David_Anthony_Guevara@cup.portal.com (09/11/89)
Have any of you seen/experienced the HP DeskWriter performance when it is hooked to a Mac Plus? The store demos I have seen were all done with a Mac II. I'm impressed with the printer, but since I have a Mac Plus, I am concerned that I will be waiting forever for my printouts to finish. Please respond to me via e-mail. I'm sure the net doesn't need any more traffic. I'll summarize to the net if there is enough interest. Thanks! Dave
barry@primerd.prime.com (09/12/89)
A DeskWriter on a Mac SE is about 1/2 the speed (very roughly) of the
DeskWriter on a Mac SE/30. The performance with a Mac Plus ought to be
very similar to that with the Mac SE. Printing to a DeskWriter is
normally CP limited on a SE, so you can expect it to be CP limited with
the Plus.
------------------------------------------------------------------------
Barry Wolman | barry@s66.prime.com
Principal Technical Consultant | 492 Old Connecticut Path
Prime Computer | Framingham, MA 01701
| 508/626-1700, ext. 4187
------------------------------------------------------------------------
Nothing in this posting reflects an official position of Prime Computer.stevem@hpvcfs1.HP.COM (Steve Miller) (09/20/89)
>Could someone briefly summarize exactly what the protocol is between >a MAC and a DeskWriter. [more questions omitted] The Mac and DeskWriter communicate at 57.6 Kbaud and use a special compression mode to make sure that the printer isn't I/O bound. The DeskWriter is not a general PCL device and doesn't implement the full PCL command set. On Mac II type machines, the printer is primarily mechanism limited and on Mac+/SE type machines the printer is usually CPU bound. Steven Miller Vancouver Division Hewlett Packard
fjo@cbnewsc.ATT.COM (frank.j.owen) (09/21/89)
From article <780053@hpvcfs1.HP.COM>, by stevem@hpvcfs1.HP.COM (Steve Miller): > > On Mac II type machines, the printer is primarily mechanism > limited and on Mac+/SE type machines the printer is usually CPU > bound. > I have MacPlus and a DeskJET printer. (NOT DeskJET plus) This bit of info makes me feel a little better about my purchase choice. (I bought the thing long before the introduction of the DeskJet plua or Writer ) Apparently, you don't get the full benefit of the faster printer until you put it on a II-class machine. What I'd really like to know is why HP doesn't release their printer driver for use with the DeskJet? It seems to me that all they'd have to do is change the speed to 19.2 KBaud, and they'd be in business. I am presently using the HPDJ public domain driver, and am not particuliarly satisfied with the results. If HP doesn't come out with a driver, I'll probably wait for system 7.0, and hope that a sys 7.0 compatible DeskJet driver will appear. -- Frank Owen 312-982-2182 AT&T Bell Laboratories 5555 Touhy Ave., Skokie, IL 60077 PATH: ...!att!ihc!fjo
neff@hpvcfs1.HP.COM (Dave Neff) (09/22/89)
>What I'd really like to know is why HP doesn't release their printer >driver for use with the DeskJet? It seems to me that all they'd have >to do is change the speed to 19.2 KBaud, and they'd be in business. I >am presently using the HPDJ public domain driver, and am not particuliarly >satisfied with the results. If HP doesn't come out with a driver, I'll probably >wait for system 7.0, and hope that a sys 7.0 compatible DeskJet driver >will appear. Although this isn't the entire answer, the DeskWriter uses a new 2 dimensional data compression machine called "mode 3" graphics. This mode did not exist when the DeskJet and DeskJet+ was designed. The Mac DeskWriter driver makes heavy use of this graphics compression mode and without it would in many cases be IO limitted even at 57K baud, let alone 19.2K baud. There are many other reasons, such as support, customer satisfaction, and so forth. By the way, the new HP LaserJet IIP does (I'm pretty sure) have support for "mode 3" graphics. Its fastest baud rate is 19.2K. When we tried out our Mac DeskWriter driver at this baud rate to a LaserJet II (not a IIP) which had special code supporting mode 3 graphics it was SLOWER THAN A DESKWRITER. And a LaserJet IIP is slower than a II. I can't go into all the reasons for this, but the speed difference is more than just the difference between 19.2K and 57K bauds. Steve Miller has the actual time differences, maybe he could post them. There actually is a "trick" that will allow a DeskWriter to run at 19.2 baud (unsupported, undocumented, not guaranteed to remain, and I wont tell anyway), and the DeskWriter at 19.2K baud is faster than a LaserJet II at 19.2K baud using our DeskWriter driver. People who assume laser printers must be faster/better/more reliable than technologies such as inkjet are often basing their belief on this sort of "myth" that laser printers are the ultimate in printing technologies. Every technology (thinking of the big three -- laser, inkjet, impact) has advantages and disadvantages compared to the other. Dave Neff neff@hpvcfs1.HP.COM
