Copyright (C) 1992 Aladdin Enterprises.  All rights reserved.

This file is part of Ghostscript.

Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the Ghostscript General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License.  A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities.  It should be in a file named COPYING.  Among other
things, the copyright notice and this notice must be preserved on all
copies.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

This file, history.doc, describes the changes in very old releases of
Ghostscript.  For more recent changes, see the NEWS file.

For an overview of Ghostscript and a list of the documentation files, see
README.

Version 2.3 (8/28/91)
===========

This is a minor release to fix two bugs and add the PaintJet driver, which
didn't make it into 2.2.

Utilities
---------

Changes the pstoppm utility so it counts pages correctly even in the
presence of arbitrary saves and restores.

Drivers
-------

Adds a new, "supported" PaintJet driver.

Changes the Epson driver to use ESC+D rather than ESC+\ for horizontal
positioning, since many printers don't support the latter.

Adds horizontal double-density (two-pass) printing to the Epson driver, so
it can do 240 x 60 and 360 x 180 densities.  (Vertical double density is
not supported yet.)

Version 2.2 (6/1/91)
===========

The purpose of this release is to add save/restore, and a few
miscellaneous Level 2 P*stScr*pt features such as undef.  It also includes
major improvements in graphics quality and in handling of high-resolution
printers.

Procedures
----------

Changes the version numbering to M.mpp rather than M.m.p, so that
`version' can be a real number for those programs that insist on it.

Renames ghost.ps as gs_init.ps, gfonts.ps as gs_fonts.ps, and statusd.ps
as gs_statd.ps.  The initialization files now all are named gs_*.ps.

Renames gdevs.{c,h,tl} as gconfig.{c,h,tl}.

Changes the relevant makefiles and command files so that a single build
can contain several drivers that share code, e.g., the Epson driver and
the DeskJet driver.

Changes gs_init.ps so it relies on an external gconfig.ps file rather than
making a specific test for the presence of Level 2 features.

Adds an entry for uglyr.gsf to the makefile.

Removes the distinction between CCA and CCNA, since most of the files now
contain constructs that require non-ANSI compilation on MS-DOS platforms.

Adds a `man' page for the ansi2knr utility.

Changes the documentation (use.doc) to show how to use -sDEVICE=<device>,
or the selectdevice procedure, to select devices by name.

Adds DEVICE_DEVS to the makefiles (analogous to DEVICES and DEVICE_OBJS).
This finally makes the make procedure fully automatic.

Adds the name of the initialization file (gs_init.ps) as a
platform-specific makefile parameter, GS_INIT.

Removes the test program gt.{c,tr} from the fileset, since it is not
useful to users.

Moves the Symbol encoding vector to a separate file (symbol_e.ps), from
which it is loaded when first used.

Changes the error handler so it can handle errors that occur while reading
the initialization files.

Extends ansi2knr so it can handle `void' and `...' in parameter lists.

Adds quit.ps to the set of installed files.

MS-DOS-specific changes
- - - - - - - - - - - -

Adds the VGA and BGI drivers to the standard MS-DOS configuration, and
makes VGA the default.

Adds a `+' and a newline at the end of gs.tr, to avoid problems with file
transfer programs or editors that add a newline at the end of files.

Changes the name of msdos.mak to turboc.mak, and creates a new tbcplus.mak
makefile for use with Turbo C++ and Borland C++.

Changes the extension of the loader response files from .tl to .tr.

Changes the default search path from c:/ghost and c:/ghost/fonts to c:/gs
and c:/gs/fonts.

Changes the directory separator from `|' back to ';', since it appears
that DOS can handle a ; in a command line if it is prefixed with \.

Unix-specific changes
- - - - - - - - - - -

Changes the uses of install in unixtail.mak so they only install a single
file at a time, which is all that the standard Unix install allows.

Removes the duplicate files (README/readme, LICENSE/license,
COPYING/copying, Fontmap/fontmap).

Changes the ld flags from LDPLAT to LDFLAGS.

Adds XCFLAGS and XLDFLAGS.  These are concatenated with CFLAGS and LDFLAGS
respectively.  The intention is that they be set from the `make' command
line if desired.

VMS-specific changes
- - - - - - - - - -

Repairs the omission of ZPACKED from the VMS build lists.

Drivers
-------

Fixes bugs:
	- The SunView driver produced semi-garbage on little-endian
platforms (Sun-386i) because it didn't swap the bit order.
	- The X driver would dump core if it couldn't open the display and
the DISPLAY environment variable wasn't set.
	- The X driver relied on white = 0, black = ones in a couple of
places;
	- The X driver would return an error, instead of clipping, if
asked to display outside the window.
	- The X driver would create inappropriately sized windows, because
it believed the server's report of the screen resolution.

Adds Fran Taylor's Private Eye driver to gdevs.mak and the fileset (not
supported by Aladdin Enterprises).

Adds Neil Ostroff's TruFax driver to gdevs.mak and the fileset (not
supported by Aladdin Enterprises).

Makes the scratch file template for the printer drivers a per-platform
quantity (gp_scratch_file_name_template).  Puts the default scratch files
for Unix in /usr/tmp rather than /tmp.

Changes the SunView driver to prevent the Ghostscript window from being
destroyed (which badly confuses the interpreter).

