DMR's Thesis: Unpacking an Enigma | Hacker News Reader

DMR's Thesis: Unpacking an Enigma

dmrthesis.net

53 pointssritchie13 comments

This explains the motivation to get roff working on the PDP-11. These expensive research machines being used as word processors--when there's perfectly good secretaries down the hall at Bell Labs--seems not a natural idea but to DMR it was.

> At the time of the placement of the order for the PDP-11, it had seemed natural, or perhaps expedient, to promise a system dedicated to word processing. During the protracted arrival of the hardware, the increasing usefulness of PDP-7 Unix made it appropriate to justify creating PDP-11 Unix as a development tool, to be used in writing the more special-purpose system. By the spring of 1971, it was generally agreed that no one had the slightest interest in scrapping Unix. Therefore, we transliterated the roff text formatter into PDP-11 assembler language, starting from the PDP-7 version that had been transliterated from McIlroy's BCPL version on Multics, which had in turn been inspired by J. Saltzer's runoff program on CTSS. In early summer, editor and formatter in hand, we felt prepared to fulfill our charter by offering to supply a text-processing service to the Patent department for preparing patent applications. At the time, they were evaluating a commercial system for this purpose; the main advantages we offered (besides the dubious one of taking part in an in-house experiment) were two in number: first, we supported Teletype's model 37 terminals, which, with an extended type-box, could print most of the math symbols they required; second, we quickly endowed roff with the ability to produce line-numbered pages, which the Patent Office required and which the other system could not handle.

Source, search for "roff": http://webarchive.loc.gov/all/20100506231949/http://cm.bell-...

There are a lot of complications with the story. The thesis was typed in January 1968 which was before Multics became operational, before PDP-11s. Neither Ken Thompson nor Doug McIlroy (nor Brian Kernighan), remember Dennis ever talking about working on his thesis... and people who know Selectrics and 2741 Terminals say that the machines were not set up to automatically type what appears in the dmr thesis, there had to be hand adjustments. You worked at the Labs during this period? Can you write me at billr@thinkfun.com ? Great link to reference paper!

Not me, just a good search hit.

I wasn't suggesting roff was used for the thesis, just that there were probably a bunch of motivated people who wanted to see roff succeed even if it was a hard sell to management.

Makes sense...

Could dmr have used a Model 37 teletype [1] to print his thesis?

It had two key features [2]: half-line vertical spacing control and a 128-character typebox that included mathematical symbols [3].

I reckon that a Model 37 could handle nearly all of the formatting seen in dmr's thesis automatically. If he didn't use a Model 37, he must surely have used a similar machine which also provided half-line vertical spacing control.

[1] https://en.wikipedia.org/wiki/Teletype_Model_37

[2] https://archive.org/details/TNM_Model_37_terminal_product_ca...

[3] https://minnie.tuhs.org/cgi-bin/utree.pl?file=V3/man/man7/gr...

These are things needed, yes. But the Meyer draft of the thesis was typed in January 1968, the Model 37 wasn't produced until 1968. Can't rule anything out yet, this is a great suggestion will keep digging.

On the "How Was It Typed" page, Note 6 and beyond are using the same image, and link to an "http://xxxx" placeholder. Different images appear to have been intended (e.g. a Roman Numeral technique is described in the text).

Thanks for this writeup and fascinating analysis - I hope more of the mystery can be solved!

Sorry Sam posted while graphics are being processed they'll be up soon...

https://www.princeton.edu/~hos/mike/transcripts/ritchie.htm:

“MSM: You worked on CTSS there?

Ritchie: Yes I used CTSS because that was what was used during the development of Multics. I didn't work on that - I didn't have anything to do particularly with the development or maintenance of that system. I was just a user.”

⇒ DMR was a user of CTSS at MIT

https://multicians.org/terminals.html:

“The first terminals I used on CTSS were IBM 1050 systems, with Selectric-style golf ball typewriters built into a substantial desk”

The IBM 1050 is from 1963 (https://en.wikipedia.org/wiki/IBM_1050)

⇒ DMR could have used such a terminal.

https://en.wikipedia.org/wiki/TYPSET_and_RUNOFF:

“TYPSET is an early document editor that was used with the 1964-released RUNOFF program, one of the earliest text formatting programs to see significant use”

http://web.mit.edu/Saltzer/www/publications/CC-244.html shows the original RUNOFF didn’t support formulas, superscripts, etc.

Nevertheless, my guess would be he used CTSS to typeset his thesis. Maybe a later version supported this, or he hacked together his own version that did what he needed it to do.

I wonder if the amount of labor required to type corrections is a better explanation than not wanting to pay for binding.

A lot of labor required certainly. But the dmr personal draft had essentially corrected all edits, only six tiny edits still noted to be made.

Ahh, I didn't catch that.

> And now, separately but connectedly, we’re focusing on the question of how Dennis coaxed the typography of his dissertation, the type fonts and positioning of the mathematical notations and layers of sub-and-superscripts, to be as uniform and consistent as they were.

Surely this must be epic-level navel gazing. What am I missing?

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