Read Me(ucsd-psystem-xc)                              Read Me(ucsd-psystem-xc)



NAME
       ucsd-psystem-xc - UCSD p-System Pascal cross compiler

DESCRIPTION
       The ucsd-psystem-xc package is a collection of tools for compiling
       Pascal source files to produce UCSD p_System code files.  The package
       includes:

       ucsdpsys(1)
               A laucher to run the virtual machine comfortably from the
               command line.  It includes a batch mode for automating
               (scripting) operations.

       ucsdpsys_assemble(1)
               The cross assembler.  It is able to assemble several different
               target microprocessor architectures in the one executable.

       ucsdpsys_compile(1)
               The cross compiler.  It understands the UCSD Pascal dialect,
               including UNIT definitions and references.

       ucsdpsys_depends(1)
               May be used to determine include file dependencies, for use
               with make(1) and other build tools.

       ucsdpsys_disassemble(1)
               For disassembling UCSD p-System code files.  This is used to
               verify the correctness of the compiler.

       ucsdpsys_downcase(1)
               A untility for converting Pascal code to lower case, leaving
               string constants and comments unaltered.

       ucsdpsys_errors(1)
               A utility to translate back and forth between text and binary
               representations of the assembler error message files.

       ucsdpsys_libmap(1)
               A utility for printing segment maps of UCSD p-System library
               files.

       ucsdpsys_librarian(1)
               A utility for manipulating the segments within UCSD p-System
               codefiles.

       ucsdpsys_link(1)
               A utility for linking UCSD p-System codefiles to their
               assembler components.

       ucsdpsys_opcodes(1)
               A utility to translate back and forth between text and binary
               representations of the assembler opcode files.

       ucsdpsys_setup(1)
               A utility to translate back and forth between text and binary
               representations of the system.miscinfo file.

   Sister Projects
       Some other projects will be of interest to you.

       ucsd-psystem-fs
               This package contains tools for manipulating UCSD p-System
               floppy disk images, and a file system for mounting them in
               Linux as real file systems.
               http://ucsd-psystem-fs.sourceforge.net/

       ucsd-psystem-os
               This project provides a self-hosting set of system sources.
               You need the disk images produced by this project for the
               virtual machine to have a "system.pascal" file to run (this
               provides runtime support and the user command executive).  This
               is a work in progress.

       uvsd-psystem-vm
               This package provides a fully featured UCSD p-Machine emulator.

ARCHIVE SITE
       The latest version of ucsd-psystem-xc is available on the Web from:

           URL:    http://ucsd-psystem-xc.sourceforge.net/
           File:   ucsd-psystem-xc-0.13.README   # Description, from the tar file
           File:   ucsd-psystem-xc-0.13.lsm      # Description, LSM format
           File:   ucsd-psystem-xc-0.13.tar.gz   # the complete source
           File:   ucsd-psystem-xc-0.13.pdf      # Reference Manual

BUILDING ucsd-psystem-xc
       Full instructions for building ucsd-psystem-xc may be found in the
       BUILDING file included in this distribution.

COPYRIGHT
       ucsd-psystem-xc version 0.13
       Copyright (C) 2006, 2007, 2010, 2011, 2012 Peter Miller

       This program is free software; you can redistribute it and/or modify it
       under the terms of the GNU General Public License as published by the
       Free Software Foundation; either version 3 of the License, or (at your
       option) any later version.

       This program is distributed in the hope that it will be useful, but
       WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
       General Public License for more details.

       You should have received a copy of the GNU General Public License along
       with this program. If not, see <http://www.gnu.org/licenses/>.

       It should be in the LICENSE file included with this distribution.

AUTHOR
       Peter Miller   E-Mail:   pmiller@opensource.org.au
       /\/\*          WWW:      http://miller.emu.id.au/pmiller/

RELEASE NOTES
       This section details the features and bug fixes of each of the
       releases.

   Version 0.13 (2012-Nov-12)
       * The ucsdpsys_charset(1) command now understands more font file
         formats, including Terak and PSF Tools format.

