GEMini Atari/GEMini_Atari_CD-ROM_Walnut_Creek_December_1993.iso/zip/gnu/gs252b.lzh/GS252B/README.ST

Text File | 1993-07-30 | 13KB | 288 lines

GS 2.52, REVISION 0 FOR THE ATARI ST:

GHOSTSCRIPT OVERVIEW:    11/92

Ghostscript is the GNU project's postscript language interpreter.  It
can be used to convert postscript files into formats suitable for
non-postscript printers, or to display postscript files on the screen.
The last Atari version was 2.41 revision 1.

GS 2.52 was compiled with gcc 2.2.2 and mintlibs PL 24. Using the
mintlibs has apparently eliminated the odd incompatiblilty that
programs compiled with the ordinary libs have exhibited in the
past.

Version 2.52 added as standard some functionality which was already
available in the ST version of 2.41.  Because of this, the manner in
which the user specifies the size of a "band-printing" buffer has
changed.  Another major feature is the ability to select the page size
from the command line.  These changes make gemGS 1.2 somewhat
incompatible with GS 2.52.  You should use gemGS 1.3 with 2.52,
especially if you want to use the new page-sizing feature.

Here is a brief overview of the remaining atari-specific features:

1.) The stvdi screen device supports 2, 4, and 8 bit color, although I
have not yet had enough feedback to determine whether 8-bit color
works properly on any hardware.  The vdi routines are used to
determine the screen parameters and to copy to the screen, so graphics
should work on lots of different screen devices.  Unfortunately, the
color driver is very slow, since I implemented in the
most-obvious-way-to-get-it-to-work tradition. Some bugs in Ghostscript's
2 and 4 bit color routines are scheduled to be fixed in 2.6, and at
that point I will try to implement an assembler image transformation
algorithm that someone sent me. That may speed things up a bit.

Color mapping has been fixed somewhat since 2.41. GS now searches
the available palette for the color nearest to the one it wants.
In 4-color resolutions, the resulting color may not be very close,
but if you are running GS with windows, you can change the colors
in the palette (using the control panel) to match the image.

Also, the screen driver should now adjust properly for the aspect
ratios of different screens.

In Atari 2.41 revision 1, support for windows was added to the screen
driver.  The driver consults the environment variable GS_WIN to
determine how windows will be handled.  If GS_WIN is unset, then no
windows are used.  If GS_WIN=interact, images are printed in windows,
but text mode is re-entered after each page.  This is to ensure that
the screen will be in the right mode when GS enters interactive mode.
I know of no way to tell from within GS which page is the last, so I
have to enter text mode after every page.  Finally, if GS_WIN=batch,
images are printed in windows, but text mode is never entered.  This
mode is useful when it is certain that GS will neither require input
from stdin nor send output to stdout.  Batch mode is used in gemGS, a
gem shell for Ghostscript.  Unfortunately, in batch mode, anything
written to stderr will obliterate the nice GEM screen. One day I may
get around to redirecting stdin, stdout, and stderr to a window, but
it hasn't been done yet.

The window that the image is printed in is a standard GEM window,
with all of the standard gadgets. Everything operates in the
normal fashion, except for the arrow buttons in the scroll bars.
These normally scroll one line, which makes little sense for an
image. So, I used these buttons for "top of page", "bottom of page",
etc.

2.) There are two ways to send output directly to the printer.
Including '-sOUTPUTFILE=PRN:' on the command line will send output to
the centronics port via gemdos.  The option '-sOUTPUTFILE=CEN:' will
write output directly to the centronics port.  The routines for direct
printer output were contributed by Chris Strunk (CS-TeX)--THANKS!
Direct centronics output is generally much faster (about a factor of 4
for heavy graphics). For some unknown reason, the CEN: option does
not work properly on some STEs and TTs. This is on my list of problems
to look at.

3.) ST-GS no longer recoginzes the nonstandard command line option
'-c<clist_size>' to specify the size of the buffer for band printing.
The new option is '-dBufferSize=<clist_size>'.  See use.doc.  If you
don't have enough ram to hold the complete bitmap of the image, you
can specify that the image be constructed in bands of size
'clist_size' (in bytes).  If the BufferSize option is absent, GS uses
a default buffer of 100K for images which are larger than the
available memory.