stevem@hpvcfs1.HP.COM (Steve Miller) (09/22/89)
>> >> On Mac II type machines, the printer is primarily mechanism >> limited and on Mac+/SE type machines the printer is usually CPU >> bound. >> > I have MacPlus and a DeskJET printer. (NOT DeskJET plus) This bit of >info makes me feel a little better about my purchase choice. (I bought the >thing long before the introduction of the DeskJet plua or Writer ) >Apparently, you don't get the full benefit of the faster printer until >you put it on a II-class machine. Even though a DeskWriter is generally CPU bound on a MacPlus, it is still faster than the DeskJet or DeskJet Plus solutions for the Mac. The only solution that comes close to DeskWriter's performance is Orange Micro's new Grappler LX product on a DeskJet Plus. The only other case is when the built in fonts of the DeskJet are used (ugh). Steven Miller Vancouver Division Hewlett Packard
harry@ngc.UUCP (Harry Saal) (09/23/89)
Thanks to HP for illuminating some of the reasons the DeskWriter is so swift. I was frankly quite disappointing by the marketing hype surrounding the DeskJet vs. DeskJet Plus, because it talked about speed advantages "in certain cases" but really didn't address "average" documents, nor spell out what cases had been optimized. I ended up having these two models side by side, running what I felt were "typical" usages, and the Plus showed around a 5% advantage (perhaps stop watch error?). Could we learn more about when Mode 3 compression is a winner? Does it help with documents that are typical of rich output from Word, Draw or Paint?
neff@hpvcfs1.HP.COM (Dave Neff) (09/26/89)
> Thanks to HP for illuminating some of the reasons the DeskWriter is > so swift. I was frankly quite disappointing by the marketing hype > surrounding the DeskJet vs. DeskJet Plus, because it talked about > speed advantages "in certain cases" but really didn't address "average" > documents, nor spell out what cases had been optimized. I ended up > having these two models side by side, running what I felt were "typical" > usages, and the Plus showed around a 5% advantage (perhaps stop watch > error?). The DeskJet+ is mainly faster when the centronics port is used and when dealing with graphics output (compressed or otherwise) and font downloads. If you are using a serial port and/or printing mainly text the DeskJet+ will not be much faster. Most of the third party DeskJet drivers for the Mac are CPU and/or IO limitted so the DeskJet+ does not give much of a speed advantage. The DeskJet+ also picks and moves paper twice as fast but the ink cartridge still moves at the same speed. This makes the printer seem much faster (watching a DeskJet load paper after using a DeskJet+ is painful) but the paper pick/move time is really a small part of the overall print time (that was maybe the 5% you saw). For centronics graphics only output the DeskJet+ is really 5 times faster than a DeskJet. For text its a bit faster. Depending on your mix of text to graphics, what IO is being used, and how fast your CPU can generate the images, the numbers can be anywhere between no faster to 5 times faster comparing a DeskJet to DeskJet+. If you are using a serial port at 19.2K baud and your application/driver uses the mode 2 compression for full page graphics, and can generate the images fast enough, the DeskJet+ will be about 2 to 3 times faster than a DeskJet. Obviously it is impossible to say the DeskJet+ is N times faster than a DeskJet when there are so many variables that affect the result (CPU, graphics, text, downloads, compression modes, and IO). Comparing the DeskWriter to the other Mac printers is easier since the main variable is CPU and memory configuration. Everything else is pretty much fixed. > Could we learn more about when Mode 3 compression is a winner? Does it help > with documents that are typical of rich output from Word, Draw or Paint? I don't know to what extent we are allowed to talk about mode 3 compression. We have applied for a patent on the technique so it has been made public to the extent that the patent application requires. It basically helps with everything except heavily dithered scanned images. It is similar to compression modes used by FAX machines but enhanced. It has been added to the official HP Printer Control Language specification. I'll try to find out if we can talk about more details. Dave Neff neff@hpvcfs1.HP.COM
yost@esquire.UUCP (David A. Yost) (09/26/89)
In article <780057@hpvcfs1.HP.COM> neff@hpvcfs1.HP.COM (Dave Neff) writes: >The DeskJet+ is mainly faster when the centronics port is used and when >dealing with graphics output (compressed or otherwise) and font downloads. > ... For centronics >graphics only output the DeskJet+ is really 5 times faster than a DeskJet. Why not make a SCSI->Centronics adaptor as an official supported HP product for Mac users? --dave yost
neff@hpvcfs1.HP.COM (Dave Neff) (09/28/89)