       * The ucsdpsys_charset(1) command has a new -negative option, that is
         used to calculate the inverted "top half" of a font from the normal
         "bottom half", as is common in Terak fonts.

       * The ucsdpsys_charset(1) is now able manipulate the boot logo in Terak
         system.charset files.

       * The ucsdpsys_osmakgen(1) command now takes advantage of recent
         ucsdpsys_osmakgen(1) features.

       * There is a new ucsdpsys_foto(1) command, used to convert UCSD Pascal
         .foto files into .png files, and vice versa.

   Version 0.12 (2012-Nov-02)
       * The ucsdpsys_osmakgen(1) command now understands how to process
         SYSTEM.CHARSET files.

       * There is a new ucsdpsys_osmakgen(1) option called --arch-from-host,
         that may be used to translate a host name (e.g. "Terak") into an arch
         name (e.g.  "pdp11").

       * The ucsdpsys_charset(1) command now understands a
         --architecture=terak option, which means to work on a SYSTEM.CHARSET
         file suitable for a Terak system, where the glyphs are 8x10 and laid
         out differently in the binary file.

   Version 0.11 (2012-Jul-28)
       * Kai Henningsen <kai.extern@gmail.com> discovered that 'Makefile'
         files generated by ucsdpsys_osmakgen did not correctly support the
         'distclean' target. This has been corrected.

       * Work is in progress to be able to cope with multiple p-machine
         versions.

       * The compiler is now able to cope with variables declared in plain
         units.

       * The ucsdpsys_osmakgen(1) command now understands how to generate the
         necessary debian/ files for building a debian package from the ucsd
         p-system operating system sources.

       * Thw ucsdpsys(1) file no longer creates the implied system disk image
         if one of the supplied disk images is a functioning system disk.

       * The ucsdpsys(1) command now better understands where ucsd-psystem-os
         installs its files, which it needs in order to build the default
         system disk image.

   Version 0.10 (2011-May-18)
       * A bug which caused a segfault in the ubsdpsys --batch option has been
         fixed.

       * The ucsdpsys_osmakgen(1) command, used by the ucsd-psystem-os project
         to generate its Makefile, now understands the presence of man pages,
         and installs them appropriately.

   Version 0.9 (2011-Feb-02)
       * The slides of the LCA 2011 talk "Factory Factory Factories" is now
         available in the web site.

       * The ucsdpsys_osmakgen(1) command has been improved, with a view to
         Debian packaging of the OS.

       * The ucsdpsys(1) command has a new --no-system option, to suppress the
         construction of a system disk image.

       * There is a new ucsdpsys_compile(1) option, --library-path for adding
         directories to the library search path.

       * The ucsdpsys_compile(1) command now fully supports the (*$U filename
         *) control comment.

       * The ucsdpsys_assemble(1) command now understands the .error .print
         .sbttl .title pseudo-ops, mostly named for PDP-11 assmebler pseudo-
         ops of the same name.

       * The ucsdpsys_charset(1) command has been moved to this project, out
         of the ucsd-psystem-fs project.

       * The ucsdpsys_assemble(1) command now understands how to produce
         assembler listings, using the -L option.  See ucsdpsys_assemble(1)
         for more information.

       * The ucsdpsys_compile(1) command now issues warnings for unreachange
         statements. There is a new (*$warning unreachable false *) control
         comment to disable the warning.

       * The project download web page now includes a link to the LunchPad
         PPA, where pre-compiled Ubuntu packages are available.

       * The ucsdpsys_assemble(1) command now understands the .ref pseudo-op,
         and generates the appropriate relocation information.

       * The ucsdpsys_assemble(1) command now more closely emulates the UCSD
         native assembler, in the way it forgets symbols created between one
         .proc and another.  This stops historical source files from
         complaining about multiply defined symbols all over the place.

       * The ucsdpsys_assemble(1) command now requires that the architecture
         be explicitly stated, either with the .arch pseudo-op, or the --arch
         command line option, in all cases.