4.) Marcus Haebler has written a GEM image device and a 360dpi
NEC P6 device. THANKS MARKUS!

The number of available drivers has increased to the point that it is
not feasible to include all that an ST owner might reasonably use.
The current choice of 20 drivers was decided mostly by a vote of GS
users on the internet (a couple were included at my whim).  Type
'gs -h' for a list of the available drivers.

stvdi    - The screen device. Supports 1, 2, 4, and 8 bit color,
slm      - Atari SLM laser printer (thanks to Robert Stabl),
gemimg   - GEM bitmap format (thanks to Marcus Haebler),
djet500  - HP DeskJet 500,
djet500c - Color HP DeskJet 500,
laserjet - HP LaserJet,
bj10e    - Cannon BubbleJet,
epson    - Epson 9 and 24 pin printers (limited resolutions),
eps9high - High resolution Epson 9-pin device (makes multiple passes),
epsonc   - Color epson printers,
necp6     - NEC 360 dpi printer,
gifmono  - GIF monochrome bitmap format,
gif8     - GIF 8-bit color format,
pbmraw   - Mono portable bitmap format,
ppmraw   - Color portable bitmap format,
dfaxhigh - G3 fax format, high res,
dfaxlow  - G3 fax format, low res,
filter   - Filter device,
dps      - Display postscript (partial implementation),
level2   - Level 2 postscript (partial implementation).

Apparently the display postscript and level 2 postscript are only
partial implementations.  I am not able to test most of these devices,
so I cannot say how well they work (if at all).

The binary distribution contains the executables, a bunch of postscript
support files, some relevant docs, and the default Ghostscript font.
Since the changes to the standard Unix GS source are now trivial, I
have included the source files specific to the ST in the same archive.

The standard source and fonts for 2.52 (you can use the old fonts if
you want) are available from prep.ai.mit.edu and its mirror sites, and
a good number of other sites which carry unix source code.


MINIMUM CONFIGURATION:

I run ghostscript on a 4M 520ST with an 85M hard drive and a
monochrome monitor, so it is hard for me to estimate a minimum
hardware configuration.  The executable is now > 300K, so it is
unlikely that it will run on a 512K machine.  1M is a tight squeeze,
but it seems to be possible.  Keep in mind that a 300dpi image
requires a little over 1M of memory, so high resolution printing
requires either lots of memory or band printing.  Color is a real
memory hog, due to some limitiations of GS, so you may have to
decrease the resolution for color images (screen images cannot be
printed in bands).

GS also runs on TT's, although probably not as fast as it would if it
was compiled specifically for the 68030.  I leave it to someone else
to compile GS for the TT.  Compilation is just too damn slow on my ST.
The stvdi screen device should work in all ST resolutions, TT high, TT
medium, and perhaps TT low.

You can probably get by without a hard drive if you are willing to use
only the ghostscript default font.  The font files take up about 2-1/4
Meg of disk space.  For graphics, the default font is fine, but text
will be ugly.


INSTALLATION:

Ghostscript searches a default path '.,f:\gs,f:\gs\ps,f:\gs\fonts' for
the initialization files and the fonts.  To change this, define the
environment variable GS_LIB to be a COMMA separated path for
ghostscript to search.  If you specify file paths on the command line,
you may use either '/' or '\' as a path separator.

To install:

1) Copy gs252b.zoo to the desired directory (f:\gs to use the default
    search path).

2) Unpack the archive with 'zoo e// gs252.zoo'
    If you want the gs directory to be somewhere besides f:\gs,
    define the environment variable GS_LIB to be a comma
    separated search path which contains the files in the
    'ps' and 'fonts' directories.

USAGE:

To use ghostscript:

1) Type 'gs -r<width>x<height> file.ps' on the command line. Width
    and height are normally in pixels, but for the screen device
    they are interpreted as DPI. If the height is omitted, the
    argument to -r will be used for both the width and height.
    The default device is the screen at 80 dpi. You can specify
    as much resolution as you have memory for, but it may take forever
    to construct your image.