Extends the Epson driver to handle a variety of print densities in both X
and Y, to handle 24-pin as well as 8-pin graphics, and to allow optional
specification of default density in the makefile (gdevs.mak).

Refactors the printer drivers so that a single driver handles both DeskJet
and LaserJet.  Adds LaserJet drivers that use the new compression modes on
the LJ IId/IIp and LJ III.

Changes all the printer drivers to use band lists rather than bitmap
paging as the buffering method.  (The individual drivers need only a
one-line change to replace mem_copy_scan_lines with
gdev_prn_copy_scan_lines with a different argument.)

Adds the halftone phase as additional arguments to tile_rectangle and
tile_trapezoid.

Adds an entirely new and much simpler PaintJet driver, using the new band
list interface.

Adds margin information to the device structure.  This is currently only
relevant for printer devices.

Adds BGIPATH and BGIUSER environment variables, allowing additional
control of the BGI driver.

Changes the x/y_pixels_per_inch member of the device structure from int to
float.

Fonts
-----

Patches gs_fonts.ps so definefont will add an isFixedPitch entry to
FontInfo if there isn't one there.

Removes the old "type 7 path" encoding code from gs_fonts.ps.

Changes bdftops so it puts isFixedWidth and ItalicAngle entries in the
FontInfo dictionary of the fonts it creates, since some P*stScr*pt
programs rely on this.

Changes bdftops so it synthesizes as many missing characters as possible
out of the ones that are there (in particular: synthesizes accents out of
punctuation marks, and accented characters using seac.)  The results
aren't all that good, but they're a lot better than having characters
missing out of the font.

Utilities
---------

Adds a pfbtops utility for converting .PFB fonts to standard Ghostscript
fonts.

Fixes bugs:
	- ps2image didn't reset things properly between pages for
multi-page documents.

Interpreter
-----------

Makes Ghostscript recognize `-' alone as meaning that it should read from
standard input as though it were a file.  This allows Ghostscript to
accept a pipe as input.

Fixes bugs:
	- seac in type1addpath used the current font's encoding, not
StandardEncoding.
	- type1decryptfile (eexec) didn't recognize binary (as opposed to
hex) representation.
	- Mentioning a name whose value was a no-access object caused an
invalidaccess error.
	- There was a bogus definition of `run' in zfile.c.
	- The interpreter didn't handle end-of-file on stdin properly.
	- Real numbers with an 'e' or 'E' but no decimal point were not
recognized.
	- On MS-DOS systems, inside strings, \ followed by a newline was
not discarded properly.
	- On MS-DOS systems, the long unsigned divide routine sometimes
gave incorrect answers.  Among other things, this caused alternate-radix
numbers sometimes to crash the interpreter.
	- cvrs didn't do the right thing about reals or negative integers.
	- .echo.mode was being reset with def instead of store, and was
defined in systemdict rather than userdict.
	- setgray and settransfer didn't interact properly.
	- 16#80000000 was being interpreted as a signed integer (and
converted to a real) rather than an unsigned one.
	- atan returned 0 sometimes when it should have returned 180.
	- currentcmykcolor was defined wrong.

Removes the filename operator, since no standard Ghostscript code used it,
and it caused problems with some P*stScr*pt files.

Implements new operators: filenameforall, selectfont (as a procedure),
stringmatch, undef.

Adds new standard procedures: selectdevice.

For MS-DOS, requires that the operand and execution stacks be located in
the data segment, and uses short pointers to address them.  This produces
significantly smaller and faster code.  (These changes are not visible to
users or library clients.)

Changes the assignment of attribute bits, and adds new bits for
save/restore and the garbage collector.  Changes many of the macros in
store.h to support save/restore.  (These changes are not visible to users
or library clients.)  Implements save and restore.

Moves type names from gs_init.ps to ghost.h and ztype.c.

Moves error names from gs_init.ps to errors.h and iinit.c.

Introduces gp.h as a documented interface to the platform-specific files.

Adds the -- switch, which allows Ghostscript programs to take arguments
from the command line.

Changes many uses of the name `name' to something else, to avoid upsetting
the Microsoft C compiler.

Really implements packed arrays -- they took the same amount of space as
ordinary arrays in previous versions.

Changes exitserver in serverdict so that it just clears the stacks.  (This
isn't the correct fix, but it will do as a workaround.)

Makes many miscellaneous small changes to pacify various compilers.

Changes gs_fonts.ps so that when "quiet" mode is selected (-q switch),
Ghostscript doesn't print anything when loading fonts or when substituting
for undefined characters.

Defines the name consisting of just a control-D as a no-op, because some
P*stScr*pt-generating applications put control-Ds in their output.

Implements halftone phase (sethalftonephase and currenthalftonephase
operators).

Removes the -E switch, since it is no longer useful.

Changes the -w and -h switches to a single -g (geometry) switch, with
usage -g<width>x<height>.  Makes the -h switch, and a new -? switch, print
usage help.

Implements correct handling of stack overflow errors (makes an array out
of the contents of the overflowing stack, and resets the stack, before
invoking the error handler).

Adds t_oparray (`operators' defined as procedures) and the makeoperator
operator.  This is so that programs like the Distillery that rely on all
operators being bound by `bind' will work properly.

Adds a new NOPAUSE flag to suppress the prompt and pause at copypage and
showpage.

