On Sunday 13 September 2015, Gene Heskett wrote:
> On Sunday 13 September 2015 06:17:04 Lisi Reisz wrote:
> > On Saturday 12 September 2015 23:28:46 Gene Heskett wrote:
> > > The filter is primarily because in order for the current gs to print
> > > it, there needs to be a translation between a pdf and a ps.
> >
> > Thanks, Gene.  But my question was why??  Why does it have to be
> > translated?
> >
> > Lisi
>
> GS, aka Ghostscript, back in v5 days, had a very good pdf level 2
> renderer.  It was also hell to compile, I did it twice on a big box
> amiga in the '90's.
>
> Somewhere along the line, someone decided the best way to handle the
> bloat was to excise the pdf stuffs from ghostscript and let it
> concentrate on postscript only.  Hence the need for a pipeing filter,
> called pdftops, to translate and expand the pdf into postscript that gs
> understands.
>
> Both are random access file formats, but pdf uses a second lookup depth I
> haven't fully understood, and that must be translated and piped into gs
> as pure postscript.
>
> FWIW, a properly done Level 3 pdf is the ultimate file compression when
> applied to a large document.  This particular file that generates a 740
> page, with lots of graphics, manual is just north of 121 megabytes.  By
> the time pdftops has unpacked it and sent it to gs, it is still quite
> conmpressed, but the translation makes about 546 megabytes that gets
> sent over the pipe to gs.  The resultant data that flows down the cat5
> (or the slower USB if your printer doesn't have a network presence) to
> the printer is probably in excess of 5 terrabytes.
>
> In the old days, I did not have a duplex capable printer, so I would
> command gs to make a file per page, then wrote an arexx script to send
> all odd pages to the printer, then when that was done, turn the pile
> over and then then send all the even numbered pages.  But that filled up
> a 1Gb seagate drive , so had to be cleaned up if I wanted to do it to a
> different big pdf, else it was out of disk.
>
> But I had to make the arexx script check the file size, and if it was
> under 100 bytes, it was nothing but the setup and teardown for the page,
> so rather than send that file to the printer, which if it was sitting at
> TOF, ignored a formfeed, so I sent it a line feed to get it off of TOF
> position, then the formfeed, which would eject the desired blank page,
> keeping the printout in the order desired, even for a 500+ page
> document.  Without that, the binding ditch was fubar.  Thats the space
> at the left edge of an odd page, or the right edge of an even page where
> a wider margin is used so the 3 hole punch misses the text.
>
> I had an extended, and fruitless discussion with the gs maintainer at the
> time who couldn't conceive of a printer ignoring a formfeed if it was
> sitting at the top of the page already, but every Merican printer I ever
> had did ignore it including a couple Brother Daisy wheelers. Writing the
> arexx script was less hassle than trying to convince that person that he
> needed to add one linefeed byte in front of the formfeed.  Sigh...
>
> Your daily dose of ancient ghsotscript trivia. ;-)
>
> Cheers Lisi, Gene Heskett

That explains a lot. Thank you for the history lesson.

Kate