A while back UCLA posted the STATA 1 Reference Manual. I've gone through the files, made them searchable, added a few key links and bookmarks, and combined them into a single PDF file. If anybody wants it, the link is

https://drive.google.com/file/d/1YIE...ew?usp=sharing

Incidentally, people are occasionally chastised for writing STATA instead of Stata. Actually, people who do so are actually just being old-fashioned, because it was spelled STATA in the STATA 1 Reference Manual.

Just skimming through it, you can see how way back in 1984 Stata was already building a framework that was much more logical and consistent than what programs like SPSS had (and still has). I think that has contributed a lot to Stata's success.