>In article <780057@hpvcfs1.HP.COM> neff@hpvcfs1.HP.COM (Dave Neff) writes: >>The DeskJet+ is mainly faster when the centronics port is used and when >>dealing with graphics output (compressed or otherwise) and font downloads. >> ... For centronics >>graphics only output the DeskJet+ is really 5 times faster than a DeskJet. >Why not make a SCSI->Centronics adaptor >as an official supported HP product >for Mac users? > > --dave yost Because the DeskWriter is the official supported HP printer for Mac users. Are we going around in circles yet :-). Really, the issue is one of support, user satisfaction, and so forth. Prior to the DeskWriter there was no "HP blessed" solution to using DeskJets with the Mac. The DeskWriter is specifically designed and optimized for use with the Mac. We don't want to confuse the issue by providing alternatives. Of course third party alternatives (chooser drivers with various high speed serial or SCSI to centronics converter) are always possible, but its up to the third party to support the DeskJets in that configuration, not HP. It wouldn't be too hard to convert the DeskWriter driver to work with the DeskJet+ using 19.2K baud and mode 2 graphics. This would give about a 1/2 page per minute printer (compared to the 1 page per minute of DeskWriter). Certainly some sort of hardware converter could put performance closer to the DeskWriter (the DeskWriter would still be a bit faster due to bi-directional graphics and other enhancements). We'd just have to support it. Call our support line at 208-323-2551 and tell them you want such a supported driver. If enough people call maybe the right people would respond, you never know. Dave Neff neff@hpvcfs1.HP.COM
yost@esquire.UUCP (David A. Yost) (09/29/89)
In article <780063@hpvcfs1.HP.COM> neff@hpvcfs1.HP.COM (Dave Neff) writes: >Prior to the DeskWriter there was no "HP blessed" solution to using >DeskJets with the Mac. The DeskWriter is specifically designed and >optimized for use with the Mac. > >Of course third party alternatives (chooser drivers with various >high speed serial or SCSI to centronics converter) are always possible, > >Certainly some sort of hardware converter could put >performance closer to the DeskWriter (the DeskWriter would still be a >bit faster due to bi-directional graphics and other enhancements). Now I'm totally confused. Are you saying that if HP were to offer a DeskWriter option that used a SCSI connection to the printer, it would not yield improved speed over the present DeskWriter configuration? BTW, what is the DeskJet interface? LocalTalk? Serial at some high baudrate? Is the DeskJet driver an in-house development, or did HP acquire it from Insight or somewhere else outside? --dave yost
neff@hpvcfs1.HP.COM (Dave Neff) (10/03/89)
In article <780063@hpvcfs1.HP.COM> neff@hpvcfs1.HP.COM (Dave Neff) writes: >Prior to the DeskWriter there was no "HP blessed" solution to using >DeskJets with the Mac. The DeskWriter is specifically designed and >optimized for use with the Mac. > >Of course third party alternatives (chooser drivers with various >high speed serial or SCSI to centronics converter) are always possible, > >Certainly some sort of hardware converter could put >performance closer to the DeskWriter (the DeskWriter would still be a >bit faster due to bi-directional graphics and other enhancements). >>Now I'm totally confused. Are you saying that if >>HP were to offer a DeskWriter option that used a >>SCSI connection to the printer, it would not yield >>improved speed over the present DeskWriter configuration? No you aren't confused. Adding a faster interface to the DeskWriter would not improve performance. Why? The DeskWriter can only mechanically pick up paper and move the print head over the paper at about a 1 page per minute rate. This is the rate the DeskWriter runs on a Mac II for most cases. The DeskWriter is not IO limittted, it is mechanism limitted, so faster IO would make no difference. >>BTW, what is the DeskJet interface? >>LocalTalk? Serial at some high baudrate? >>Is the DeskJet driver an in-house development, >>or did HP acquire it from Insight or somewhere >>else outside? The DeskWriter has a 57K baud serial interface. The DeskJet/DeskJet+ has a 19.2K baud serial and a parallel interface. On the DeskJet+ the parallel interface can run much faster than 19.2K baud. That is, the DeskJet+ will be IO limitted at 19.2K baud but will be mechanism limitted using the parallel port (assuming the application/driver can generate graphics at a 1 page per minute rate or better). Hence a hardware converter for the Mac could boost performance for a DeskJet+ (IO limitted) but would make no difference for a DeskWriter (mechanism or CPU limitted). The DeskWriter also has mode 3 graphics which results in much greater graphics compression than the mode 2 support in the DeskJet+. This also helps the DeskWriter to not be IO limitted at 57K baud. The DeskWriter driver was written in house with help from Palomar Software and using the Compugraphics Intellifont outlines and filling/ scaling algorithms. Dave Neff neff@hpvcfs1.HP.COM