TEX is a new document compiler under development by D. E. Knuth here at the
lab. An experimental version is obtainable by typing "r tex" to the monitor;
this experimental version assumes to some extent that the very next thing
you type is "\input <file><CR>" (note that it's \ not /). This makes
TEX look at <file>.TEX on your area, or failing that to look at <file>.TEX
on system area [1,3]. Your output will be on <file>.XGP and it can be
spooled with "xs <file>/head/ntn=33"; omit "/head" if you don't want the
fine print atop each page telling you the date and time of spooling.
This experimental version of TEX has thirteen font files preloaded, so
if you want other fonts besides the ones declared in file basic.TEX[1,3] they
should be assigned font codes other than "@adfgjlmquxz?".

About a dozen copies of the first draft writeup are floating around the lab,
and a dozen more at Polya Hall. There's no on-line or line-printer version,
but you might be able to figure out how to read manual.xgp[tex,dek]. The
SAIL program contains extensive documentation, it's not merely "commented code";
see file TEXSYS.SAI[tex,dek] and the files it references.