Library
-------

Fixes bugs:
	- gs_type1_interpret didn't store the encryption state or the skip
count before returning to let the client handle a seac or an endchar in
the middle of a seac.
	- The definition of the Type 1 operator ce_testadd was based on
wrong information; the operator takes only 2 operands and does something
unknown.
	- mem_true24_copy_mono wasn't incrementing the destination pointer
if the color was transparent, leading to garbled characters.
	- gx_lookup_fm_pair would sometimes look at one entry beyond the
end of the cached font/matrix pair area.  (This probably had no practical
effect.)
	- gs_type1_interpret didn't save the current point when returning
to the client for a callothersubr, causing some characters to be rendered
displaced (such as some of the chess pieces in chess.ps).
	- gs_setgray, gs_sethsbcolor, gs_setrgbcolor, gs_setflat, and
gs_setlinewidth gave errors for out-of-range operands rather than forcing
them into range.
	- Transfer functions were not actually supported.
	- The area fill algorithm failed on certain complex paths.
	- The current point was sometimes defined when a BuildChar
procedure was called.
	- Stroking a degenerate line didn't display anything for round
caps or joins.
	- If the ends of a curve had exactly the same X coordinate, the
curve sometimes wouldn't be displayed.
	- Very thin lines that went outside the clipping region would
sometimes be displayed as dashed, or not at all.
	- The translation in a FontMatrix was ignored.
	- Very wide, shallow lines would color extraneous pixels when
using bevel or miter joins.
	- Dashed lines didn't join properly at the beginning of a closed
path.
	- 0-degree arcs didn't add the appropriate line (possibly
degenerate) to the path.
	- gs_type1_interpret didn't reset the callsubr stack when starting
the base character of a seac, which caused confusion if the accent's
endchar fell inside a Subr.
	- Non-monochrome memory memory devices weren't checking the
arguments of the drawing procedures properly.
	- The initial clipping rectangle for memory devices was being
computed wrong.
	- Null devices had a semi-infinite clipping rectangle instead of
an empty one.
	- gs_setlinewidth was treating negative arguments as zero, instead
of taking the absolute value.
	- imagemask with a dithered color used a solid color rather than
the dithered one.

Tweaks the area fill and image rendering algorithms to be a little more
liberal with paint when being used to render characters.

Changes the name of the 8-bit mapped color memory device from
mem_mapped_color_device to mem_mapped8_color_device.

Changes the memory devices so that on little-endian platforms, they can
store the bytes within a word in either order.  (Little-endian order
allows efficient 32-bit updating, big-endian is required when displaying
or writing to a printer or a file.)

Implements halftone phase.

Replaces the trapezoid fill algorithm with a much more accurate one
inspired by a contribution from Paul Haeberli.  This also changes the
graphics convention back to filling only pixels whose center falls within
the region to be filled.

Changes the character cache to allocate headers and bits contiguously out
of a single ring buffer.

Changes gs_imagemask and gs_imagemask_init to take a thickness adjustment
parameter.

Changes gs_setcachedevice and gs_setcharwidth to take the graphics state
as a parameter.

Renames gx_device_memory_bitmap_size as gdev_mem_bitmap_size,
mem_copy_scan_lines as gdev_mem_copy_scan_lines, and
mem_bytes_per_scan_line as gdev_mem_bytes_per_scan_line.

Version 2.1.1 (1/15/91)
=============

This is a sub-release distributed to fix a few early bugs in 2.1, just in
time for the new GNU master tape.

Build procedures
----------------

Removes all of the (undebugged) Level 2 code from the fileset, as well as
the (unused) file gdevvga.c.

Changes the tar file so that the files are stored in the directory
gs<version> rather than simply gs, e.g., gs211.

Interpreter
-----------

Changes the scanner so that \ is recognized within strings regardless of
whether the scanner is reading from a string or from a file.  This is
compatible with newer P*stScr*pt interpreters, and with the newer
P*stSc*pt language specification, but not with the older specification in
the original PostScript Language Reference Manual.

Drivers
-------

Fixes the max_value macro in gdevmem.c so that compilers won't complain
about a left shift by 32.

Adds 'byte' to the list of types that gdevx.c must sidestep because header
files use them.

Library
-------

Changes the computation of penum->unpack in gsimage.c so as not to upset
compilers that don't treat procedures and pointers to procedures as
compatible types for conditional expressions.

Version 2.1 (12/31/90)
===========

This is primarily a bug fix release to clean up problems in 2.0.  It also
implements a first cut at the new color operators.

Build procedures
----------------

Changes the separator for multiple directories in MS-DOS from ';' to '|',
since there is no way to include a ';' in a command line.

Adds <dir>/fonts to the default search path, where <dir> is c:/ghost for
MS-DOS systems and `pwd` for Unix systems.

Adds new documentation describing how to direct output to the printer.

Changes the PROCTYPE and USE8087 options in MSDOS.MAK to CPU_TYPE and
FPU_TYPE.  The latter now indicates the type of FPU to generate code for,
if any.

Drivers
-------

Adds a driver for the Canon BubbleJet BJ10e.

Modifies the EGA driver to handle (non-standard) frame buffers larger than
64K.  Adds drivers for the VGA and for the EIZO MDB-10 (a 1024 x 768 frame
buffer).

Changes the X driver so that it clips to the window dimensions, rather
than reporting an error.

