<preface>
<title>Differences between Versions 1.1 and 1.0</title>
<caution>
<title>Important Notice - Please Read Carefully</title>
<para>
This package contains the OS-9 C Compiler Version 1.1. Many
improvements and bug fixes have been incorporated since the V1.0
release. If you are upgrading from V1.0, be <emphasis>absolutely sure</emphasis>
to all <emphasis>all</emphasis> the files from the V1.1 disks. None of the
compiler sections or the library is compatible with V1.0 files. Any ".r" or
".a" files produced by the V1.0 compiler should not be assembled or
linked with any ".a" or ".r" files produced by the V1.1 compiler.
To be safe, recompile/reassemble <emphasis>all</emphasis> ".a" and ".r"
files with V.1.1.
</para>
<para>
This update include appendices for the C Compiler User's Guide
describing the compiler error messages, compiler phase command
lines, interfacing C functions to BASIC09, and an overview of the
relocating macro assembler.
</para>
<para>
The remainder of this notice describes the changes made since V1.0.
</para>
</caution>

<variablelist>
<varlistentry><term>General:</term>
<listitem>
<para>
The compiler code generator and c.opt have been improved to
produce even smaller object code. This, and improved source
coding, has resulted in a 1 page decrease in the size of c.comp
and a 4 page decrease in c.pass1.
</para>
</listitem>
</varlistentry>

<varlistentry><term>Executives (cc1 and cc2):</term>
<listitem>
<para>
-x appearing on the cc1 command line causes the compiler to
make the c.com command file but not execute it. -q on the cc2
command line causes the compiler to suppress filename and
compiler phase messages.
</para>
</listitem>
</varlistentry>

<varlistentry><term>Preprocessor (c.prep):</term>
<listitem>
<para>
C.prep now prints a fatal error if a line exceeds 255 bytes.
</para>
</listitem>
</varlistentry>

<varlistentry><term>Compiler (c.comp, c.pass1, c.pass2):</term>
<listitem>
<para>
C.pass1 float/double conversion is now done properly rather
than reporting error 7.
</para>
<para>
Direct and static direct storage classes may now be
initialized.
</para>
<para>
Sizeof operator now reports an error when applied to an
undefined identifier. Sizeof now allows any expression inside
of parenthesis. Previously, only primaries were allowed.
</para>
<para>
Various code generation problems involving certain long and
floating operations have been fixed.
</para>
</listitem>
</varlistentry>

<varlistentry><term>Optimizer (c.opt):</term>
<listitem>
<para>
C.opt has been improved to use much less dynamic memory while
performing optimizations.
</para>
<para>
Some branches were erroneously converted to short branches
when they should have been long.
</para>
</listitem>
</varlistentry>

<varlistentry><term>Assembler (c.asm):</term>
<listitem>
<para>
C.asm can now handle direct-page initialized data.
</para>
<para>
Some out-of-range short branches were not detected.
</para>
<para>
VSECT syntax changed to allow direct-page initializers. This
make V1.0 assembly file incompatible with V1.1.
</para>
<para>
Macro and repeat block facilities have been added.
</para>
</listitem>
</varlistentry>

<varlistentry><term>Linker (c.link):</term>
<listitem><para>
C.link can now handle direct-page initialized data.
</para>
<para>
C.link will now report if the direct page allocations exceeds 256 bytes.
</para>
<para>
C.link is about three times faster using the improved V1.1 standard library.
</para>
<para>
C.link can now output modules that can be entered by the BASIC09 "RUN" command.
</para>
</listitem>
</varlistentry>

<varlistentry><term>Library (clib.l):</term>
<listitem><para>
The standard library FILE structure has been changed to allow
specification of buffersize for a file. In V1.0, the
buffersize was fixed at 256 bytes. A new element of the FILE
struct (_bufsiz) contains the desired buffer size. This may be
used as follows:
<programlisting>
main()
{
     FILE *fp;

     fp=fopen("file","r");
     fp->_bufsiz = 1024;

.....
}
</programlisting>
A few restrictions exist on the use of this parameter.
Initially the _bufsiz value is 0. The library routines will
assign a buffer of 256 bytes to the file upon initial read
or write. If the value is non-zero and the fp has not
previously been accessed, that value is used as the
buffersize. Note that due to the way the library routines
work, once a buffer of a given size is allocated to an fp, a
larger size cannot be used, even if the file is closed. Note
that the buffers are allocated from the ibrk() so enough extra
memory must be allocated by the linker to handle the bigger
buffers.
</para>
<para>
Since the size of the _iobuf struct (FILE) in stdio.h has
changed, all .r files must be re-compiled using the new header
file.
</para>
<para>
Cstart.r can now handle direct page data initialization.
</para>
<para>
Fseek() now does not cause the buffer to be re-filled if the
seek destination is already in the buffer.
</para>
<para>
Getc() now does "I$READ" on unbuffered SCF devices rather than
"I$READLN".
</para>
<para>
Getc() performed on "stdin" flushes the "stdout" buffer.
</para>
<para>
Printf() has been changed to not flush the "stdout" buffer
before returning.
</para>
<para>
Chown() has been fixed to not wipe out disks.
</para>
<para>
Toascii() has been added to stdio.h
</para>
<para>
Calls to scanf() now do not cause the linker to reports
unresolved references to toupper() and tolower().
</para>
<para>
The floating point routines now report errors 40, 41, and 42
for floating point over/underflow, divide by zero, and
float/long conversion instead of error #007.
</para>
</listitem>
</varlistentry>

</variablelist>
</preface>