On Fri, Nov 10, 2017 at 1:32 PM, Noel Chiappa <jnc@mercury.lcs.mit.edu> wrote:
    > From: Will Senn

    > what was it like to sit down and learn unix V7 on a PDP? ... What
    > resources did you consult in your early days

Well, I started by reading through the UPM (the 8-section thing, with commands
in I, system calls in II, etc). I also read a lot of Unix documentation which
came as larger documents (e.g the Unix Intro, C Tutorial and spec, etc).
​Exactly -- BTW the printed ​binders that Larry mentions were a few years away.   Brian Redman of Whippany (the 'ber' of honey-dan-ber UUCP), got them printed in the early 1980s.


 

I should point out that back then, this was a feasible task.
​Agreed...​

 
Most man pages
were really _a_ page, and often a short one. By the end of my time on the PWB1
system, there were about 300 commands in /bin (which includes sections II, VI
and VIII), but a good chunk (I'd say probably 50 or more) were ones we'd
written. So there were not that many to start with (section II was maybe 3/4"
of paper), and you could read the UPM in a couple of hours. (I read through it
more than once; you'd get more retained, mentally, on each pass.)
​Yup, I'm not sure how many times I read through UPM, but it was a few times.

What was amazing to me, was compared to say TOPS or even RSTS it seemed like I could actually understand the whole thing.​


 

There were no Unix people at all in the group at MIT which I joined, so I
couldn't ask around; there were a bunch in another group on the floor below,
although I didn't use them much - mostly it was RTFM.
​It was very much a learn as you go.  Ted Kowalski would show up a little later and start to explain/argue about things that I had confused./wrong.
But my first attempts were pretty lonely.


 

Mailing lists? Books? Fuhgeddaboutit!
​:-)​

 

My next step in learning the kernel was to start reading the sources.
​ditto...​

 
(I
​ ​
didn't have access to Lyons.)
​I got access to Lyons after Ted showed up.   I was so impressed ;-)​

 
I did an 'cref' of the entire system, and
transferred the results to a large piece of paper, so I could see who was
calling who in the kernel.
​Great mind thinks a like.   Although I had to transfer some of the stuff to the PDP-10​ I had 'tools' there and was still learning the UNIX ones.
I did not understand grep at first. I remember the moment of enlightenment the first time, I understood what I could do with it.
Seriously, find and grep were the two new tools that changed the way I started to think about computers.  I had nothing like them on the 10's.

 


    > What were your goto resources? More than just man and the sources?

That's all there was!

I should point out that reading the sources to command 'x' taught you more
than just how 'x' worked - you saw how people interacted with the kernel, what
it could do, etc, etc.
​Yeah, same here.  I spent a lot of time staring at Kernel and Application code.​