Notes that the H-P LaserJet driver, like the DeskJet driver, works under
Unix as well as MS-DOS.

Adds support for 120 X DPI mode, and for the LQ-1500, to the Epson driver.

Fonts
-----

Fixes bugs in bdftops:
	- It was using /UniqueId instead of /UniqueID as the key for the
font unique ID.  This effectively disabled the font cache.
	- The definition for .notdef was bogus -- an invalid CharString.

Changes ghost.ps and gfonts.ps so that NullFont is the initial font,
rather than Ugly.

Arranges things so that when attempting a font substitution, if the
default font is not found, NullFont is used instead.

Extends bdftops so that if certain easily synthesized characters are
missing from a font, it will attempt to synthesize them using available
characters.

Interpreter
-----------

Extends the -T switch to allow specifying a printf template for the
arguments of the procedure being traced.

Fixes bugs:
	- /0 was interpreted as equivalent to 0 (a number) rather than a
literal name.
	- packedarray was defined as being like array, instead of like
array followed by astore.
	- Many minor and harmless type mismatches (and a couple of very
minor genuine bugs) were upsetting the Apollo C compiler.
	- exp was incorrectly failing in certain cases with a negative
first argument.
	- copyscanlines incorrectly required at least 4 elements on the
operand stack, although it correctly only used the top 3.
	- readhexstring incorrectly read 1 byte even if the string length
was zero.
	- Not every place that expected an array would accept a packed
array.
	- Very complex paths (and infrequently other things) could produce
a 'memory leak'.
	- / alone would skip following whitespace and gather following
characters, rather than creating an empty name.
	- ghost.ps left newerror defined as true in $error, which resulted
in an erroneous error report if a program executed a 'stop'.
	- The definition of exitserver in serverdict didn't clear the
stack.
	- currentfile returned an executable file, rather than a literal
one.
	- setfont for Type 1 fonts didn't check the UniqueID in the font
dictionary against the one in the font's Private dictionary.
	- A value stored in a dictionary under the key /xxx couldn't be
retrieved using the key (xxx), and vice versa.
	- charpath with a Type 1 font on a string containing a 'space'
would produce garbage (it released the parent path inappropriately).
	- bytesavailable did not work properly for terminal input.

Changes the interface to the memory allocator so that it always takes an
element size and an element count, like calloc instead of malloc (but note
that alloc does *not* clear just-allocated blocks).  Gets rid of the
special 'dynamic' allocation procedures.

Changes the random number operators to use a better implementation.

Changes the idiv operator so it will accept any numbers, not just
integers, as arguments.  (The PostScript manual doesn't allow this, but
implementations apparently do.)

Provides semi-fake but usable definitions for all of the color PostScript
extensions, including a real implementation of colorimage.

No longer uses the name 'null', which is apparently reserved by Microsoft
C.  Makes a number of other minor changes required to pacify the Microsoft
C compiler.

Implements %statementedit and %lineedit.  (%statementedit is equivalent to
%lineedit, which is wrong.)  Changes the interactive interpreter to use
%statementedit.

Changes the scanner to accept null, ctrl-K (vertical tab), and ctrl-L
(form feed) as whitespace.  Ctrl-L terminates a comment, null and ctrl-K
do not.

Allows a literal string as the 'proc' argument(s) for image, imagemask,
and colorimage.

Adds the following operators/procedures: arct, cleardictstack, deletefile,
renamefile.

Defines =print as a synonym for =, for the benefit of LaserPrep.

Implements non-zero PaintType for the show operators (but not for
charpath) for Type 1 fonts.

Adds the ISOLatin1Encoding encoding vector.

Renames currentcolor and setcolor as currentgscolor and setgscolor, to
avoid conflict with the Level 2 PostScript names.  Removes colorhsb,
colorrgb, hsbcolor, and rgbcolor.

Library
-------

Fixes bugs:
	- In a couple of places, a 0 was being passed as a pointer
argument without casting, which confused the Microsoft C compiler.
	- Image devices were not recognized properly in debugging
configurations.
	- Inverted-color monochrome image devices were not recognized
properly.
	- Images that exactly fill the drawing area rendered very slowly,
because they erroneously used the general clipping algorithm.
	- Images that are 1-for-1 with the device were incorrectly scaled
by a factor of 8 in X.
	- Rounding artifacts sometimes caused characters to be unevenly
offset vertically by 1 pixel.
	- Type 1 fonts that used the Flex feature resulted in garbled
images.
	- The show operator routines would incorrectly fill or stroke a
path that existed at the time the show was started.
	- setscreen truncated the cell size instead of rounding, which
could produce off-by-1 anomalies.
	- stroke would sometimes produce garbage (or nothing at all) for
very narrow lines.
	- path filling would only color the pixels whose centers fell
inside the path: the Adobe specification requires coloring a pixel if any
part of it falls inside the path.

Changes the Epson printer driver so that it drives the printer directly
rather than writing to a file.

Changes pathbbox so that if the path is empty but there is a current
point, it returns a null rectangle at the current point.

Changes gs_image_init to take an additional parameter (after bps) giving
the number of samples per pixel (1, 3, or 4), and an indication of whether
the samples for each pixel are together or separated (-3 or -4).

Renames the gs_image_data and gs_imagemask_data procedures as gs_image and
gs_imagemask, and removes the old versions of the latter.

