I didn't deal with DEC mauals, nor did I often deal with Heath/Zenith stuff. In
fact, Heath and Zenith hadn't "merged" by the timeframe I'm remembering.
Nevertheless, I can remember more than one case wherein I had board revisions a,
b, and c of a given board, and the same error, on schematic revisions a, b, and
c appeared. That convinced me the mfg's were trying to "protect" something.
It's true, the Tandy doc's that I saw were about as good as any of the time,
though the underlying designs were often about as poor as any of the time.
Dick
----- Original Message -----
From: "Tony Duell" <ard_at_p850ug1.demon.co.uk>
To: <classiccmp_at_classiccmp.org>
Sent: Tuesday, April 03, 2001 11:49 AM
Subject: Re: D connector tirade (was: Re: Age-old ethernet equipment)
> >
> > >At least with S100 stuff (say) you often had schematics. And pinouts of
> > >all the connectors. And data sheets for the chips. Some manufacturers
> > >were better than others, of course, but few supplied only manuals that
> > >were as bad as the so-called documentation you get with PC products these
> > >days.
> >
> > Both of my kit systems (Heath/Zenith Z-100 and SWTPc 6809)
> > have excellent manuals that go into the timing, schematics, and chip
> > datasheets. Tandy used to have available seperately some excellent
> > tech manuals on their various systems. I've got a number of them,
>
> IMHO the best manuals at that time (not considering the price) were the
> ones from DEC. The PDP8/e maintenance manuals in particular are almost
> tutorials on computer operation. The PDP11/45 manuals aren't bad either
> (things like a cycle-by-cycle description of the microcode). But DEC
> manuals were _very_ expensive (although probably worth it)
>
> Other companies had excellent manuals as well -- one that sticks in my
> memory is a Philips service manual for one of their P800 series of
> minicomputers that contains an entire section on the operation of the
> SMPSU, complete with current and voltage waveforms for the chopper
> circuit. Just what you need when you have PSU problems.
>
> But the best _value_ manuals were Tandy IMHO. They included all the
> essential information (Schematics, ROM calls, that sort of thing), and
> were cheap. I can remember paying 99p (!) for the CoCo 1 technical
> manual. Now, admittedly that was in a half-price sale, but even at
> \pounds 1.99 it was still excellent value. I also remember getting my
> Model 100, and ordering the techref for it. It cost something like
> \pounds 3.99. Again, it has all the information I needed in it (I/O
> connector pinouts, schematic, data on all the main chips, and so on).
>
> To be fair, there have been some other excellent manuals for micros.
> Heathkit/Zenith ones are great (or at least the ones for my Z90 are).
> Although I don't much care for the machine, the Apple ][ Reference manual
> is not bad. And even though Apple no longer supplied such a manual with
> the //e, it was at least available as an extra (I found it in a London
> computer bookshop a few years back amongst the Mac manuals. Needless to
> say I bought it).
>
> It's hard to think of a micro from before the days of PC clones where
> such information was not available.
>
> Now, alas, it's hard to think of a machine where it is.
>
> > including the nearly 400page service manual for the Model 2000.
> > Osborne had a pretty serious set of tech manuals for their products
> > as well, the ones for the Executive spanning 5 volumes, including the
> > source for it's ROM monitor and BIOS. Atari did a similar manual for
> > the 400/800.
>
> Ever seen the HP71 IDS? That's 3 volumes on software, 1 volume on
> hardware, 1 volume on HPIL for a _calculator_. You get ROM source,
> schematics, assembly language, timing diagrams, ROM calls, and lots more
> information.
>
>
> > With most of today's systems, you're lucky to get any kind of
> > manual at all. It's just as likely to be a flyer of just a few pages
> > as it is to be a PDF file on the system CD. Certainly nothing that
> > goes too in-depth into the actual hardware.
>
> I wouldn't object to a .pdf on the CD (even though I particularly dislike
> that file format) if it included some useful information. After all, if I
> bought a modern machine, it would probably have a graphical display, so I
> would be able to read a .pdf. And in any case I am sure I could find
> somebody who would read it and print it out for me for a suitable fee.
>
> Problem is, such manuals do not contain useful information...
>
> -tony
>
>
Received on Tue Apr 03 2001 - 19:38:50 BST