WOW!!!! $15k DEC PDP-8 CLASSIC MINICOMPUTER SYSTEM DIGITAL PDP8

[Tony Duell]

> > For the pre-1978 (or so) machines, you can pretty much debug down to the
> > chip level. With the right Blue Binders, pretty much every last part is
> > detailed to a silly extent. WAY more detailed than DEC docs.
> 
> I don't see how anything could be more documented than having the complete
> engineering drawings of the whole machine. And that's what you normally

Err, what about ROM dumps, microcode sources, component layouts, PCB track 
patterns, and the like. To be fair, DEC printsets normally included that 
sort of information too...

> got on old DEC machines.
> That's what I have of the PDP-11/70. Full drawings of every curcuit in the
> machine. And then I have all the technical manuals for all subsystems that
> document things in a more text-like manner as well.

You may be clever enough to be able to work everything out from the 
schematics alone, but I find the technical manuals useful too. If you 
want an interesting puzzle, try figuring out the floating point processor 
(at least the 11/45 one, I guess the 11/70 is similar) from the ROM dumps 
and schematics alone. It will take you quite a while I suspect.

I think that's what was meant by 'more detailed'. The DEC docs are in one 
sense complete, but you may have to think quite hard to udnerstand them. 
IBM docs, from what I've heard, explain things really well, but they are 
non-trivial to find.


> 
> But as usual: when in doubt, the drawings are the definitive authority.

Err, the _machine_ is the ultimate authority. There may be ECOs and FCOs 
done to your PCB that are not in the docs.

-tony