Adds gs_colorimage.

Replaces Snoopy's color dithering algorithm with one contributed by Paul
Haeberli.

Changes gs_setgray, gs_[set]hsbcolor, and gs_[set]rgbcolor so that they
coerce arguments outside the range [0..1] back into the range, instead of
signalling an error.

Makes a number of minor changes required to pacify the Microsoft C
compiler.

Changes gs_arcto so that if the last argument is a null pointer, the
tangent points are not returned.

Removes gs_type1addpath, which is not useful.  (Clients must call
gs_type1_init and gs_type1_interpret directly.)

Implements the 'seac' opcode for Type 1 fonts, allowing fonts with accented
characters to display properly.

Implements the undocumented 'testadd' opcode for Type 1 fonts, which is
used by some Adobe fonts.

Renames gs_currentcolor and gs_setcolor as gs_currentgscolor and
gs_setgscolor.  Removes gs_colorhsb, gs_colorrgb, gs_hsbcolor, and
gs_rgbcolor.

Version 2.0 (9/12/90)
===========

The main purpose of this release is to add fonts, support for multiple
devices, and imaging into memory.  It also fixes a number of miscellaneous
bugs.  (Unfortunately, accurate records of the bugs fixed are not
available.)  The changes were so extensive that we chose to increment the
major version number.

Miscellaneous
-------------

Doesn't attempt to open the .MAP file on Unix systems.

Adds mention of statusd.ps to interp.doc.

Notes that Turbo C 2.0, not 1.5, is required for building the MS-DOS
version.

Adds a DEVICES= line to the makefile, and allows multiple devices.

Documents, in interp.doc, the X Windows resources that Ghostscript
recognizes.

Adds three PostScript masters to the fileset: chess.ps (+ cheq.ps),
golfer.ps, and escher.ps.

Drivers
-------

Changes the names of all the device drivers.  See gdevs.mak for the
updated list.

Adds a (working) driver for SunView.

Adds drivers for the Sony NeWS frame buffer, and the Sony Microsystems
NWP533 printers.  These drivers were contributed by users, so we aren't
prepared to answer questions about them.

Adds a driver for the Borland Graphics Interface (BGI) for MS-DOS systems.
Note that to use this driver with a non-EGA/VGA display, you need a .BGI
file appropriate for your hardware.  (The Ghostscript executable includes
the EGA/VGA driver.)

Adds a driver for Epson printers.  The driver has only been tested on an
LX-800, and on an H-P DeskJet in FX-80 emulation mode, but may work on
other models.  The driver could be adapted to work on Unix systems, but as
distributed, it only works on MS-DOS systems.

Adds a driver for the Hewlett-Packard DeskJet printer.  The driver could
be adapted to work on Unix systems, but as distributed, it only works on
MS-DOS systems.

The X Windows driver no longer waits for the user to type a character
before bringing up the initial display.

Adds information to drivers.doc describing how to change the definition of
the device structure and procedure table.

Extends the tile_rectangle and tile_trapezoid driver procedures to
interpret color0 = color1 = gx_no_color_index as meaning that the tile is
actually colored, not a mask.

Build procedures
----------------

Changes the tar file so it puts everything in a directory called gs.

Removes the -ansi switch for gcc (this was causing problems with <math.h>
on some systems).

Changes LDPLAT to the string -X, which is appropriate for most Unix
systems (but not for SunOS 4.n).

Adds EXTRALIBS to the makefile, for specifying additional libraries to be
linked in.

Adds a 'clean' target for 'make', to get rid of all temporary files, the
binaries, and the executable.

Changes names of system-specific files from gp-xxx.c to gp_xxx.c.

Adds support for VMS (gp_vms.c and ghost.dcl).

Creates a new file gdevs.mak, and reorganizes the other makefiles, so that
the choice of which device driver(s) to include is isolated in a single
line in the platform-specific makefile.

Changes the standard MS-DOS makefile so it builds for 8088/86 (not 80386),
with neither -DNOPRIVATE nor -DDEBUG.

Changes the name of the MS-DOS makefile from dos-ega.mak to msdos.mak, and
the Unix makefiles from ux-[g]cc-x.mak to unix-[g]cc.mak.

Updates drivers.doc to describe how to add new drivers in gdevs.mak.

Removes gdevs.ps: the drivers are now responsible for specifying the size
of the imaging region.

Interpreter
-----------

Adds a makefile macro GS_LIB_DEFAULT and an environment variable GS_LIB to
define a search path for the library (initialization and font) files, and
implements the -I switch for the same purpose (replacing -sLIB=, which was
never actually implemented).  See interp.doc for details.

No longer clears the operand stack between interactive inputs.  No longer
prints the contents of the operand stack after every input in debug mode.

Doesn't "eat" the character that the user types to proceed after a
showpage, unless it's an isolated <return>.

Changes the prompt so that it says
	GS>
if the operand stack is empty, or
	GS<n>
if there are n > 0 elements on the operand stack.

Adds -w and -h switches to the command line, equivalent to -dWIDTH= and
-dHEIGHT= except that they require numeric arguments.

Adds -q (quiet startup) switch to the command line, which suppresses some
initial messages and also has an effect equivalent to -dQUIET.

