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From: David Chappell <David.Chappell@mail.trincoll.edu> Date: Fri, 26 Jan 2001 12:10:15 -0500 Subject: Re: Antwort: Re: PPR: ppr newbie Alain.Lachapelle@Heimannsystems.Com wrote: > > In the last week I have tried several printing packages for Linux with the > same goal: to have error reports from PostScript printers. Granted, many > packages have lots of options and it is not always easy to evaluate in a > short period of time. I find that even if the PPR package also has a lot > of options (always better to have anyhow) it manages to have a well-defined > path for introduction. It is not possible to say that of every printing > pacakge for Linux. As the author of PPR, I may not be the best one to judge if PPR has achieved its goals. Goal number one was to make communication with the printers robust and to make it easy to see what is wrong when communications problem occur and to make it easy to see what the system is doing when it appears to be stuck. I believe that this goal has been largely achieved. It is worth noting that version 1.41 took a significant step forward in achieving the second part of this goal. The second goal has been to make the system easy to configure. I would say this is about 50% done. I would like to believe that the "ppad" commands are fairly simple and straight-forward, at least when compared to lpr and lp. However, this process still requires a certain amount of technical understanding of printing protocols and the like. Also, the sheer number of options is bewindering. In answer to this, I have attempted to make the defaults reasonable so that only a few commands are actually necessary to set up each printer. The WWW interface, with its Add Printer wizard is another step forward. Future plans include automatic detection of printer make and model (in order to choose the correct PPD file) and installed optional equipment. The single biggest problem with PPR is that many PostScript printer drivers generate PostScript which has syntax and semantic errors in the Document Structuring Convention comments. There are three approaches to this problem. One is to get the authors to fix the offending programs. This is very slow and time consuming. The other is to construct little Perl scripts to fix the PostScript that these programs produce. PPR has a system called "editps" which automatically selects the correct script and runs the input through it. The third approach is to put PPR in "transparent" mode. Unfortunately, this means that any PPR feature which involves manipulating the print stream is disabled. Also, transparent mode was origionally intended only as a testing tool. Since it was never intended for production use, switching it on sometimes had effects that people didn't expect. I believe that in version 1.41 most of these problems have been ironed out. The second problem with PPR is that the tutorial is out-of-date. The reference manual is almost completely up-to-date in its description of the features, but it doesn't really tell people when and why they should be using them. > > Trying various options I haven't find, though, how to undo a Tray mount nor > a PPD assignment. I end up erasing the files and restart over. Is there a > way? With ppad mount I have tried "Tray2 none" and "Tray2 invalid" to no > avail. > The tray mount complaint has already been addressed in version 1.42 which I will release next week. Version 1.42 will also fix support for Internet Explorer in the WWW interface. As a holdover from very early versions of PPR, it is actually legal to define a printer with no PPD file. However, the ppad command provides no way to do this. If you create a print queue without defining a PPD file, it will use a default PPD file, which I think is "Apple LaserWriter II". If you are determined, delete the line from the printer's definition file in /etc/ppr/printers. But, you should not want to do this. > > I have noticed that there's an entry in the "Selecting a PPD File" of the > documentation that reads like: > > `HP DeskJet 550C PPD Ghostscript'' > > A non-PostScript inkjet printer combined with Ghostscript. > > I would like to use PPR at home with my HP PSC 500 All-in-One inkjet > printer (parallel interface) which is not a PS printer. The above entry > leads to believe that it is possible to do so. What are the pros and cons > of using PPR with a non-PS printer? The Ghostscript support works with very few problems. The only problem I can think of is that sometimes when you cancel a job that is printing, the printer is left in graphics mode and needs to be manually reset before it will print correctly. In order to set up a printer with Ghostscript, you need to choose two things. One is the correct Ghostscript driver. Some knowledge of Ghostscript helps here. The other is a PPD file which is "close enough". I have provided 4 PPD files which describe typical Ghoscript/printer combinations. These include a 300 DPI laser printer, a 24 pin dot matrix printer, a 300 DPI ink-jet printer, and a color ink-jet printer. In the near future I intend to make printing with Ghostscript more robust and provide appropriate options menus in the Add Printer wizard to make it easier to select the correct Ghostscript driver.