eaeu137@orion.oac.uci.edu (Andrew Theodore Laurence) (03/19/91)
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? --Andrew Laurence eaeu137@orion.oac.uci.edu
neff@hp-vcd.HP.COM (Dave Neff) (03/20/91)
>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.
ewright@convex.com (Edward V. Wright) (03/22/91)
In article <1040005@hp-vcd.HP.COM> neff@hp-vcd.HP.COM (Dave Neff) writes: >There doesn't seem to be a way to add memory to the LS (at least Apple >isn't pushing it). That's not true. This is covered in the owner's manual. Just take the LS in to any Apple dealer and he can upgrade the memory to 1M by installing a couple of SIMMs.
pascal@CAM.ORG (Pascal Gosselin) (03/22/91)
neff@hp-vcd.HP.COM (Dave Neff) writes: >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 Both the LaserWriter SC and LaserWriter LS can start imaging a new page while a page is still printing, so the DeskWriter might only be faster if the document is <= 1 page. >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 Not true. GCC has dealers and they can sell at whatever price they want. I know, we are a GCC dealer. >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. Apple does recognize that SOME pages cannot be compressed into 512K, which is why there is a service upgrade that brings the printer up to a full meg of RAM, enabling the LaserWriter LS to print any pattern. In such a case (and you only have 512K), the LS driver will display an error message indicating that the printer does not have enough memory to print the entire page and will then proceed to print out whatever it had generated so far (I haven't tested this, but this is what Apple claims). >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. -- +----------------------------------------------------------------------------+ | Pascal Gosselin | Internet: P.Gosselin@CAM.ORG Applelink: CDA0585 | | Gest-Mac Inc. Apple VAR | Voice (514) 767-4444 Fax (514) 767-7337 | +----------------------------------------------------------------------------+