Fixes bugs:
	- = and == caused an error on some kinds of objects if the object
didn't have read access.
	- cvs didn't print operator names.
	- The definition of dynamic_begin in iscan.c caused the DEC VMS C
compiler to produce incorrect code.
	- mul didn't return a correct (real) result when multiplying a
very large integer by an integer that wasn't very large.
	- eq and ne didn't work on files, fonts, save objects, and some
operators.
	- The scanner would sometimes blow up on floating point numbers
beginning with a '.'.
	- flushfile didn't pop its argument from the stack.
	- put and putinterval would store into a packed array.
	- a few operators didn't check properly for stack underflow.
	- cvrs produced wrong output for radix values greater than 10.
	- The scanner would convert upper-case letters in alternate-radix
numbers wrong on Unix systems.
	- String comparisons other than equality often produced the wrong
result if the strings were of different lengths.
	- An ifelse as the last thing inside a forall would confuse the
execution stack.
	- There were some omitted casts and 'private' declarations that
made the GNU compiler unhappy.
	- There was a memory leak in the image[mask] operators that caused
516 bytes to be permanently lost each time one of them was used.
	- Quoted strings of length greater than 50 and less than 100 would
get mangled when being read in.
	- The scanner didn't consume the whitespace character following a
token, so programs that read data out of the program file could get
confused.
	- Under rare circumstances, an object of size between 249 and 255
bytes could get allocated on top of another object.

Allows bind to bind packed arrays, even though they aren't normally
writable.

Changes the length operator to allow a name as the argument.  (The
PostScript manual doesn't allow this, but implementations apparently do.)

Changes the setcachedevice operator to allow the bounding box to be
specified as a 4-element array instead of 4 scalars.  (The PostScript
manual doesn't allow this, but implementations apparently do.)

Removes a line from ghost.ps that accidentally disabled the font cache.

Implements memory devices (makeimagedevice, copyscanlines, and makedevice
for image devices).  makeimagedevice is implemented only for 1, 8, 24, and
32 bits per pixel.

Changes the deviceparams operator so it pushes a mark on the stack below
the parameters.  This is to allow for devices that have more than the
standard set of parameters.

Replaces defaultdevicename with two new operators, getdevice and
devicename.

Adds a flushpage operator that flushes any outstanding buffered output to
the screen.  This is not the same as copypage: on printers, copypage
actually prints a page, whereas flushpage may do nothing; on displays,
flushpage and copypage may both flush output to a server.

Adds an unread operator for pushing back a character into a file.

Adds a description of proposed grayimage and colorimage operators to
ghost.doc, even though they aren't implemented yet.

Changes the name of the currentfileposition operator to fileposition.

Removes the framedevice operator, since the new device operators supersede
it.

Adds a writeppmfile operator, for writing the contents of a memory device
to a ppm file.

Makes Ghostscript work even when the >> operator doesn't sign-extend
negative numbers.  (This has not been tested.)

Adds the Symbol encoding to ghost.ps.

Adds two new file-related operators, filename and findlibfile.  See
ghost.doc and interp.doc for details.

Adds type1encrypt and type1decrypt operators for manipulating Adobe Type 1
encoded fonts.

Changes the imagecharpath and addcharpath operators to type1imagepath and
type1addpath.  These operators now work with the Adobe Type 1 font
encoding.

Adds the type1decryptfile operator for reading Adobe Type 1 encrypted
fonts.

Library
-------

Fixes bugs:
	- curveto and lineto didn't check for the current point being
defined.
	- stringwidth would fail if there was no current point.
	- There were omitted casts that made the GNU compiler unhappy.
	- Line caps and joins didn't always work.
	- Dashed lines didn't work at all.
	- If you read out the current matrix while inside a BuildChar
procedure, the result was garbage.
	- image[mask] would crash if you gave it a single string with more
than 64K-1 pixels (MS-DOS only).
	- Filling with a gray pattern sometimes wrote into pixels beyond
the right edge of the region (MS-DOS only).
	- The font cache would mistake fonts for each other if both fonts
had a default (unsupplied) "unique ID".
	- When a character was entered into the font cache for the first
time, sometimes it would display as garbage and/or displaced vertically
from its proper position.

Implements gs_makeimagedevice, gs_copyscanlines, gs_getdevice,
gs_devicename, gs_flushpage, gs_writeppmfile, gs_type1encrypt,
gs_type1decrypt, gs_type1imagepath, and gs_type1addpath procedures
corresponding to the new operators in the interpreter (see preceding
section).

Changes [gs_]setdevice so that it does an erasepage when it first opens
the device.

Changes definition of gx_device structure as follows.  NOTE: THIS AFFECTS
ALL DRIVERS.

	- Removes bits_from_MSB (which wasn't actually used, in any case).
	    Ghostscript now assumes officially, as it always did in
	    practice, that device bitmaps are stored MSB first, i.e., X=0
	    corresponds to the 0x80 bit in the first byte.

	- Removes the initial_matrix member, which wasn't actually being
	    set up.

	- Adds a new member 'name', a string giving the device name.

	- Adds new members 'x_pixels_per_inch' and 'y_pixels_per_inch'.
	    These are only used by the default initial_matrix procedure
	    (see below).

	- Adds a new procedure 'output_page'.  The default implementation
	    (gx_default_output_page) just calls the sync_output procedure.