       * The ucsdpsys_assemble(1) command now ignores all input after the .end
         directive.

       * The ucsdpsys_assembler(1) command now understands .gt greater than,
         >= greater than or equal, .lt less than, <= less than or equal, <>
         inequality, and = equality comparisons.

       * The ucsdpsys_assemble(1) command, now understands, for 6502 opcodes,
         how to relocate segment relative addresses for absolute addressing
         opcodes.

       * The ucsdpsys_assemble(1) command now understands conditional assembly
         .if, .else and .endc pseudo-op directives.

       * The ucsdpsys_assembler(1) command now understands the .macro pseudo-
         op, for defining an substituting macros into the code stream.

       * A bug has been fixed in the code that checks codefiles for validity.
         It no longer rejects segment dictionaries with zero-length UNITSEG
         segments.  These are produced when a program USES a non-intrinsic
         unit, but is not yet linked.

   Version 0.8 (2010-Aug-28)
       * The ucsdpsys_assemble(1) cross assembler now understands the .func
         pseudo-op.

       * The error message formatting has been changed to use a 4 character
         hanging indent for multi-line error messages.

       * A bug has been fixed in the ucsdpsys_osmakgen(1) command, it now
         correctly understands how to remove system segments from libraries
         with an assembler component.

       * The ucsdpsys_osmakgen(1) command now understands how to link Pascal
         programs with their assembler components.

       * A bug has been fixed in the ucsdpsys(1) command, it no longer fails
         if its temporary files are unlinked twice.

       * There is a new ucsdpsys_compile(1) --view-path option, symmetric with
         the ucsdpsys_assemble(1) and ucsdpsys_depends(1) commands' options of
         the same name.

       * The ucsdpsys_assemble(1) command now understands the .incude pseudo-
         op.  This is also a new corresponding -I command line option.

       * A bug has been fixed in the ucsdpsys_librarian(1) command, it now
         patches the segment number in the procedure dictionary when it
         renumbers a segment.

       * A bug has been fixed in the ucsdpsys_disassemble(1) and
         ucsdpsys_libmap(1) commands, they were printing SEPPROC link
         information incorrectly.

       * The ucsdpsys_osmakgen(1) command now generates an "install" target,
         so that the results of the build can be installed into the system.

       * The ucsdpsys_assemble(1) cross assembler now groks unary minus (-e)
         unary plus (+e) bit-wise and (e1 & e2), bit-wise or (e1 | e2), bit-
         wise not (~e), bit-wise exclusive-or (e1 ^ e2), and modulo (e1 % e2)
         expressions.

       * The ucsdpsys_compile(1) cross compiler can now cope with VAR clauses
         in the IMPLEMENTATION section of a UNIT.

       * The ucsdpsys_compile(1) cross compiler is now able to cope with units
         that export variables, noth intrinsic and non-intrinsic.

       * The ucsdpsys_compile(1) grammar now understands "var anything"
         parameters to external assembler procedures and functions.

       * The ucsdpsys_osmakgen(1) command now understands assembler source
         file include dependencies.

       * The ucsdpsys_depends(1) command now understands how to process
         assembler source files, when looking for include dependencies.

       * The ucsdpsys_assemble(1) command now procuces minimally correct
         relocation data sectiosn for each native code procedure.  The
         ucsdpsys_disassemble(1) command now has a minimally correct
         understanding of relocation data.

       * There is a new ucsdpsys_link(1) command, that may be used to link
         programs and libraries of separate procedures and functions together,
         to produce executable output codefiles.  See ucsdpsys_link(1) for
         more information.

       * The ucsdpsys_libmap(1) and ucsdpsys_disassemble(1) commands now
         include the EOFMARK link information record, to be sure it contains
         the correct argument.  The ucsdpsys_assemble(1) and
         ucsdpsys_compile(1) commands now correctly generate EOFMARK link
         information records.

       * The ucsdpsys_littoral(1) command now correctly translates nil to
         NULL.

