On Fri 13 Jul 2018 at 13:52:23 (+0100), Brian wrote: > On Thu 12 Jul 2018 at 16:22:33 -0500, David Wright wrote: > > > On Wed 11 Jul 2018 at 16:34:48 (+0000), Curt wrote: > > > On 2018-07-11, Brian <a...@cityscape.co.uk> wrote: > > > > > > > > The interest being expressed is one in printing a PDF directly to a > > > > printer, so CUPS isn't (or needn't be) be involved. No conversion to > > > > or from PostScript (which is no longer being developed) is undertaken. > > > > Any delays would lie in transporting the file to the printer and what > > > > takes place on it. > > > > > > > > > > That exists, it seems (pdf interpreter in the firmware of the printer). > > > > > > https://okiprinting-en-gb.custhelp.com/app/answers/detail/a_id/581/~/pdf-direct-printing > > > > > > Some of the higher-end (at least) HPs apparently have a feature called HP > > > Direct PDF, which > > > appears to be exactly what it says. > > > > > > Maybe that isn't the question (if there's a question) and everybody knew > > > that pdf > > > printers existed but me. > > > > I've know that PDF printers exist, but have never had the money to buy > > one. Those I'm familiar with are washing-machine-sized and are found > > in libraries and offices. Their critical property (particularly on > > account of their location) is that they can print PDFs from a USB > > stick. > > That's a printer which prints PDFs, not a PDF printer. Ok, it could have > the firmware to print directly to PDF but there is insufficient data to > form an opinion. Without the firmware, the PDF on the USB stick will be > converted to something the printer understands - just as CUPS does.
I have a PDF printing system here. Give me a PDF and I can print it. By that I mean that a computer file that starts and finishes with, say, %PDF-1.2 and %%EOF will end up as an appropriate collection of marks on the paper. But my printer is not a PDF printer. Given a data stream of the same description arriving at one of its input ports, it would not be capable of the same result. A PDF printer would. The mention of a USB stick acts as a shibboleth, making sure there's no conversion taking place outside the printer itself. (A PostScript printer would likewise be able to handle a document enclosed by, say, %!PS-Adobe-3.0 and %%EOF.) > > Our aio printer can print from a stick, but only jpegs, not PDFs. > > As one would expect, printing from a computer therefore requires > > CUPS to push it through a driver¹, and the quality of printing (and > > even the area of the paper used) depends on that driver. > > > > OTOH our printer can scan to a stick, writing a PDF file. That > > requires no driver/computer/sane system. Of course, AIUI, the PDF > > is really just a container for some sort of image content, but > > that's fine as I can apply all the PDF tools (pdfjam, pdftk etc) > > at a document level, rather than jpg by jpg. > > A useful facility; just the thing for removing confidential documents > from a secure environment. :) Well, that doesn't differ very much from a scanner talking to sane on a computer with a USB port in terms of security. But in terms of usefulness, scanning to a USB stick is part of the civic infrastructure of any town. (Fortunately, its marginal cost is virtually zero.) > > So I'm disappointed that the Brother is only an alleged PS printer and > > not a PDF one. > > > > > To tell the truth (and why the hell not at this late date), I was fuzzy > > > up until recently (quite recently, like ten minutes ago) as to what a > > > postscript printer was precisely. Now I know. Seems obvious now. > > > > I was a PS printer user (with no responsibility for how it was driven) > > for many years, starting in 1985. Driving them was a black art: > > interfacing with appletalk, dealing with limited memory, font handling > > and so on. As printer and comms speeds, memory and PS specs increased, > > and PDF printers arrived, most of those complications have > > disappeared, at least for us users. > > > > So, as far as printing from my computer is concerned, a printer that > > only handles PS, and not PDFs, wouldn't be a great step forward. > > > > ¹ rasteriser, whatever. > > Less expensive printers that handle printing PDFs directly are becoming > more common. The Brother HL-L5000D can be had for under 120 GBP: > > http://support.brother.com/g/b/spec.aspx?c=eu_ot&lang=en&prod=hll5000d_us_eu_as That's certainly a satisfactory list of emulations there as it includes PDF. Some of them, like IBM Proprinter XL and Epson FX-850 bring back memories of writing drivers for a bunch of mainly dot-matrix printers in the '80s and '90s. Cheers, David.
