[TUHS] Does anybody recall how the TU10 bootstrap code actually operates?

Noel Chiappa jnc at mercury.lcs.mit.edu
Thu Dec 24 04:02:48 AEST 2015

    > Thank you for responding so carefully.

The devil is in the details...

    > I have been reading the PDP-11/40 handbook, much too much :)

I'm not sure that's possible! :-)

Yes, yes, I know, the architecture is deader than a doornail for serious use,
but I liken it to sailing vessels: nobody uses them for serious cargo haul any
more, but they are still much beloved (and for good reasons, IMO).

The PDP-11 is an incredibly elegant architecture, perhaps the best ever (IMO),
which remains one of the very best examples ever of how to get 30 pounds into
the proverbial ten-pount sack - like early UNIX (more below).

    > this is really elegant code. The guys who thought this up were amazing.

Nah, it's just a clever hack (small-scale).  What is really, almost
un-approachably, brilliant about early UNIX is the amount of functionality
they got into such a small machine.

It's hard to really appreciate, now, the impact UNIX had when it first
appeared on the scene: just as it's impossible for people who didn't
themselves actually experience the pre-Internet world to _really_ appreciate
what it was like (even turning off all one's computers for a day only
approximates it). I think only people who lived with prior 'small computer
OS's' could really grasp what a giant leap it was, compared to what came

I remember first being shown it in circa 1975 or so, and just being utterly
blown away: the ability to trivially add arbitrary commands, I/O redirection,
invisibly mountable sections of the directory tree - the list just goes on and
on. Heck, it was better than all but a few 'big machine' OS's!

    > Thanks again for your help.

Eh, de nada.


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