       * The ucsdpsys_littoral(1) command now expands with variables
         completely.  This preserves the semantics into the C++ code.

       * There is now a build dependency on the libexplain project
         (http://libexplain.sourceforge.net/).

       * A bug has been fixed in the ucsdpsys(1) command, it no longer
         overwrite its own temporary files.  All of the ucsdpsys(1) options
         now have long versions as well.  The UCSD p-System volumes that are
         created on-the-fly are now created large enough to hold all of the
         data.

       * The ucsdpsys_osmakgen(1) command is now able to figure out when it
         needs to make a copy of system/globals.text based on include
         dependency information and the source file manifest.

       * The for statement now understands real control variables.  Note that
         the native compiler does not allow this.

       * The ucsdpsys_assemble(1) cross assembler now understands the .def
         pseudo-op.

   Version 0.7 (2010-Jun-21)
       * There is a new ucsdpsys_osmakgen(1) command, used to write the
         Makefile for the ucsd-psystem-os project.

       * The ucsdpsys_setup(1) command now accepts an --arch option, in order
         to select the byte sex of the SYSTEM.MISCINFO file it generates.

       * There is a new ucsdpsys_errors(1) command, to translating the
         assembler error files from text to binary.

       * The ucsdpsys_opcode(1) command now understands the opcode file format
         used by the UCSD Adaptive Assembler.

       * A bug has been fixed in the ucsdpsys_depends(1) command, it no longer
         writes to a file called "-" when it should write to the standard
         output.

       * The ucsdpsys_librarian(1) command has a new --remove-system-segments
         option, used to remove dummy segments from a (*$U-*) utility.

       * The ucsdpsys_librarian(1) command is now able to renumber segments
         when they are transferred bwtween codefiles.

       * The ucsdpsys_compile(1) command has a new --host option, that allows
         you to set the byte-sex based on the name of the host.  Which helps
         those of us who don't necessarily remember what endian-ness all of
         the hosts actually are.

       * The ucsdpsys_assemble(1) command has a new --architecture option, to
         permit the target architecture to be set from the command line.

       * The ucsdpsys_assemble(1) multi-target cross assembler now has the
         beginnings of support for PDP-11 assembler.

       * The cross compiler is now able to recognize the ord/odd hack (used to
         gain access to bit-wise opcodes) and turn such expression trees from
         logical operations into bit-wise operations.

       * The disassembler no longer rejects valid machine code segments with
         very short procedures.

       * The ucsdpsys_assemble(1) multi-target cross assembler now has
         beginnings of 6502 support, including both the MosTech syntax and the
         Apple syntax.

       * A bug has been fixed in the cross compiler, it now generates the
         correct opcode for the inline-math sqrt function.

       * The assembler now has a .radix pseudo-op, that may be used to change
         the default radix being used by the assembler.

       * A bug has been fixed in repeat/until statements, it was generating no
         code in some cases.

   Version 0.6 (2010-May-30)
       * The compiler now understands EXTERNAL function and procedure
         declarations, and produces corresponding linker records.

       * The compiler now has complete long integer support.

       * The compiler now understands the built-in STR function.

       * It is now possible to write long integer constants in the source
         code.  They take the same forms as other integer constants, except
         they are suffixed with the letter L.  This is an idea transplanted
         from C, the UCSD native compiler does not recognise such constants.
         It makes testing and debugging the long integer constant folding much
         easier.

       * The compiler now understands unit definitions, using II.1 syntax and
         semantics.  If II.0 separate unit definitions are seen, they result
         in a warning, and the separate keyword is otherwise ignored.

       * The compiler now understands a C-style ternary operator expression
         (e1 ? e2 : e3).  The UCSD native compiler doesn't have this.

   Version 0.5 (2010-May-17)
       * There is a new (*$feature underscore-significant true*) contol
         comment, that may be used for increased ISO 10206 conformance.

       * A bug has been fixed in the RECORD code, it no longer places the
         selector variable in the variant part of the record, and thus is no
         longer requesting memory from NEW that is one word short.

