On Wed, 6 Jul 2005 William Donzelli <aw288 at osfn.org> wrote:
To: "General Discussion: On-Topic and Off-Topic
Posts"
<cctalk at classiccmp.org>
Message-ID: <Pine.SUN.4.20.0507062219110.19631-100000 at osfn.org>
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Even where IBM cards of that era used
'commodity' components, they were
usually completely house-marked and impossible for a mere mortal to
figure out. This goes all the way down to resistor networks and
resistors/capacitors (except those few that have color-code bands.)
Unless you get the cross reference...
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
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.
But as usual: when in doubt, the drawings are the definitive authority.
Johnny
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at update.uu.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol