Shareware Direct/Shareware Direct.iso/esf/lj3fonts/softfont.doc

Text File | 1991-08-29 | 22KB | 472 lines

  ─────────── The Soft Font Tutorial

                     Copyright 1991 by Elfring Soft Fonts
                             All rights reserved.

                                 INTRODUCTION

  Both laser printers and the DeskJet have become quite popular of late.
  What's the reason for this surge in popularity?  A laser printer is faster
  and much quieter than a dot matrix printer, although they cost a great
  deal more. So why buy one? The majority of these printers are purchased
  because of the wide variety of fonts they support.

  Unfortunately, it isn't until you've owned the printer for awhile that you
  discover just how hard it can be to actually use those fonts.  A fair num-
  ber of people never do learn how to use different fonts with their
  printers.

  The major difficulty with fonts is finding a complete source of informa-
  tion about them.  To use fonts with your laser printer you need: some
  background information on typography, definitions of laser printer ter-
  minology, explanations of fonts and how they are named, and details of the
  printer control language, PCL, used by the HP LaserJet and compatible
  printers.

  There are three different kinds of fonts available for HP LaserJet and
  compatible printers, or the DeskJet.  These are: internal fonts, cartridge
  fonts, and soft fonts.  Once you start printing with these fonts there are
  no real differences between them.  However, getting to the point where you
  can actually print something with these fonts takes some doing. Note that
  DeskJet soft fonts are not compatible with LaserJet fonts.

  There are some disadvantages to soft fonts.  They take up a considerable
  amount of disk space.  They also must be sent to your laser printer before
  they can be used.  Finally, soft fonts are volatile- when you turn off the
  power to your laser printer they vanish.  We feel, however, that the ad-
  vantages listed previously greatly outweigh the disadvantages listed here.
  Hence the need for this tutorial.

  Hopefully, this tutorial will provide you with the information you need to
  take control of your laser printer. Armed with this information you should
  have no trouble selecting and using soft fonts in your printer.

  One final note about the DeskJet printer. The DeskJet is a true line
  printer, not a page printer. While it can handle soft fonts, it requires
  an add on memory cartridge to do so. The DeskJet also has other limita-
  tions, most of which are based on the fact that it is a line printer.







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                                LASER PRINTING

  Before going further into the details of soft fonts it's necessary to ex-
  plain some of the basics of laser printing and its terminology.  If you
  are new to laser printing you need to have a thorough understanding of of
  what a laser printer is and how it works before progressing on to soft
  fonts.  The first thing to do is to define a number of new terms as-
  sociated with laser printers.

  The type of printer that most people are familiar with is a typewriter.
  With a typewriter, you strike a key and a character is printed.  A dot
  matrix printer is very similar in nature to a typewriter.  You instruct it
  to print a string of characters on one line and the dot matrix printer
  prints each one sequentially.  With both typewriters and dot matrix
  printers vertical spacing is usually accomplished by sending a carriage
  return to the printer.

  A laser printer operates on a completely different manner.  Laser printers
  build and print an entire page at a time.  An invisible cursor is used to
  build this page. The cursor tells the laser printer where to put each
  character on the page.  This cursor can be moved automatically by software
  in the laser printer, or it can be addressed with software on your PC.

  To use a laser printer you must send an entire page of text, followed by a
  command to print it.  (If you send more text than will fit on a single
  page, the laser printer will interpret that as a command to print the
  first page.) The interesting thing to note here is that the text that is
  sent to the printer does not have to appear in any specific order.  You
  can print at the bottom of the page, move to the top, and then go back to
  the middle of the page.  As long as you don't go past the bottom of the
  page, or send a "print page" command (Control-L) the laser printer will
  not appear to do anything.  It will simply sit passively and receive your
  text.

  A dot matrix printer normally prints from left to right and from top to
  bottom on a page.  (The more advanced dot matrix printer prints bi-
  directionally, but still must advance from the top to the bottom of a
  page.) A laser printer has no restraints on what direction it prints.  So,
  it then becomes possible to print in several different ways, or orienta-
  tions, on a sheet of paper.  Thus a new set of terms are needed to define
  the orientation of text on a page.

  A page may be printed in either portrait or landscape modes.  In portrait
  mode the paper is positioned just as it would be in a typewriter.  The 8.5
  inch dimension of the paper runs horizontally and the 11 inch dimension of
  the paper runs vertically.  Text appears to run from left to right and
  from top to bottom on the page.

  In landscape mode the paper is positioned as you would place an envelope
  in a typewriter.  The 11 inch dimension of the paper runs horizontally and
  the 8.5 inch dimension of the paper runs vertically.  Text still appears
  to run from left to right and from top to bottom on the page, but the page
  has been rotated 90 degrees.

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  ┌──────────┐  ┌──────────────────────────┐
  │          │  │                          │
  │          │  │       landscape          │
  │ portrait │  │                          │
  │          │  │                          │
  │          │  │          mode            │
  │          │  │                          │
  │   mode   │  └──────────────────────────┘
  │          │
  │          │
  └──────────┘

  Note that the DeskJet Plus and the DeskJet 500 printers can perform
  limited landscape printing using fixed width cartridge of soft fonts. The
  original DeskJet can only perform landscape printing with the addition of
  a special cartridge. None of these printers can print proportionally
  spaced fonts in landscape orientation.


                          LASERJET & DESKJET BASICS

  There are ten different models of LaserJet printers, and three different
  DeskJet printers. Each model has different font handling capabilities and
  comes with a different set of fonts. There are actually three different
  kinds of fonts for either the LaserJet or the DeskJet printer and we
  should define these before going further. Note that DeskJet and LaserJet
  fonts are not interchangeable.

  INTERNAL FONTS are stored inside your laser printer in Read-Only-Memory.
  Each LaserJet model has a different set of internal fonts. Most compatible
  printers offer different sets of internal fonts.

  CARTRIDGE FONTS are Read-Only-Memory fonts that can be added or removed
  from a laser printer. They come in a small box, or cartridge, that can be
  plugged into your printer. Functionally, there is no difference between
  internal and cartridge fonts once the cartridge is plugged into your
  printer.

  SOFT FONT is a term used to describe laser printer fonts that are sold on
  a floppy disk. These fonts must be sent to a laser printer, downloaded,
  before they can be used. They are stored in RAM memory in your laser
  printer. See the following sections for a much more detailed explanation
  of soft fonts.


                             LASERJET RAM MEMORY

  All LaserJet printers require a certain amount of RAM memory in order to
  run. Determining exactly how much memory you will need for your printer
  has never been an easy task. The basic LaserJet II is equipped with 512K
  of RAM, and a LaserJet III has 1 megabyte. Of this amount 295K or 807K,
  respectively, is available for your use. All soft fonts are stored in this


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  memory and all graphic images must also be stored here before they are
  printed.

  A soft font requires about as much storage space in your laser printer as
  it does in a disk file. Actually, there is a complicated formula that
  determines exactly how much memory is used. However, it is easier to ap-
  proximate it this way. A typical 10 to 12 point soft font requires 12K to
  15K bytes of storage. More space is required for fonts that include ex-
  tended character sets. In general, the larger the soft font size the more
  disk space it requires.

  So, if you are not printing any graphic images that 295K of free RAM space
  can hold quite a few soft fonts. The average user does not need any extra
  memory in this case.

  If you plan on printing graphics you will need to set aside memory space
  for them. A LaserJet can print to within 1/4 inch of each border. This
  gives you an 8 x 10.5 inch area, or 84 square inches. At a resolution of
  300 dots per inch you need 7,560,000 bits to hold this image. This is
  equivalent to 945,000 bytes of memory. Adding a 1 megabyte memory board to
  you LaserJet gives you a total of 1,048,576 bytes plus the original 295K,
  or 1,343,576 bytes.

  Thus, by adding a 1 megabyte memory card you can print a full page of
  graphics and still have 398,576 bytes of RAM left for soft font storage.
  This is probably all the memory you will ever need.

  There are a number of PostScript add-on cartridges for the LaserJet line
  of printers. In general, these cartridges need a large amount of addi-
  tional memory before they will work. You usually need to add a minimum of
  2 megabytes of memory to use a PostScript cartridge. You may have to add
  as much as 4 megabytes.


                              DESKJET RAM MEMORY

  All DeskJet and DeskJet Plus printers come equipped with 0K of soft font
  RAM memory. Soft fonts will not work unless you purchase an add-on memory
  cartridge. Each add-on cartridge for the DeskJet gives you 128K of addi-
  tional RAM memory. A DeskJet will accept two of these cartridges giving
  you a maximum of 256K of memory for soft fonts. The DeskJet Plus add-on
  RAM cartridges contain 256K of RAM. This printer also has two slots so a
  Plus can have up to 512K of RAM.

  Note that the only use for RAM memory in either DeskJet printer is for
  soft font storage. Additional memory will not speed the printer up, be
  used as a printer buffer, or let you do landscape printing.

  Determining exactly how much memory you will need for your printer has
  never been an easy task. The DeskJet further complicates this by offering
  algorithmic bolding and half sizing of soft fonts. Thus a 12 point medium
  weight font also works as a 6 point medium weight, a 12 point bold, and a
  6 point bold font!

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  A soft font requires about as much storage space in your DeskJet as it
  does in a disk file. Actually, there is a complicated formula that deter-
  mines exactly how much memory is used. However, it is easier to ap-
  proximate it this way. A typical 10 to 12 point soft font requires 14K to
  17K bytes of storage. More space is required for fonts that include ex-
  tended character sets. In general, the larger the soft font size the more
  disk space it requires. A typical DeskJet soft font is larger than the
  corresponding LaserJet font.

  Since the DeskJet is a line printer, graphic images do not take up any
  memory space since they are not stored in the printer. Graphic printing is
  slower than printing with internal or soft fonts. Adding memory to the
  printer does not effect the print speed at all.


                                  SOFT FONTS

  All LaserJet and DeskJet fonts are bit-mapped. The laser in your laser
  printer marks individual dots to print on a photo-sensitive drum. These
  dots combine to print a letter or draw a line. The LaserJet series of
  printers have a resolution of 300 dots per inch. So everything the printer
  does needs to eventually be turned into a series of dots or bits.

  The DeskJet uses a 50 dot ink jet, with a horizontal resolution of 600
  dots per inch and a vertical resolution of 300 dots per inch. No two
  horizontal dots can ever be printed side by side, so for all practical
  purposes the DeskJet's resolution is the same as the LaserJets.

  Before we can intelligently discuss soft fonts we need to define a few
  typographic terms that will be coming up repeatedly.  These definitions
  will help you understand how bit-mapped fonts are designed and created.
  Three terms in particular are very important.  These are typeface, font,
  and character.

  A TYPEFACE is a particular design or description of what an entire al-
  phabet should look like.  A typeface is independent of the size, height,
  and weight, thickness, of the letters in it.  All right, for the really
  detailed person we'll admit that there may be several typefaces that
  describe a single alphabet on a typesetting machine.  This is not,
  however, usually the case with laser printers.

  A FONT is an implementation of a typeface in a single size and weight.  A
  font is something tangible.  You can buy, rent, or lease a font and use it
  to produce printed documents.  By contrast, a typeface is only a design,
  and thus intangible.  Each font contains a collection of characters that
  follow the design of a particular typeface.

  Finally, a CHARACTER is a single letter or symbol within either a typeface
  or font.  Once again, a character in a font is tangible and can be used to
  print something.  A character in a typeface is simply a design.

  Just what is a soft font?  A soft font is simply an implementation of a
  typeface in a particular size and weight that is saved as a disk file.  A

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  soft font is particular to the laser printer it will be used on, not the
  computer system used to store and transmit it.  Soft fonts designed for
  the HP LaserJet will not work with a Xerox 9700 laser printer, even though
  both printers operate in the same way at the same resolution.  On the
  other hand, a soft font for the HP LaserJet can be stored and used from an
  IBM PC or an Apple Macintosh.

  A soft font is a collection of binary information that describes how to
  print all the characters in a typeface.  The soft font also contains addi-
  tional information about horizontal spacing, underlining, kerning, and
  copyrights.  An HP LaserJet prints at a resolution of 300 dots per inch.
  So each character definition in a soft font must tell your laser printer
  where to put each successive dot in that character.

  So . . .  a soft font is a collection of dot patterns for a laser printer.
  The exact format or organization of this information varies among dif-
  ferent brands of laser printers.  Each point size or weight requires a
  different soft font disk file.

  Note that all fonts for HP laser printers are bit mapped.  The font file
  stores a specific bit value for each dot that will appear on the laser
  printer.  Contrast this to a PostScript printer where outlines are used to
  generate fonts.  (Please remember that even PostScript printers eventually
  turn their font information into a pattern of individual dots.) In
  general, quality 300 dpi bit mapped fonts will look better than those
  produced from outlines, such as PostScript.

  There are some inherent problems with the 300 dot per inch resolution used
  on most laser printers.  This affects the quality of the soft fonts used
  on them.  The 300 dpi resolution is at the limits of human vision.  Almost
  anyone can "see" one three-hundreths of an inch.  When you create a soft
  font from an outline format it must be translated into a bit-mapped for-
  mat.  Some jagged edges will always result from this process.  A hand
  edited font can correct those jagged edges.  Thus, most soft fonts
  produced from outlines do not look as good as a hand edited font.

  PostScript fonts contain "hints" that help avoid some of these problems.
  Outline soft font generators for the LaserJet typically don't have this
  advantage.  However, even the best PostScript font can not compare with a
  hand edited, bit mapped font.  Hand edited fonts custom shape each charac-
  ter so the fonts look as good as possible.  In addition, hand edited fonts
  are typically dithered or feathered.  A dithered font gives much the same
  effect as printing with double the normal resolution.  (The HP Letter
  Gothic font is a good example of what can be done with this process.)


                               USING SOFT FONTS

  Using soft fonts is not as simple as it may seem. You can't just copy a
  font to your printer and print with it in your word processor. It can even
  be difficult to use a font from the MS-DOS command line! Just what is in-
  volved in using a font? This section should answer your general questions
  about using fonts.

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  Before you can print with a soft font there are several things you must
  do. First, that font must be sent to your printer. The process of sending
  a soft font to a printer is called downloading. Downloading a font is
  *not* the same thing as simply copying the font to your printer. The
  printer must be told that this is a soft font and given information on how
  to store it.

  Next, you have to select the font. Just downloading a font to your printer
  does not make it active (an active font is the one you are currently
  printing with). A printer can hold numerous fonts inside its memory, but
  can only print with a single font at one time. To select a font (making a
  font active) in your printer you need to send a special control string to
  the printer telling it how to locate the font.

  Finally, most (but not all) soft fonts are proportionally spaced. This
  means every character in the font occupies a different amount of space
  (has a different width). Your application program needs to have a method
  for dealing with proportionally spaced fonts or you won't get good
  results.

  If you are working from MS-DOS or from within an application program that
  does not know anything about laser printers, the best way to deal with the
  problems mentioned above is to use a simple control program to send the
  font to the printer. ESF's DOWNLOAD or TSR Download programs will send a
  font to your printer and select it. This will let you print in a single
  soft font. You *won't* be able to justify or center text in a proportion-
  ally spaced font with this method.

  If, you want to print multiple soft fonts on a single page or justify text
  in a proportionally spaced font you need an application program that is
  "laser-smart". Laser-smart programs include word processors like WordPer-
  fect, MS Word, MS Works, PC Write, & WordStar. Desktop publishing programs
  like Ventura and PageMaker are also laser-smart. Finally, just about any
  application program that runs under Windows 3.X is laser-smart.

  All laser-smart programs require something called a "printer driver". The
  printer driver tells the application program how to use and control
  specific soft fonts. A printer driver is just a database of information
  about fonts. This database will tell the application program all it needs
  to know to use those fonts.

  Generally, a printer driver has four types of information in it. The
  printer driver will always have a name for the font that you will use to
  select that font. For example a Roman font might have an entry in the
  database like: Roman 12 point. This is the name you will see when you go
  to select this font in your application program.

  A printer driver may have the name and location of the actual soft font
  file. Application programs like WordPerfect and MS Word automatically
  download soft fonts for you. To do this they need the name of the soft
  font file itself, so they can locate and send it to the printer.



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  A printer driver will always have the font selection string needed to ac-
  tivate a font in your printer. In addition, the driver also has to have a
  table that specifies the width of each character in a proportionally
  spaced font, or a width of all characters in a fixed width font.

  Some application programs will make their own printer drivers, based on
  the soft fonts you own. WordStar, PC Write, and Windows are examples of
  these types of application programs. Other programs like WordPerfect, MS
  Word, & MS Works require someone else to build printer drivers for them.
  It is important to remember that *no* laser-smart program can use soft
  fonts without a printer driver. If you are using ESF's LaserJet or DeskJet
  soft font packages with WordPerfect or MS Word/Works you *must* install
  our matching printer drivers before you can use these soft fonts. If you
  use something like WordStar, PC Write, or Windows, you *must* go through
  the steps necessary to build a printer driver, yourself, for each of those
  products.

  For more information on soft fonts contact: Elfring Soft Fonts, PO Box 61,
  Wasco, IL  60183  USA.  Voice: 708-377-3520  Fax: [phone]



































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