Al Kossow <aek at bitsavers.org> wrote:
(talking about Tony Duell's circuit diagrams)
After examining the results of his work, I would
suggest that your
friend should learn how to CORRECTLY scan hand-drawn line art.
I will not make the mistake of buying later versions of his disc
What's wrong with them? Do you object to them being hand drawn?
I think he objects to the file format (jpeg?) used. I am pretty sure it's
not the best choice _but_ I didn't choose it.
I have used the 9915A and 9825A schematics when
repairing my 9915B and
my 9825A (ongoing), and they are clear, correct, and readable [1].
Look, Tony is doing a service to the community, *and* he is not making
money out of this, so bitching about his insistence on doing things his
way is counter productive both for you and for the rest of us.
Thank you. I am glad somebody finds this work useful.
[1] in fact the 9915 schematics are much more
readable than the HP
supplied diagrams for the HP-85 (which has many similarities to the
I have seen _many_ examples of scanned manuals on the web where the
schematics are unreadable. I am not sure if this is due to the originals
being a poor-qulaity copy, or due to the scanning process, or what. In
some cases there are bits missing when an A3 page is scanned as 2 A4
pages (If I am _copying_ such a page, I always check, and if necessary
make a 3rd copy containing the overlap.
9915). In fact any time there was disagreement between
the HP prints
and Tony's, the hardware agreed with Tony's drawings.
None-the-less, I would be very suprised if there were no more errors in
these diagrams (I have found some already, I do of course correct them in
the next version of the disk). If you come across something that
disagrees with the hardware, I would appreciate a (polite) comment.
Either I have made a mistake (very likely!) or there's another version of
the board that I've not seen.
-tony