][down] etc. and then do a hacky preformatter that sorts all of this into microspaced lines. Print the stuff at each height in one pass, go down a microstep, print the next and so on. He did have a Selectric-type machine available driven by a computer in his basement after all.<p>What do you do with a grotty one-off hack once it's done its job? Bury it. Don't mention it in a workplace full of geniuses who would write something like "troff" just to make a point. Especially because they did do that only a few years later. Doesn't solve the mystery of why he didn't bother to go through with the PhD of course.
This is a non-mystery. It looks like this was done with a Selectric typewriter using two typeballs, one of them "Symbols 10", and the other for text.[1]<p>The reason there are two versions of "4" is because you could type something like
"(4.10)" with either the regular typeball or the Symbols ball. Both have numbers, parentheses, upper case letters, and a period/decimal point. Switching typeballs takes a few seconds, so it's only done when necessary.<p>There was a little lever on some Selectrics which displaced the carriage horizontally by half a space.[2] So, if you really needed half spacing, it was available. But you had to hold the spring-loaded lever in place while typing, so this was rarely used. It was used for fixing typos by erasing two characters and squeezing in three. It was also possible to move the paper a half-line vertically.<p>This is tedious work, and there were pro typists who did it for money. This was a manual job.<p>All this is on Google.<p>[1] <a href="https://www.duxburysystems.org/downloads/library/texas/apple/cnthesis/selectric.htm" rel="nofollow">https://www.duxburysystems.org/downloads/library/texas/apple...</a><p>[2] <a href="https://en.wikipedia.org/wiki/IBM_Selectric_typewriter" rel="nofollow">https://en.wikipedia.org/wiki/IBM_Selectric_typewriter</a>
>This strange set of circumstances raises at least three broad questions ...<p>>- Why wasn't the degree granted?"<p>According to [1]<p>"in 1968, he defended his PhD thesis on "Computational Complexity and Program Structure" at Harvard under the supervision of Patrick C. Fischer. However, Ritchie never officially received his PhD degree as he did not submit a bound copy of his dissertation to the Harvard library, a requirement for the degree."<p>So he had bigger and better things to do than mere filing. Plausible!<p>[1] <a href="https://en.m.wikipedia.org/wiki/Dennis_Ritchie#:~:text=However%2C%20Ritchie%20never%20officially%20received,a%20requirement%20for%20the%20degree" rel="nofollow">https://en.m.wikipedia.org/wiki/Dennis_Ritchie#:~:text=Howev...</a>.
I thought that his thesis disappeared because he had military connections and this stuff was too good to share with potential enemies. That would also explain how he could white-out and copy a document before xerox became widely available. The military probably had early access to the technology needed to duplicate documents, such as maps or code tables.
The Wikipedia page on LOOP [1] contains an excellent overview of the very simple language that is the subject of Dennis' thesis, and that turns out to be equivalent in expressive power to primitive recursive functions.<p>Curiously, one of the instructions in Dennis' original formualtion, namely the assignment X = Y of the value in one register to another, turns out to be redundant, as it it also achieved by<p><pre><code> X = 0
LOOP Y
X = X + 1
END
</code></pre>
Btw, this example shows the entire repertoire of instructions available in LOOP, namely set to 0, increment, sequential composition, and looping. The method of obtaining a predecessor function<p><pre><code> TMP = 0
LOOP X
Y = TMP
TMP = TMP + 1
END
</code></pre>
reminds me of a similar solution for the Church numerals in lambda calculus [2].<p>[1] <a href="https://en.wikipedia.org/wiki/LOOP_(programming_language)" rel="nofollow">https://en.wikipedia.org/wiki/LOOP_(programming_language)</a><p>[2] <a href="https://en.wikipedia.org/wiki/Church_encoding#Derivation_of_predecessor_function" rel="nofollow">https://en.wikipedia.org/wiki/Church_encoding#Derivation_of_...</a>
Why is it called T/Roff? Because of NROFF.<p>Why is NROFF called NROFF? Because of RUNOFF.<p>Why did DEC call it RUNOFF? because there was a strong tendency to short names for commands. 6 letters in 6 bit notation fit in a 36 bit word: the Dec-10 which had runoff, had 36 bit words.<p>RUNOFF begat NROFF begat TROFF begat DITROFF<p>OFFset printing. Indirect transfer of the image to paper from a plate, which can be photo-litho exposed.<p>If you can control the phototypesetter, you can print at higher quality than you can type.
