Looks excellent -- friendly edit -- ditroff had nothing to do with vcat/vpr/vtroff. Tom Ferrin wrote the original at UCSF in the mid/late 70s -- the reasons was the the CAT typesetter was expensive and actually kinda nasty run. Many of us had plotters in those days and Tom's hack was a welcomed addition to the tool set. instead of: leading some developers to contrive translators for C/A/T-formatted documents to other devices. An example was vtroff for Versatec and Benson-Varian plotters. I offer: In mid/late 70s, Tom Ferrin a graphics researcher at UCSF using the font set released in the late 1960s, from Alan Hershey [ https://en.wikipedia.org/wiki/Hershey_fonts], wrote a program to simulate the C/A/T typesetter allowing the output of the original troff program to be 'plotted'. This program originally called vcat for virtual cat typesetter, was first distributed as part of an early USENIX distribution tape, but was eventually re-released in 3BSD and later BSD distributions as the UCB vpr(1) command and associated wrapper that call it was created called vtroff. On Wed, Jan 12, 2022 at 1:07 PM G. Branden Robinson < g.branden.robinson@gmail.com> wrote: > Hi, Dan, > > At 2022-01-12T11:33:35-0500, Dan Cross wrote: > > I have some questions about the earlier history. > > I've been collecting a detailed narrative history not just of the *roff > _programs_ but also of the development on the language in the roff(7) > manual page. Below I'll share a current chunk of it that is planned for > the next release (groff 1.23). It has been heavily revised since > groff 1.22.4. Many of my revisions have been motivated by accounts from > this list, from the "history of man pages" (more of a history of troff) > at manpages.bsd.lv, and the minnie TUHS archive. > > > As I understand it, in the beginning there was RUNOFF, which I believe > > originated on CTSS? The CTSS sources contain a RUNOFF program that's > > made up of ~1100 lines of MAD and ~1300 lines of assembler. > > This is a detail I hadn't encountered before; instead I've read claims > that distorted it into being a solely high-level language project. > > > There is certainly a RUNOFF in Multics, written in BCPL (there's a > > small "outer module transfer vector" program in ALM). > > As I understand it, _this_ RUNOFF is undisputedly Doug McIlroy's. > > > This is where it gets muddy for me; I understand this was roughly > > ported to unix as `roff` by Ken and that at this point, > > It is hard to find an account of this period that _isn't_ muddy. Claims > from Murray Hill luminaries suggest that V0 and V1 Unix roffs were the > collective work of Thompson, Ritchie, Ossanna, a fourth person who > contributed the hyphenation algorithm (does someone have the name?), and > McIlroy, because in Ritchie's words[1], this roff was "transliterated" > from Doug's BCPL codebase. > > > formatting was fairly primitive: suitable for hardcopy terminals and > > line printers, and could do things like center lines and so forth, but > > nothing fancy (https://www.cs.dartmouth.edu/~doug/reader.pdf). > > Yes. My contributions to groff's roff(7) page attempt to shed more > light on this sort of thing. Sadly, at crucial periods sources and even > documentation are missing. For example, there is an nroff entry in the > Unix V2 manual table of contents, but no man page is present. In other > early editions the reader is asked to see Ossanna for documentation, and > it seems the corresponding artifacts might be lost to time. > > > Ossanna then took over and greatly expanded the capabilities of > > `roff`, adding macros and traps and making it Turing-complete; this > > was `nroff`, which grew to become `troff` once the C/A/T typesetter > > was acquired. > > Yes. > > Here's what I have, though it looks better typeset[2]. Corrections from > witnesses are warmly welcomed. > > Name > roff - concepts and history of roff typesetting > > Description > The term roff describes a family of document formatting systems > known by names like troff, nroff, ditroff, and groff. A roff > system consists of an extensible text formatting language and a > set of programs for printing and converting to other text > formats. Unix-like operating systems often distribute a roff > system as a core package. > > [snip] > > History > Computer-driven document formatting dates back to the 1960s. The > roff system itself is intimately connected with the Unix > operating system, but its roots go back to the earlier operating > systems CTSS and Multics. > > The predecessor--RUNOFF > roff's ancestor RUNOFF was written in the MAD language by Jerry > Saltzer to prepare his Ph.D. thesis using the Compatible Time > Sharing System (CTSS), a project of the Massachusetts Institute > of Technology (MIT). The program is generally referred to in > full capitals, both to distinguish it from its many descendants, > and because bits were expensive in those days; five- and six-bit > character encodings were still in widespread usage, and mixed- > case alphabetics seen as a luxury. RUNOFF introduced a syntax of > inlining formatting directives amid document text, by beginning a > line with a period (an unlikely occurrence in human-readable > material) followed by a "control word". Control words with > obvious meaning like ".line length n" were supported as well as > an abbreviation system; the latter came to overwhelm the former > in popular usage and later derivatives of the program. A sample > of control words from a RUNOFF manual of December 1966 web.mit.edu/Saltzer/www/publications/ctss/AH.9.01.html> was > documented as follows (with the parameter notation slightly > altered). The abbreviations will be familiar to roff veterans. > > Abbreviation Control word > .ad .adjust > .bp .begin page > .br .break > .ce .center > .in .indent n > .ll .line length n > .nf .nofill > .pl .paper length n > .sp .space [n] > > In 1965, MIT's Project MAC teamed with Bell Telephone > Laboratories and General Electric (GE) to inaugurate the Multics > project. After a few years, Bell > Labs discontinued its participation in Multics, famously > prompting the development of Unix. Meanwhile, Saltzer's RUNOFF > proved influential, seeing many ports and derivations elsewhere. > > In 1969, Doug McIlroy wrote one such reimplementation of RUNOFF > in the BCPL language for a GE 645 running GECOS at the Bell Labs > location in Murray Hill, New Jersey. In its manual, the control > commands were termed "requests", their two-letter names were > canonical, and the control character was configurable with a .cc > request. Other familiar requests emerged at this time; no-adjust > (.na), need (.ne), page offset (.po), tab configuration (.ta, > though it worked differently), temporary indent (.ti), character > translation (.tr), and automatic underlining (.ul; on RUNOFF you > had to backspace and underscore in the input yourself). .fi to > enable filling of output lines got the name it retains to this > day. > > Unix and roff > roff was one of the first Unix programs. McIlroy's runoff was, > in Dennis Ritchie's term, "transliterated" from BCPL to DEC PDP-7 > assembly language for the fledgling Unix operating system. It > saw its name shortened to roff (perhaps under the influence of > Ken Thompson), while adding support for automatic hyphenation > with .hc and .hy requests; a generalization of line spacing > control with the .ls request; and what later roffs would call > diversions, with "footnote" requests. This roff indirectly > funded operating systems research at Murray Hill, for it was used > to prepare patent applications for AT&T to the U.S. government. > This arrangement enabled the group to acquire a PDP-11; roff > promptly proved equal to the task of typesetting the first > edition of the manual for what would later become known as "Unix > Version 1", dated November 1971. > > Output from all of the foregoing programs was limited to line > printers and paper terminals such the IBM 2471 (based on the > Selectric line of typewriters) and the Teletype Corporation Model > 37. Proportionally-spaced type was unknown. > > New roff and Typesetter roff > The first years of Unix were spent in rapid evolution. The > practicalities of preparing standardized documents like patent > applications (and Unix manual pages), combined with McIlroy's > enthusiasm for macro languages, perhaps created an irresistible > pressure to make roff extensible. Joe Ossanna's nroff, literally > a "new roff", was the outlet for this pressure. By the time of > Unix Version 3 (February 1973)--and still in PDP-11 assembly > language--it sported a swath of features now considered essential > to roff systems: definition of macros (.de), diversion of text > thence (.di), and removal thereof (.rm); trap planting (.wh; > "when") and relocation (.ch; "change"); conditional processing > (.if); and environments (.ev). Incremental improvements included > assignment of the next page number (.pn); no-space mode (.ns) and > restoration of vertical spacing (.rs); the saving (.sv) and > output (.os) of vertical space; specification of replacement > characters for tabs (.tc) and leaders (.lc); configuration of the > no-break control character (.c2); shorthand to disable automatic > hyphenation (.nh); a condensation of what were formerly six > different requests for configuration of page "titles" (headers > and footers) into one (.tl) with a length controlled separately > from the line length (.lt); automatic line numbering (.nm); > interactive