lori@kodak.UUCP (Lori Perreault) (05/23/89)
I'm hoping that some of you out there will have some ideas for speeding up the print of graphics to a laserwriter. Presently we have 3550's and 4500's connected to a laserwriter II, when we do a "screendump" we must wait approx- imately 20 minutes for each print out. Not only is this a long time for a print, but it ties up the printer for all other needs. Imagine when I need 20 different graphics...... Is anyone familiar with any products on the market which will speed this up? I appreciate any insight. Thanks!
dbfunk@ICAEN.UIOWA.EDU (David B Funk) (05/23/89)
WRT posting <1893@kodak.UUCP>: > I'm hoping that some of you out there will have some ideas for speeding up > the print of graphics to a laserwriter. Presently we have 3550's and 4500's > connected to a laserwriter II, when we do a "screendump" we must wait approx- > imately 20 minutes for each print out. Not only is this a long time for a > print, but it ties up the printer for all other needs. Imagine when I need > 20 different graphics...... I'm assuming that: 1) when you say "screendump" you're talking about an Apollo GPR or GMF bitmap, such as that produced by "cpscr" or the DM "XI" command 2) when you say "laserwriter" you're talking about an Apple LaserWriter or some equivalent PostScript speaking laser printer. The problem is that LaserWriters & PostScript, though great for page description based jobs, are terrible for binary bitmap printing. PostScript is an ASCII based language so the binary data of the bitmap must be read in by the print server, converted to an ASCII encoded form, transfered to the printer as 7-bit ASCII characters, decoded back into a bitmap, doing any needed scaling in the process, and only then put on paper. I think that most of that 20 minutes is in doing the computing needed to implement this process. The best answer to this problem is to get tools oriented to doing the job. The HP LaserJet series of printers are designed to do bitmap printing based upon a binary raster scan bitmap data format. This is almost an exact match to the format of Apollo bitmap graphics files. We have several HP LaserJet+ printers driven by a localy written print server driver. We have found that the print time is almost exactly equal to the time it takes to transfer the binary data via the serial port. IE take the size of the bitmap file, in bytes, and divide it by the serial port data rate, in characters (baud/10) to get the approx. print time. EG to print a 1280 X 1024 monochrome bitmap ("cpscr" on a 1280bw machine) at 150 BPI with the printer connected via a serial line at 19200 baud takes about 90 seconds. If you want dithering for grey-scale printing or interpetation of color bitmaps then you're going to add lots of overhead to this process. But if you only want single bit plane monochrome output, then the LaserJet is unbeatable. It also costs less than the LaserWriter. :=) Note that, currently, the LaserJet doesn't give you PostScript, so it won't work as an output device for PDL based applications like InterLeaf. There are other laser printers that have both LaserJet emulation and PostScript, that should give you the best of both worlds. I haven't tried one of these and don't know how well they work. There is a LaserJet driver available in the ADUS library. I will give a copy of mine to anybody who wants one. Currently I only have a sr9.7 version, I'm not done with the sr10 conversion yet. Dave Funk
krowitz@RICHTER.MIT.EDU (David Krowitz) (05/23/89)
Dave, Interestingly enough, You can run your SR9.7 print servers under SR10 as is. You just have to set the the /sys/print directory and the links to it like you normally do under Sr9 and use the "-pre10" option when using /com/prf on SR10 machines. When you give the command "prf -pre10" on an SR10 machine, it bypasses the print manager and creates an SR9 style print queue entry which your current print servers are looking for. == Dave Krowitz
markw@hpsal2.HP.COM (Mark Williams) (05/24/89)
While I am delighted that the HP Laserjet is such a great match to Apollo bitmaps, I realize that the lack of Postscript on the Laserjet has been a problem. Voila! Enter the HP Laserjet IID, which has built-in Postscript capability and keeps all the other features we all like in the other models. Also prints double-sided. Try it, you'll like it.