       * There is a new (*$feature efj-nfj false*) control comment to turn off
         the use of the EFJ and NFJ opcodes.

       * There is a new (*$feature short-with false*) control comment, that
         can be used to turn off WITH statement optimizations.

       * The built-in UNITWRITE procedure now accepts string constants for the
         second parameter.  The UCSD native compiler did not allow this.
         Handy for debugging the system I/O procedures.

       * The compiler now optimizes IF stratements with GOTO clauses.  It now
         goes directly to the label from the condition, when possible, rather
         than using UJP in the individual clauses.

       * The IF statement now generates better code for the case where THEN is
         empty but ELSE is not.

       * The compiler now understands the ISO 10206 integer constants with an
         explicit radix.  This was not available in the UCSD native compiler,
         for obvious reasons.

       * The is a new ucsdpsys_setup(1) command, used to encode and decode the
         SYSTEM.MISCINFO file.

       * There is a new ucsdpsys_downcase(1) command, that may be used to
         convert identifiers in Pascal source code from upper case to lower
         case.

       * The compiler no longer has a problem with sets passed as parameters.
         The way sets are push onto the stack has been further optimized.

       * The compiler now understands how to optimize away MOVELEFT, MOVERIGHT
         and FILLCHAR with a constant zero or negative length.

       * A bug has been fixed in the IN operator, in the case where the set
         had a fixed size.

       * A bug has been fixed in the constant folding of string comparisons,
         it was getting relational comparisons (<, <=, >, >=) wrong, but
         equality comparisons (=, <>) right.

       * A bug has been fixed in the indexing of byte arrays (pointers) with
         enum types.  It no longer throws an assert.

       * The compiler now issues warnings for comments that are not ISO 7185
         comforming.

       * A bug has been fixed in the code generation of MOV opcodes, in the
         case where more than 127 words had to be moved.

       * The compiler now understands arctan (ISO 10206) as a synonym for
         atan, but only if (*$feature inline-math true*) is in effect.

       * The compiler now generates correct code for NOT logical expressions
         assigned to a boolean variable, or passed as a boolean parameter.

       * A bug has been fixed in the code that folds constant MPI (integer
         multiply) expressions.

       * A bug has been fixed in the optimization of integer subtraction.

       * A bug has been fixed in the optimization of the ADI (add integer)
         expression.

       * A bug has been fixed in the optimisation of the logical NOT
         expression.

       * The cross compiler now understands the bit-wise integer AND, OR and
         NOT expressions.

       * The compiler now generates LDB (load byte) and STB (store byte)
         instructions for packed arrays of 8-bit things, not just packed array
         of char.  This is the same behaviour as the UCSD native compiler.

       * There is a new ucsdpsys_librarian(1) -R option, that can be used to
         remove segments by name or by number.

   Version 0.4 (2010-May-06)
       * A bug has been fixed in the code generation for large set constants.

       * The CASE statement now understands negative case values.

       * The compiler now understands how to cast string constants into
         packed-array-of-char constants, when they are procedure and functions
         parameters.

       * The compiler now understands when a case control expression is a
         function call with no parameters.

       * The compiler now understands functions calls with no parameters on
         either side of the IN operator.

       * The compiler now generates the correct code for segment procedures
         that are declared forward.

       * The compiler now understands how to pass parameters that are records,
         by value.

       * The compiler now generates correct code for array parameters when
         they are passed by value.

       * A bug has been fixed in the READLN code generation, it no longer
         throws an assert.

       * The compiler no longer issues syntax errors when semicolons appear in
         questionable places in RECORD declarations.

       * The way symbol conflicts and shadows are calaculated has been
         changed, it was getting false positive on the conflict tests.

       * The compiler now understands passing a string as the first parameter
         to the FILLCHAR procedure.

       * The compiler now understands the unary plus operator.

       * The compiler now understands the built-in GET, GOTOXY, PAGE, PUT,
         SEEK, UNITSTATUS and UNITWAIT procedures.