input (.rd), which necessitated buffer-flushing > (.fl), and was made convenient with early program cessation > (.ex); source file inclusion in its modern form (.so; though > RUNOFF had an ".append" control word for a similar purpose) and > early advance to the next file argument (.nx); ignorable content > (.ig); and programmable abort (.ab). > > Third Edition Unix also brought the pipe(2) system call, the > explosive growth of a componentized system based around it, and a > "filter model" that remains perceptible today. Equally > importantly, the Bell Labs site in Murray Hill acquired a Graphic > Systems C/A/T phototypesetter, and with it came the necessity of > expanding the capabilities of a roff system to cope with > proportionally-spaced type, multiple type sizes, and a variety of > fonts. Ossanna wrote a parallel implementation of nroff for the > C/A/T, dubbing it troff (for "typesetter roff"). Unfortunately, > surviving documentation does not illustrate what requests were > implemented at this time for C/A/T support; the troff(1) man page > in Fourth Edition Unix (November 1973) does not feature a request > list, unlike nroff(1). Apart from typesetter-driven features, > Unix Version 4 roffs added string definitions (.ds); made the > escape character configurable (.ec); and enabled the user to > write diagnostics to the standard error stream (.tm). Around > 1974, empowered with multiple type sizes, italics, and a symbol > font specially commissioned by Bell Labs from Graphic Systems, > Brian Kernighan and Lorinda Cherry implemented eqn for > typesetting mathematics. In the same year, for Fifth Edition > Unix, Ossanna combined and reimplemented the two roffs in C, > using preprocessor conditions of that language to generate both > from a single source tree. > > Ossanna documented the syntax of the input language to the nroff > and troff programs in the "Troff User's Manual", first published > in 1976, with further revisions as late as 1992 by Kernighan. > (The original version was entitled "Nroff/Troff User's Manual", > which may partially explain why roff practitioners have tended to > refer to it by its AT&T document identifier, "CSTR #54".) Its > final revision serves as the de facto specification of AT&T > troff, and all subsequent implementors of roff systems have done > so in its shadow. > > A small and simple set of roff macros was first used for the > manual pages of Unix Version 4 and persisted for two further > releases, but the first macro package to be formally described > and installed was ms by Lesk in Version 6. He also wrote a > manual, "Typing Documents on the Unix System", describing ms and > basic nroff/troff usage, updating it as the package accrued > features. Sixth Edition additionally saw the debut of the tbl > preprocessor for formatting tables, also by Lesk. > > For Unix Version 7 (January 1979), McIlroy designed, implemented, > and documented the man macro package, introducing most of the > macros described in groff_man(7) today, and edited volume 1 of > the Version 7 manual using it. Documents composed using ms > featured in volume 2, edited by Kernighan. > > Ossanna had passed away unexpectedly in 1977, and after the > release of Version 7, with the C/A/T typesetter becoming > supplanted by alternative devices such as the Mergenthaler > Linotron 202, Kernighan undertook a revision and rewrite of troff > to generalize its design. To implement this revised > architecture, he developed the font and device description file > formats and the device-independent output format that remain in > use today. He described these novelties in the article "A > Typesetter-independent TROFF", last revised in 1982, and like the > troff manual itself, it is widely known by a shorthand, "CSTR > #97". > > Kernighan's innovations prepared troff well for the introduction > of the Adobe PostScript language in 1982 and a vibrant market in > laser printers with built-in interpreters for it. An output > driver for PostScript, dpost, was swiftly developed. However, > due to AT&T software licensing practices, Ossanna's troff, with > its tight coupling to the capabilities of the C/A/T, remained in > parallel distribution with device-independent troff throughout > the 1980s, leading some developers to contrive translators for > C/A/T-formatted documents to other devices. An example was > vtroff for Versatec and Benson-Varian plotters. Today, however, > all actively maintained troffs follow Kernighan's device- > independent design. > > Regards, > Branden > > [1] "The Evolution of the Unix Time-Sharing System", Ritchie, 1984 > [2] Formatted with: > groff -man -P-c -Tascii -rLL=72n -rHY=0 -dAD=l build/man/roff.7 > (The `AD` string is new to groff 1.23 man(7).) >