> > Since PDF didn't exist in 1981, the document is either a scan or the > result of a recent *roff run on ancient source. >
It's most definitely a scan. Magnifying the pages reveals dust, surface details (grain and creases), and shadow falloff around the holes and edges. Each page is also titled at slight angles, suggesting manual scanning of individual pages. it's an impressive testimonial to the longevity and stability of troff. > Absolutely! On Tue, 7 Jun 2022 at 00:09, Douglas McIlroy <douglas.mcil...@dartmouth.edu> wrote: > > > https://www.tuhs.org/Archive/Documentation/Manuals/Unix_4.0/Volume_1/C.1.2_NROFF_TROFF_Users_Manual.pdf > > Since PDF didn't exist in 1981, the document is either a scan or the > result of a recent *roff run on ancient source. If it was made from > source, it's an impressive testimonial to the longevity and stability > of troff. Most probably it's a scan, in which case we owe many thanks > to the public-spirited person who digitized this trove. Was it you, > Arnold? > > Doug > >