       * There is a new (*$feature inline-math true*) control comment.  When
         this is enabled, the compiler now understands the built-in ATAN, COS,
         EXP, LN, LOG, SIN and SQRT functions.

       * There is a new ucsdpsys_assemble(1) command, that may be used to
         assemble machine code and p-code.  It isn't particularly capable, as
         yet, but it will become more so as work proceeds on the p-machine
         validation

       * The compiler now accepts for loops of char values where one or both
         limits are char constants.

       * The built-in FILLCHAR procedure now accepts its third paramater being
         an enumerated type. This is for backwards compatibility with the UCSD
         native compiler.

       * The compiler now understands how to index an array by a char value.
         Previously it was throwing an assert.

       * There is a new (*$feature ignore-undefined-segment-zero true *)
         option, that can be used to turn off checking for undefined forward
         declarations, when those symbols would be in segment zero.  This
         "feature" is used by system utilities.  All other cases of forward
         functions being undefined result in a fatal error; use EXTERNAL for
         procedures to be linked later.

       * The disassembler can now cope with broken pointers in a segment's
         procedure dictionary.  Usually undefined (external) procedures with
         have a zero (0) entry in the procedure table.

       * The string parameters length check is now a warning, rather than an
         error.  This is because the implicit copy at run-time will throw a
         run-time error of the string doesn't fit.

       * The compiler now accepts calls to the built-in EOF and EOLN functions
         with no parameters.

       * The code generation for empty set constant has been improved.  It no
         longer throws an assert.  The same assert revealed that empty sets as
         a function parameter was not correctly being cast to the appropriate
         type of set.

   Version 0.3 (2010-Apr-25)
       * A warning is now issued if a case statement contains an otherwise
         clause.  You can disable the warning by using the (*$warning
         otherwise false*) control comment.

       * The compile listing now includes the symbol table for each procedure
         and function.

       * A bug has been fixed in the code that derefereces pointers to
         strings.  It no longer tries to laod the whole string onto the stack.
         The compiler now understands how to deal with string-typed fields on
         the right hand side of dot (expr.name) expressions.

       * A bug has been fixed where function parameters that were the names of
         functions that had no parameters were not being called.

       * The compiler no longer issues duplicate label warnings. In some cases
         it was issuing warnings about unused labels twice.

       * The compiler now understands the built-in COPY, DELETE, EOF, EOLN,
         FILLCHAR, INSERT, POS, UNITBUSY and UNITCLEAR functions and
         procedures.

       * The compiler no loger throws an assert if a procedure in segment zero
         is EXIT()ed.

       * The compiler now correctly scopes enumerated constant definitions
         that are declared within the record scopes.

       * A bug has been fixed in the code that copied non-var string
         parameters into their local temporaries.

       * Thw compiler now understands how to perform a non-local function
         return assignment.

       * The compiler now also accepts an integer value as the third parameter
         of fillchar, even thouh it is documented to take a char value.

       * A bug has been fixed where constant negative array indexes would
         cause an assert to fail. It turned out that some optimizations were
         not checking the range of offsets, and creating invalid offsets.

       * The compiler now understands declaring and accessing arrays using
         multi dimension syntax.

       * A number of error messages concerning forward declared types have
         been improved; they are now earlier, and less cryptic.

       * A bug has been fixed in the code generation of constant sets.  They
         are no longer all-bits-zero, but instead contain the correct value.

       * The compiler now only range checks the CHR parameter if requested.
         The UCSD native compiler did not range check CHR.

       * The compiler now checks parameter string lengths (declared vs actual)
         for overruns.

       * The compiler now understands about file^ variables.

       * The ucsdpsys(1) command is now better at cleaning up its temporary
         files.

       * The boolean comparison operators (=, <>, <=, <, >=, >) now have
         additional code to cope with one side or the other being a constant.

       * A bug has been fixed in the way constant folding was handled around
         the FOR statement's limits.

   Version 0.2 (2010-Apr-19)
       * The target for this release was to be able to compile the UCSD native
         Pascal compiler from source.  This has been achieved.  It has yet to
         be determined if the compiler thus created actually functions.