	- Adds a new procedure 'get_initial_matrix'.  The default
	    procedure uses the width, height, and x/y_pixels_per_inch
	    members to compute the matrix, assuming that X values run from
	    right to left, and Y values run from top to bottom.

Changes the names of the allocation procedure types gs_proc_alloc and
gs_proc_free to proc_alloc_t and proc_free_t, and moves them from gs.h to
std.h.

Makes Ghostscript work even when the >> operator doesn't sign-extend
negative numbers.  (This has not been tested.)

Version 1.3 (6/20/89)
===========

This release should have had a lot more things in it, but time pressure
and the already long delay in getting it out made it necessary to push it
out the door in an incomplete state (e.g., no testing on X systems
whatsoever).

Interpreter
-----------

Makes -d and -D equivalent on the command line.  Adds a new switch -s / -S
that defines a name as a string rather than a token.

Arranges things so that if -sLIB=_a_prefix_ is defined on the command
line, (filename) run will look for _a_prefix_filename before giving up if
filename isn't the name of an accessible file.

Changes showpage from an operator to a procedure.  The definition of
showpage in ghost.ps does a copypage, beeps the console, waits for the
user to type a character (normally a <return>, since line buffering is
always enabled), and then does an erasepage and an initgraphics.

Adds a new initialization file, gdevs.ps, containing device-dependent
parameters.  The default window size for X Windows is properly set to 612
x 792, i.e., 8.5" x 11".

Adds a new optional initialization file, statusd.ps, that provides dummy
definitions for the names found in statusdict on LaserWriters.

Adds a new operator, getenv, to get information from the shell
environment.

Adds a new predefined operator, defaultdevicename, that returns either (X)
or (EGA) according to how the interpreter was built.

Adds a new type, devicetype, and new operators deviceparams, getscanlines,
makedevice, makeimagedevice, and setdevice.  Changes currentdevice to
return a device object rather than a set of parameters.

Makes the scanner recognize reals with 'e' exponent notation, and handle
reals with more than 9 digits.

Fixes a bug that made names starting with digits read incorrectly.

Fixes a bug in the exp operator that made it not pop its first argument
from the stack.

Fixes a bug in the rand operator that made it return negative values about
half the time.

Fixes a bug in equality comparison (eq, ne, and several other operators)
that made unequal operator objects occasionally appear to be equal on DOS
systems.

Fixes a bug in the bind operator that made it not work on packed arrays.

Changes the internal representation of dictionaries so they can be
expanded or contracted dynamically.  Adds a new operator, setmaxlength, to
change the allocated size of a dictionary.

Changes sstorei.h so that non-DOS compilers don't encounter the #pragma
directive used by Turbo C.

Restores the display mode (on MS-DOS systems) when exiting.

Fonts
-----

Makes undefined characters in the standard font display as tilde rather
than blank (or causing an error).  Unmapped character codes (those mapped
to .notdef in the encoding) still display as nothing, per the PostScript
manual.

Library
-------

Adds a new header file, gxbitmap.h, with some new documentation describing
the internal storage format for bitmaps.

Makes numerous internal changes in the character / font cache, affecting
many of the routines in gxcache.c.

Fixes a bug in gz_draw_line / gz_fill_trapezoid that made nearly
horizontal lines display wrong.

Fixes a bug in gs_scale that made scaling not work if the coordinate
system was rotated or skewed.

Extends the font cache so it will handle characters rotated by multiples
of 90 degrees.

Changes the second argument of gx_path_bbox and gx_path_is_rectangle to be
a gs_fixed_rect * rather than a fixed [4].

Changes gs_matrix_rotate so it handles multiples of 90 degrees as a
special case.

Changes the definition of the gx_device structure to accommodate the new
device operators, and adds corresponding library calls.

Changes the type for a device color index from int to gx_color_index
(equivalent to unsigned long).  ***NOTE***: this affects existing clients
and drivers in a non-trivial way on MS-DOS systems.

Changes gs_malloc and gs_free to take a client name string as an argument.

Usage procedures
----------------

Changes the compilation rules for Unix systems to not use the -o and -c
compiler flags together, to be compatible with more versions of cc.

Changes the gcc makefile to use $(GCC) rather than gcc as the compiler
name.

Moves the -1 flag for the MS-DOS compiler from the cc*.bat files to the
makefile.

Changes CCDEBUG to CCFLAGS, and adds ASMFLAGS, in DOS makefile.

Adds -DFOR80386 and /DFOR80386 to enable use of 80386 instructions in
assembly code on DOS systems.

Merges the DEBUG and gs_DEBUG switches.  There is now only a single DEBUG
switch that affects both the interpreter and the library.

Adds a new compilation switch, -DNOPRIVATE, that makes private (static)
variables and procedures public for debugging and profiling (only needed
on DOS systems).

Adds the DOS executable (gs.exe and gs.map) to the distribution fileset.

Adds new platform-specific code files, gp-*.c, for a few things like
reading the clock.

Adds a new documentation file, drivers.doc, that describes the interface
between Ghostscript and device drivers.

Version 1.2 (2/22/89)
===========

Interpreter
-----------

Adds the new facilities in version 25 of PostScript: //name for immediate
lookup, packed arrays (setpacking, currentpacking, packedarray operators),
and new font cache parameters (setcacheparams, currentcacheparams
operators).

Adds new operators (setfileposition, currentfileposition) for random
access to files.

