Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!sdd.hp.com!hp-pcd!hp-vcd!neff From: neff@hp-vcd.HP.COM (Dave Neff) Newsgroups: comp.sys.mac.misc Subject: Re: comments on the Laserwriter LS vs. GCC PLP II ?? Message-ID: <1040005@hp-vcd.HP.COM> Date: 19 Mar 91 19:26:37 GMT References: <27E53199.10548@orion.oac.uci.edu> Organization: Hewlett Packard, Vancouver, WA Lines: 50 >Seems that the LS is a kind of bust, speed-wise. Has anyone tried the PLP II? >It's priced about the same, and also comes with scalabe fonts. Also being a >QuickDraw printer, it should be able to do TrueType no problem. Anybody have >any thoughts? I'm afraid the general fact you will find is that QuickDraw laser printers are not going to particularly fast. The problem is you have to image the entire page on the Mac first, then transfer the entire page to the printer, and the finally the "4 page per minute" laser engine can move a peice of paper through the printer. Hence once all the imaging and data transfer is done, then there is another 15 seconds before you see the output. A printer like the HP DeskWriter is not a page printer, and it can start printing as soon as the first data comes in (the imaging on the Mac still must be done first). So in many cases the DeskWriter is actually done printing a page when the QuickDraw laser printers just start moving the paper through the engine. The times I have seen for the GCC printers are comparable to those I have seen for the LS which are also in the same ballpark as the DeskWriter. One other fact to remember with the GCC printers is that "list price == street price", which is not true with the LS or the DeskWriter. The PLP uses the SCSI connection and images the entire page on the MAC then sends sends the image down "real time", which precludes the use of spoolers (if I am not mistaken). Neither the GCC nor the LS work on AppleTalk. I do have a question/concern about the LaserWriter LS. A press release I read said the printer only has 1/2 meg of RAM and uses data compression to store an entire page in 1/2 meg. This is all very well and good and the DeskWriter uses data compression as well to reduce the IO transfer time. However, a page of 300 DPI data requires 1 meg to print in the worst case and there are always some kinds of images that don't compress well at all. I know there are documents that the DeskWriter driver can only compress to 600K or so per page. How can the LaserWriter LS guarantee a 2:1 or greater data compression ratio, and what does it do if it doesn't get this ratio? My belief would be that there are images that the LaserWriter LS cannot print with its 1/2 meg of RAM. Would anyone "in the know" care to comment? I believe the GCC PLPs have a similar problem on low memory Macs, if the image does not compress well and there is not a full meg free on the Mac there will be problems in printing -- but at least you can add memory to your Mac, and the extra memory on the Mac is useful for other things. There doesn't seem to be a way to add memory to the LS (at least Apple isn't pushing it). There quite possibly is a way to add memory, but since most people will never see a problem Apple doesn't want to confuse the issue. Dave Neff neff@hpvcfs1.HP.COM Disclaimer: These comments are the personal observations of a mere printer firmware engineer, and do not necessarly reflect HP policy.