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Re: reprints of old AI memos (was Re: boxing all integers)

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Lars Brinkhoff writes:
> Kragen Javier Sitaker wrote:
>> Is the BDF conversion lossy?  Glancing at the Python, it doesn’t appear
>> to be thresholding grayscale or anything like that.
> It's not my script, and I haven't checked.  But I would guess it's a 1:1
> pixel conversion.  What grayscale are you talking about?

I now understand you are referring to the final PDF, which indeed is in
grayscale.  But that is not due to the fonts, which are plain bi-level
both in the original PDP-10 data and converted to BDF.  The BDF fonts
are not involved making the PDF anyway.

The "putting dots on paper" process making the PDF happens in the PDP-11
emulator running the XGP code.  The output is written to an oversampled
floating-point array representing the amount of ink across the page.
This is downsampled to 200 DPI with a plain box filter, which is how the
grayscales happen.

The number 200 is only an approximation.  It's something like the
average resolution across a horizontal line.  But actually the
resolution varies across that line; I forget whether it's higher or
lower at the edges.  And the vertical resolution is closer to 192 DPI,
which makes the text taller.  I suppose an argument could be made that
the emulator is an "ideal XGP" which is somewhat better than the
original machine.

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boxing all integers (was Re: Resources to learn common lisp?) Kragen Javier Sitaker <kragen@canonical.org> - 2026-08-29 17:52 -0300
  Re: boxing all integers (was Re: Resources to learn common lisp?) Lars Brinkhoff <lars.spam@nocrew.org> - 2026-08-30 06:43 +0000
    Re: reprints of old AI memos (was Re: boxing all integers)f Kragen Javier Sitaker <kragen@canonical.org> - 2026-08-30 13:11 -0300
      Re: reprints of old AI memos (was Re: boxing all integers)f Lars Brinkhoff <lars.spam@nocrew.org> - 2026-08-31 05:14 +0000
        Re: reprints of old AI memos (was Re: boxing all integers) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-08-31 06:54 +0000
        Re: reprints of old AI memos (was Re: boxing all integers)f Kragen Javier Sitaker <kragen@canonical.org> - 2026-08-31 13:43 -0300
          Re: reprints of old AI memos (was Re: boxing all integers)f Kragen Javier Sitaker <kragen@canonical.org> - 2026-08-31 13:56 -0300
            Re: reprints of old AI memos (was Re: boxing all integers)f Paul Rubin <no.email@nospam.invalid> - 2026-08-31 13:34 -0700
              Re: reprints of old AI memos (was Re: boxing all integers)f Rich Alderson <news@alderson.users.panix.com> - 2026-08-31 18:12 -0400
                Re: reprints of old AI memos (was Re: boxing all integers)f scott@slp53.sl.home (Scott Lurndal) - 2026-09-01 15:12 +0000
            Re: reprints of old AI memos (was Re: boxing all integers)f Lars Brinkhoff <lars.spam@nocrew.org> - 2026-09-01 05:59 +0000
              Re: reprints of old AI memos (was Re: boxing all integers)f Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-02 15:23 -0300
          Re: reprints of old AI memos (was Re: boxing all integers) Lars Brinkhoff <lars.spam@nocrew.org> - 2026-09-01 05:45 +0000
            Re: reprints of old AI memos (was Re: boxing all integers) Lars Brinkhoff <lars.spam@nocrew.org> - 2026-09-01 07:07 +0000
            Re: reprints of old AI memos (was Re: boxing all integers) Rich Alderson <news@alderson.users.panix.com> - 2026-09-01 17:36 -0400
              the history of the Hershey fonts (was Re: reprints of old AI memos) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-02 15:55 -0300
                Re: the history of the Hershey fonts (was Re: reprints of old AI memos) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-02 21:31 +0000
                Re: the history of the Hershey fonts (was Re: reprints of old AI memos) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-03 09:59 -0300
            Re: reprints of old AI memos (was Re: boxing all integers) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-02 16:35 -0300
              Re: reprints of old AI memos (was Re: boxing all integers) Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-09-02 21:50 +0000
                PDF file compactness (was Re: reprints of old AI memos) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-03 12:06 -0300
              Re: reprints of old AI memos (was Re: boxing all integers) Lars Brinkhoff <lars.spam@nocrew.org> - 2026-09-03 05:42 +0000
                Re: reprints of old AI memos (was Re: boxing all integers) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-03 12:50 -0300
            origin of XGP fonts (was Re: reprints of old AI memos) Kragen Javier Sitaker <kragen@canonical.org> - 2026-09-28 10:44 -0300
              Re: origin of XGP fonts (was Re: reprints of old AI memos) Peter Flass <Peter@Iron-Spring.com> - 2026-09-28 07:33 -0700
                Re: origin of XGP fonts (was Re: reprints of old AI memos) Johann 'Myrkraverk' Oskarsson <johann@myrkraverk.invalid> - 2026-09-28 22:53 +0800
      Re: reprints of old AI memos (was Re: boxing all integers)f Lars Brinkhoff <lars.spam@nocrew.org> - 2026-09-06 08:40 +0000

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