> A Typographical Mystery<p>I suspect many people here just haven't used typewriters extensively. You can adjust how the paper is put in before you start typing. You can move it up a little, over a little, etc.<p>You can type the whole thing without subscripts, then put the paper in a second time, adjust it a bit and get all your subscripts.<p>All you need is a repeatable spacing template. And that is easy to do with transparent paper. With three different pieces of parchment paper, you can get three different repeatable levels (regular, subscript, superscript) fairly easily - you just run the paper thru 3 times. Align it, then pull the parchment paper out.<p>You can do the same thing vertically so you get nice repeatable grids.<p>It's a lot of work, but not a "mystery".
Maybe a time traveler.<p>Remember, there were people scraping the Internet looking for things that were posted that might indicate someone was a time traveler?<p>Maybe Dennis Ritchie was given some advanced information and given access to advanced technology (US security service that someone else mentioned)?<p>Something fun to think about.
Well, given a pdp-11, runoff, a tulip-wheel printer, a 300- (maybe 1200, forget) baud modem and a pile of 25% rag dissertation paper you too can create a dissertation. Sorta tedious but it worked.
I wonder if there are more examples of extra spacing in the thesis after correction. It may be evidence the thesis was done on punched cards which were duplicated and corrected. I produced a simple program with no maths only a couple of years later that made up a contents list and attempted spacing the words to get even lines and stop having just a single line of a paragraph on a page and a few things like that but, the output was to a lineprinter so I never thought of doing anything fancy. It did its own spacing so it wouldn't suffer that problem except where the spacing for a section was explicit. The contents list was printed at the end and you moved it to the beginnng yourself :-) I would guess a lot of people did that sort of thing then.
What's fascinating to me is that it appears that he fulfilled the scholarly requirements for a doctorate (including completing a dissertation that his committee signed off on) but didn't fully complete the bureaucratic/administrative requirements. The proposed explanation is that he already had a job, was busy with other things, and didn't really care.<p>If this is the case, then unless Ritchie really didn't want the Ph.D. (or was trying to make some kind of statement) it seems to me that his advisor kind of dropped the ball by not getting his student a bit of administrative help to actually receive the degree.
The DR. Jupiter hypothesis:<p>FOURier analysis of the Poisson distribution of DR's thesis
hints at the possibility that had Bob Bemer[0] been able to golf ASCII,<p>DR might have joined the selectra golf club and forgone the unix/multics debate. aka made full use of the Magnetic Tape Selectric Typewriter (MT/ST) model.<p>if "Mathematicians Complete Quest to Build ‘Spherical Cubes’"[1] had just been available to Bob Bemer....<p>[0] : <a href="https://www.ibm.com/ibm/history/ibm100/us/en/icons/selectric/" rel="nofollow">https://www.ibm.com/ibm/history/ibm100/us/en/icons/selectric...</a><p>[1] : <a href="https://www.quantamagazine.org/mathematicians-complete-quest-to-build-spherical-cubes-20230210/" rel="nofollow">https://www.quantamagazine.org/mathematicians-complete-quest...</a>
I saw this video: <a href="https://www.youtube.com/watch?v=82TxNejKsng">https://www.youtube.com/watch?v=82TxNejKsng</a>.<p>Something more sinister is alluded to. Especially that the faculty will never reward a degree to Richie. The video doesn't give a definitive explanation, however.<p>But let me give a very wild speculation: Someone suspected plagiarism or just something to be off. That person might have seen a draft copy and thought to himself, this can't be right. They started an investigation. And Ritchie, being a young man really did something bad, perhaps "lending" something. It might be even something not directly related to the thesis. Ritchie was caught red-handed and the punishment was threatening to reject the thesis. Being told this Ritchie didn't submit the thesis. Because shame was involved he never talked about it.<p>Sorry to be such a downer. If this is true, this would be a very sad story of injustice. Perhaps the dean (or similar) was just too strict and powerful and hated Ritchie. The punishment was too severe. Now both are dead and took their stories to the grave. At least, Ritchie had a successful career anyway, and for that I am happy.<p>It's only a speculation based on the video I saw. Caveat emptor.