Extends readhexstring to take either a string or a file, just like token.

Fixes a bug that caused the 'for' operator (and a couple of others) to
randomly smash memory locations on PC platforms.

Library
-------

Renames the init_device driver procedure as open_device, and adds a
corresponding close_device.

Adds new procedures to read and set the cache limit values (implementing
the currentcacheparams and setcacheparams operators).

Usage procedures
----------------

Changes the name of the Unix makefile to ux-cc-x.mak, and adds a new Unix
makefile, ux-gcc-x.mak, for using gcc instead of cc.  (The latter doesn't
actually work yet.)

Changes the name of the single built-in font from uglyfont.cp to
ugly10.cp.

Version 1.1 (2/12/89)
===========

Interpreter
-----------

Makes the scanner treat ^Z (ASCII code 26) as whitespace: it erroneously
treated ^R (ASCII code 22, or octal 26) as whitespace.

Makes the token and readline operators, and the syntax for comments,
recognize \r (code 13), \n (code 10), and \r\n as equivalent end-of-line
indicators.  The token and readline operators will skip over any of these
sequences at the end of a token or line respectively, and a comment will
read through any of these sequences.  The other file operators (read,
write, readstring, writestring) do nothing special with these characters.

Changes the debug switch name from -D to -Z.  Adds a -D switch for
defining names in systemdict from the command line.  Defines -DDEBUG for
printing out debugging information during initialization, and -DNODISPLAY
for suppressing display output.

Corrects a bug that prevented the error machinery from working -- in
version 1.0, errors always dumped the stacks and aborted interpretation.

Corrects a bug that made eq and ne not work for strings.

Makes the atan (arctangent) operator normalize its results according to
the PostScript convention.

Makes the div operator check for zero divisor.

Makes unimplemented operators (resetfile, echo, save, restore, strokepath,
reversepath) truly undefined.

Makes the interactive loop exit gracefully on end-of-file: in version 1.0
this caused an infinite loop.

Implements the status operator.

Corrects a bug that made the 'for' operator deliver garbage values if one
or more of the operands (start, increment, end) was a real.

Corrects a bug that made the arc and arcn operators not pop their operands
from the stack.

Corrects a bug that made the kshow operator crash the interpreter.

Corrects a bug that made the print operator fail on machines that don't
pass structure arguments by simply pushing the contents of the structure.

Adds a new operator, imagecharpath, to convert images to
addcharpath-compatible outlines.

Changes alloc and alloc_free to use char * rather than byte *, and
alloc_free to return void rather than int, making them compatible with the
library's expectations and with malloc/free.

Explicitly casts all expressions of the form (ptr1 - ptr2) used as
procedure arguments to unsigned, to handle an incompatibility between
Turbo C versions 1.5 and 2.0.

Changes some of the internal conventions for operators: operators that
push on the operand stack must check for overflow explicitly, and
operators that modify the execution stack must return a special code.
(See oper.h for details.)

Initialization (ghost.ps, gfonts.ps)
--------------

Modifies ghost.ps and gfonts.ps so they print debugging information only
if the name DEBUG is defined.  (Presumably the user will set this from the
command line with -DDEBUG.)

Changes ghost.ps so it initializes the nominal screen size to 640 x 350 on
MS-DOS systems as before, but to 612 x 792 on Unix systems, which is an
8.5" x 11" page at 72 pixels per inch.

Library
-------

Corrects a bug that made the fill and eofill operators (gs_fill and
gs_eofill) not perform a newpath afterward.

Corrects the bug that made thin, nearly horizontal lines display wrong (as
a series of disconnected dots) in the MS-DOS implementation.

Fixes a bug in the EGA driver that often made it fill rectangular regions
with black around information being displayed in white.

Completely changes the internal representation of outline fonts, and
changes btoi.ps (a Ghostscript language program for converting bitmaps to
outlines) to use a new library call, gs_imagecharpath.

Changes the extension for outline font files from .gf to .cp.

Adds a new debugging switch, q, that traces all rectangle fill operations.

Adds a new debugging switch, v, that traces all device-level output calls.

Explicitly casts pointer differences passed as procedure arguments, as in
the interpreter.

Makes stringwidth work if there is no current point.  In version 1.0, this
gave a nocurrentpoint error.

Usage procedures
----------------

Changes the name of the 'read me' file from READ.ME to README.

Removes a bogus line (invoking the 'mcopy' utility) from the makefile.

Splits up the makefile into a generic part (ghost.mak) and
platform-specific parts (dos-ega.mak, unix-x11.mak).  The latter are what
is actually executed.

Puts the definitions of the DEBUG and gs_DEBUG compilation flags into the
makefile instead of in ghost.h and gx.h respectively.

Changes the names of the documentation files to be a little less cryptic.
Changes all the file names to lower-case in the documentation.  Adds
installation information to make.doc.

Changes all function definitions (but not prototype declarations) to ANSI
syntax, and adds a preprocessing step (ansi2knr) to convert them to K&R
syntax on Unix systems.

Changes the normal MS-DOS link configuration to not assume the presence of
an 80x87 coprocessor, and describes how to increase performance if a
coprocessor is present.

Changes the names of all the interpreter .c files, except stream.c, to
begin with 'i'.

Version 1.0 (8/11/88)
===========

First version released to the public.