    Wait a while for the image to appear on the screen (this can be
    a long while for complicated files or high resolutions). You can
    use the cursor keys to scroll around the image. Press the <help>
    key for more info on the screen driver. Type <Q> to return to the
    GS interpreter. Then you can type PostScript commands to your
    heart's content.  Type 'quit' or <^D> to exit GS.

    If the environment GS_WIN is set to one of the values mentioned
    above, then the image will be displayed in a GEM window. In this
    case, you can move around the image with the scroll bars or the
    cursor keys. Look in the "About Stvdi" menu entry for a summary
    of available operations.

2) To get a printer device, type 'gs -sDEVICE=deskjet file.ps' for a
    deskjet, 'gs -sDEVICE=epson file.ps', etc. Type gs -h for a
    list of available printer devices. I defined an alias for the
    one that I use, i.e. "alias gsdj 'gs -sDEVICE=deskjet' " The
    printer output will be written in a file called 'gs_pr.XXX',
    where XXX is a unique number. See the docs for other ways to
    select a device or to see which devices are installed. Output
    can be redirected to a file of your choosing, or to the printer
    with the '-sOutputFile=' option. The option
    '-sOutputFile="|lpr"' will pipe GS output to lpr running under
    MiNT. OutputFile=PRN: or CEN: will send output directly to
    the printer port (CEN: prints faster, but is less compatible).

3) Send the file 'gs_pr.XXX' to the printer. Since it is a binary
    graphics file, you will need a print utility which does
    NOT try to add carriage returns and such at ends of lines.
    I wrote a small program to print these files, called 'bpr'.
    It was intended for a DeskJet, but it apparently works
    reasonably well with other printers. Bpr is available from
    lifshitz.ph.utexas.

KNOWN BUGS, LIMITATIONS and POSSIBLE PROBLEMS:

See the doc files and gs252.bugs for some known bugs and problems.
8-bit color may not work properly.

TIPS:

Here are a few miscellaneous tips.

1) Read the supplied documentation! There isn't much, but it is helpful
    and it is quicker than sending me questions. Use.doc is the
    most important file for casual users.

2) You can change the ghostscript prompt by editing the gs_init.ps file.
    Search the file for GS or >, and then change this to whatever you
    want the prompt to be. Many other changes can be made in this
    file to alter the behavior of GS. For example, you can redefine
    the 'showpage' command so that it doesn't wait around for a
    CR to be typed after every page.

3) There is a Unix newsgroup called gnu.ghostscript.bug, which you
    may want to have a look at--also comp.languages.postscript.

4) The ps directory contains some files on which to test ghostscript.
    These are some of the files that where used to test the port.
    Don't run escher.ps at 300 (or 360) dpi unless you have lots
    of time to waste.

5) GS can be used to view or print the output of dvips. The combination
    of TeX, dvips, and GS can be used to preview TeX documents (or
    PS output from word processors) on the screen at high resolution
    (if you need this sort of thing and have the memory). I have gone
    up to 300dpi and it seems to work OK. Dvips also allows PS
    graphics to be easily included in TeX documents.

6) There is now a graphical interface to GS, called gemGS. You may
    find it useful if you hate typing command lines. Also, gemGS
    allows the selection of individual pages from large documents,
    although this feature is rather slow. GemGS 1.2 is compatible
    with GS 2.41, and gemGS 1.3 is intended for GS 2.52.

ACKNOWLEDGMENTS:

Many kind people have contributed to the Atari version of Ghostscript.
Some of the more direct contributions are:

Hauke Hess:    Original screen driver upon which stvdi is based,
Robert Stabl:    The Atari SLM driver,
Chris Strunk:    Contributed code for direct centronics printing,
Marcus Haebler:    360 dpi NEC P6 and GEM image drivers,
J. Bammi:    For gcc, and numerous library bug fixes.

Please forgive me if I forgot to mention an important contribution.


FOR MORE INFO:

The original source files, docs, and fonts can be obtained from
many places. I obtained the ones I used from 'ftp.uu.net'.

Send bug reports to:

Tim Gallivan
Center for Relativity
University of Texas
Austin, TX
[e-mail]