Larger samples with grids overlayed are available at <a href="https://dmrthesis.net/dmr-thesis/" rel="nofollow">https://dmrthesis.net/dmr-thesis/</a>
You can get a quick look, visually, here: <a href="https://www.cs.princeton.edu/~bwk/dmr/" rel="nofollow">https://www.cs.princeton.edu/~bwk/dmr/</a><p>Crazy for 1968. I guess he and Donald Knuth will have a lot to talk about in the after life!
Reading it the obvious way I'd have done the job at the time would be to do two or even four prints on each page selecting which chracers fell on that gride each time. The thesis would be written using LISP to do the formatting. This would also only print those characters that fell on the current alignment.
It would be a bit fiddly making the 1/24 inch alignments of the pages and I'm sure there would have been plenty of mistakes! But it is straightforwardly doable with the tools he had. Very impressive though. If he did have a LISP program like that I'd have expect him to have developed it further or make some mention of it.
The paper posed three questions but only cater for the last one i.e. on the how was the thesis prepared?<p>It'd be very interesting to see further research on the very first question regarding the contributions elements of the thesis due to the overwhelming popularity of the C programming languages that most of the popular modern programming languages are based upon it including C++, Matlab, Java, Python, Ruby, C#, D, Go, Swift, Rust and even the latest proposed TenetLang programming language by GPT-4 [1].<p>[1]GPT-4 Designed a Programming Language:<p><a href="https://news.ycombinator.com/item?id=35177857" rel="nofollow">https://news.ycombinator.com/item?id=35177857</a>
I want to know about the interface of the typewriter/ printer he was working off of. Also what kinds of stencil guides were available at the time. My hot take after reading it: Did he have some way of 'setting' the stencils directly onto the printer in a very controlled way and the ability to 'pause' printing?<p>IE, prints prints prints, pause, some stencil required, put in stencil into controlled space, make mark, remove stencil, press space bar, prints prints prints prints...<p>It might also explain the '+' issues. It might have been a very small stencil and less well fit into a stencil guide.
<i>> It appears that Dennis was able to replace incorrect copy with new text in the surrounding original copy, but note the extra space in the corrected version. Other than corrections, the January and February versions are identical in every way: February is not a new version, but a copy of the January draft except for corrections. ... The natural explanation is that he used white-out and a Xerox copy machine. Except that there have been no reports from anyone from this era that white-out / replace / Xerox editing treatment was possible at the precision and reproducibility seen here.</i><p>Could he have simply retyped the entire page?
Among all the fuss about typography, the authors have overlooked the most important detail about the PHD thesis, which was that Dennis Ritchie was the inventor of Brainfuck.
Failing to mention his involvement with the US security services seems like an oversight. We don't know exactly what technology he add access to at the time.
I think he just used a common all-mechanical typewriter. Every typewriter I used as a kid had a fractional form-feed of at least two steps (half a line), and some of them had horizontal rulers and even tabs on the carriage so you could accurately return it to any position you wanted. I loved drawing things with them by just moving the carriage around and re-aiming the typing aperture.
Is there an implication that his thesis wasn't actually produced in the year it was claimed to have been made, and in fact made much later? It sort of reads that way but I don't see any explicit mention of this in the paper or comments
I wonder how much would be an estimate for the cost for the University in terms of image and networking, of not allowing Dennis Richie to read their PhD there because a fee.