For Apple Macintosh Computer and HP Deskwriter Printers.
1) Requires HP Deskwriter Serial or Appletalk drivers.
2) Requires a copy of Apple's ResEdit (2.1 and 2.1.1 are the latest).
3) Requires that you care if you have high quality greyscales in your printer output.
4) Includes this file, Greyscales Made Easy, HP Greyscale PAT# and a demo file named Greyscales.PICT.
Begin
Fixing the Deskwriter's greyscale performance 100% for Canvas™ and improving it for MacDraw II, Superpaint, MacDraft, etc.
Q) What's broken?
A) Nothing is really broken. Greyscales are merely black and white dot patterns arranged to approximate a grey shade. On your computer screen, these dots are arrayed in a “clunky” 72 dots per inch (DPI) pattern. Your Deskwriter, however, is capable of an elegant 300 DPI pattern. The 72 DPI greyscale needs to be translated to a 300 DPI greyscale.
Q) I thought I already had 300 DPI?
A) You do! Your fonts and all your drawing objects are sent at 300 DPI. But patterns (greyscales included) are transmitted to the printer by the application at 72 DPI to the Deskwriter because it is a QuickDraw device and that is how things are done for patterns.
Q) Then there is nothing I can really do about it, is there?
A) But yes! Hewlett Packard (HP), in their infinite wisdom, put into each of their Deskwriter drivers (Versions 2.2 and the latest 3.1) two conversion tables in a resource called “PAT#”. One table contains a list of 72 DPI greyscales and the other a list of 300 DPI greyscales. There are 21 conversions in the version 2.2 table and 15 in the version 3.1 table.
Q) So?
A) So if a 72 DPI greyscale matches one of the 15 patterns in the first table, the Deskwriter immediately substitutes the 300 DPI greyscale pattern from the second table. Clever, no?
Q) Then I already have 300 DPI greyscales covered, right?
A) Well, yes and no. Not every drawing program uses the same pattern to approximate the same grey shade. HP designed their Deskwriter 3.1 tables to make every drawing program deliver the same greyshade pattern. To make this work, however, the results come out at only 75 DPI which isn't much of an improvement. The older Deskwriter 2.2 had a couple of 300 DPI patterns and the rest were 75 DPI.
Q) Is that why I sometimes got a really smooth grey in one shade but a spotty grey in another shade with Version 2.2?
A) You got it!
Q) So how did you fix this?
A) I changed the PAT# table. For the 72 DPI side, I installed an extensive 65 pattern list (including white and black) using the patterns recognized by Canvas™. For the 300 DPI side I designed a matching 65 pattern conversion.
Q) Why Canvas™?
A) Canvas™ has the most extensive greyscale for a program which supports QuickDraw so wholeheartedly. The other big hitters rely on postscript for their greyscales. Many of the greys from the other drawing programs will match too. If they don't, you just get the 75 DPI version instead.
Q) How can you substitute 65 patterns when there were only 15 to begin with? Won't the rest be ignored?
A) The HP programmers wrote their code to never assume a fixed number in the table. They always accomodate any size table. This is real programming professionalism.
Q) Was this a easy as it sounds?
A) No! The inkjet printers make an ink dot that spreads out so that a black dot is fatter than a white dot. The 300 DPI table had to be carefully “thinned out” to take this into account.
Q) Let's cut to the bottom line! How do I fix my Deskwriter?
A) You don't touch your printer, just the software driver in the System Folder. Follow the following instructions.
1) Locate the Deskwriter driver (either version) in your System Folder (Extensions Folder inside System Folder for System 7). Make a copy of it (Command-D) and name it differently from the original. I use “Deskwriter Greyscale” or “DW 3.1 Greyscale”. Whatever!
2) The required resources are in the a file I gave you called “HP Greyscale PAT#”. Launch ResEdit and open this file. A small window will reveal 2 resources: “PAT#” and “vers”. Select both (Command-A) and copy (Command-C). Close the window. Keep ResEdit open.
3) Open the Deskwriter copy you made (don't work on an original, please!). When the window opens, (lots of resources will show) just Paste (Command-V). Answer “Yes” (and only Yes) to the dialog that askes if you wish the replace the old resources. Close the window. Answer “Yes” to the dialog asking if you want to save the changes.
4) Quit ResEdit. You are done!
5) You may use the driver immediately without restarting. After you restart your computer, however, the Get Info box of that driver will now include “Greyscale by Ray DiBugnara” so you can always tell a converted driver.
6) If you select Chooser from the Apple Menu, you will now see both Deskwriter drivers: the original and the greyscale version. For version 3.1, print spooling works for both drivers (after you turn it on for the new driver). You can compare drawings printed with both drivers…the stock version and the 300 DPI greyscale version.
7) I have included a demo file for you to open and print. It is in the PICT format so any drawing program you have can open it and print it. I think you will be pleasantly surprised.
Q) How much is this gonna cost me?
A) Zip. I hereby release this to public domain. Such a deal! Just keep all the files together if you give away a copy.
Hints: Keep your Deskwriter clean. The shiny chrome rod that the print head slides on can get dirty causing the head to shudder ever so slightly. This can cause slight irregularities in an otherwise smooth grey pattern. I use a few drops of CRC spray lubricant (hardware or automotive stores) on a cotton pad to clean the rod, moving the head gently from side to side (when the printer is off, please!). Never spray into the printer or onto the head. The coating must be so thin that you can't see it.
Q) Hey, how about some WD-40?
A) You again! I do not recommend it. It leaves a residue and will eventually dry and cause even more sticking. A silicone lubricant may substitute, however, but I can't recommend a brand that I trust.
