Scanning question (Is destruction of old tech docs a moral crime?)

Dave Wade dave.g4ugm at
Wed Jul 24 03:45:48 CDT 2019

> -----Original Message-----
> From: cctalk <cctalk-bounces at> On Behalf Of Paul Koning via
> cctalk
> Sent: 24 July 2019 01:30
> To: Jon Elson <elson at>; General Discussion: On-Topic and
> Off-Topic Posts <cctalk at>
> Subject: Re: Scanning question (Is destruction of old tech docs a moral
> crime?)
> > On Jul 21, 2019, at 12:16 PM, Jon Elson via cctalk
<cctalk at>
> wrote:
> >
> > On 07/21/2019 05:16 AM, Joseph S. Barrera III via cctalk wrote:
> >> What dpi qualifies as not "crappy"? 300dpi? 400? 600?
> >>
> >>
> > Most of the text of these documents don't need super high resolution.
> But, some contain hand-drawn schematics where an 11 x 17 original has been
> shrunk to 8.5 x 11" and hand-written signal labels and part types are VERY
> small.  These need to be scanned at high resolution, with several retries
> while adjusting the image threshold to make things readable.
> Another example that might call for higher than normal resolution is
> text, where subtle distinctions need to be visible.  An example of this
can be
> found in the scans in the Knuth archive of the THE operating system
> Those are line printer listings printed with a typical medium-worn ribbon
> that's bad enough.  But the printer is upper case only printing mixed-case
> source material.  That was handled in that OS by overprinting upper case
> letters with periods.  In a clean original printout that's easy enough to
> but the scans seem to be about 300 dpi and with that the overprints are
> often not easy to see.  Since the source text is case sensitive this can
be a
> problem...
> 	paul

I think you folks are forgetting that often the choice is scan and have a
record, or just put it in for pulping.
Storing paper is not easy and not cheap. I deeply regret binning my Wireless
World magazines from the 1970's or 1980's but there is no way I could keep
When I offer documents on here or other platforms frequently no one is
prepared to take them (I am in the UK).
The same goes for some physical objects such as printers. 
If you want it to be a crime then start a crowd sourcing fund to save it....


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