       * For differences between this cross compiler and the UCSD native
         compiler, see the ucsdpsys_compile(1) man page.  The most notable
         difference is that SIZEOF is a keyword, requiring the UCSD native
         compiler's PROCEDURE SIZEOF to be renamed.

       * Numerous bugs have been fixed, usually in unexplored corner cases.

       * The compiler now understands the ABS, BLOCKREAD, BLOCKWRITE, CLOSE,
         CONCAT, EXIT, HALT, IDSEARCH, IORESULT, KEYBOARD, LENGTH, MARK, MOD,
         MOVELEFT, MOVERIGHT, OPENNEW, OPENOLD, PWROFTEN, READ, READLN,
         RELEASE, RESET, REWRITE, ROUND, SCAN, TREESEARCH, TRUNC, UNITREAD,
         UNITWRITE and WRITELN built-in symbols.

       * The STRING type has been turned into a built-in named type.  This
         permits the unwise user to redefine STRING to be a variable or a
         procedure or a function, or (for maximum confusion) a different type.
         This is what shadow warnings are for.

       * The compiler now understands the CASE, FOR, REPEAT UNTIL and WITH
         statements.

       * The compiler now understands comparisons of CHAR values.

       * The compiler now accepts pointers as parameters to the ORD function.
         This seems oddly inconsistent, in a language as intent as Pascal is,
         with the protection of the programmer from his own folly.

       * The compiler now understands set arithmetic and set comparisons.

       * It is now possible, using the ucsdpsys_compile --listing option, to
         obtain a compiler listing.  The listing contains the source code
         interleaved with the disassembled p-code.  The (*$L) control comment
         is ignored.

       * The compiler now understands = and <> comparisons of multi-word
         values (arrays and records).

       * The compiler can now be configured to have longer identifier (name)
         lengths.  It defaults to 8 for compatibility, and it still drops
         underscores.

       * The compiler now understands comparisons of packed arrays of char.

   Version 0.1 (2010-Apr-01)
       First public release.

       * The following built-in functions are understood: CHR, MEMAVAIL, ODD,
         ORD, PRED, SIZEOF, SQR, SUCC, TIME.

       * All of the usual Pascal expresion operators are understood, although
         not always across the full range of parameter types.

       * The cross compiler can produce both little-endian codefiles and big-
         endian codefiles.

       * A number of features from modern Pascal implementations are avilable:
         hex constants, binary constants, short-circuit boolean evaluation,
         the address-of (@) operator,

       * Most of the Pascal statement types are available, including: BEGIN
         END, CASE (and OTHERWISE), FOR, GOTO (local), IF THEN (ELSE), NEW
         (including variant types), REPEAT UNTIL, WHILE, WITH, WRITE, WRITELN.
         It is not yet possble to use non-local GOTO.

       * Segment procedures can be created, and UNIT interfaces can be
         accessed from library codefiles.  It is not yet possible to compile
         UNITs.  While FORWARD procedures and functions are understood,
         EXTERNAL procedures and functions are not yet supported.

       * All of the UCSD Pascal data types are supported: ARRAY (including
         PACKED ARRAY), BOOLEAN, CHAR, enumerated, FILE, INTEGER INTERACTIVE,
         pointers, REAL, RECORD (including PACKED RECORD), SET, STRING
         (including STRING[n]), subrange, TEXT.  The long integer types are
         not yet supported.

       * The cross compiler understands many of the UCSD Pascal constants,
         including: FALSE, MAXINT, NIL, TRUE,

       * The cross compiler is able to optimize most statements and
         expressions better than the Apple Pascal native compiler.  Constant
         expressions are folded at compile time.

       * There is a ucsdpsys_depends(1) command, that can be used by your
         build system to scan for (*$I filename*) include directives.

   Version 0.0 (2006-May-22)
       No public release.



Reference Manual                ucsd-psystem-xc       Read Me(ucsd-psystem-xc)