1/19/94

Dear Reader,

This is a printout of the most salient portions of the README.NOW file 
on your distribution disk.  The code on the  disk is for Second Edition 
of The C Programmer's Guide to Serial Communication.  I'm sorry to report 
that a rushed production schedule at the publisher resulted in a First 
Printing with an unacceptable number of errors.  At my request, remaining 
copies of this printing are being removed from the shelves.  The 
corrected Second Printing ought to be available about February 1, 1994. 
Owners of the First Printing of the Second Edition may obtain a free 
copy of the Second Printing by contacting Jordan Gold at (317) 581-3669 
(Compuserve 71075,446).  If you have any problems obtaining a replacement, 
please let me know. 

This disk also works for the First Edition.  A few functions have changed 
and I've taken a few new approaches.  In general, the new edition contains
chapters and code for advanced interrupts, facsimile, and protocol modems.
 
I make improvements to the code more or less continually, so you'll
quickly discover minor undocumented discrepancies between the book's
code and the code on this disk.  You'll also discover that I've left
in place many of my debugging aids that were removed for publication.
Lines containing the odd-looking comment "" or lines beginning
with "//" identify debugging lines. 

Now, here's how you use this disk:

1.  You'll need about 1.2M to hold the source; 2.1+M to hold the source, 
    obj's, and libraries. I developed under Microsoft 6.00A, but have 
    verified (quickly) under 7.0. All source compiles at Warning Level 3 
    with no warnings.  The NMAKE files assume that LIB.EXE, LINK.EXE, 
    and MASM.EXE are in the path, but I've included the assembly language
    .LIB and OBJ files just in case you don't own MASM.  

2.  The code is distributed in a self-extracting archive, CPGSC.EXE.

3.  Log into the root directory on the drive where you wish to install 
    the code. Insert the disk into a floppy and type:

                         CPGSC -d  x:

     where x is the drive where you want to install it. DON'T FORGET THE "-D"!

4.  De-archiving creates a copy of my development directory structure
    on the specified drive:

                x:\ <------------------your drive id
                |--!PG
                |  +--SIO
                |  |    +--ASM
                |  |        +--OBJS
                |  |    +--BUOS
                |  |        +--OBJS
                |  |    +--CRC
                |  |        +--OBJS
                |  |    +--FAX
                |  |        +--OBJS
                |  |    +--IBMPC
                |  |        +--OBJS
                |  |    +--MISC
                |  |        +--OBJS
                |  |    +--MODEM
                |  |        +--OBJS
                |  |    +--PROGS
                |  |
                |  |    +--TERMFUNC
                |  |        +--OBJS
                |  |    +--U16X50
                |  |        +--OBJS
                |  |    +--XMODEM
                |  |        +--OBJS
                |  |    +--_SIO
                |  |        +--OBJS
                +--COMPILER
                    +--INCLUDE
                        +--SIO

5.  The directory \COMPILER\INCLUDE\SIO contains the INCLUDE files for my
    code.  Create a new directory named SIO under your compiler's INCLUDE
    directory. Copy these .H files to it. After this copy you may erase
    the entire \COMPILER subdirectory.

6.  In each directory you will see DIRNAME.NMK.  These are input files for
    Microsoft's NMAKE utility.

7.  Included are  batch files REBUILD.BAT (builds the entire library
    from scratch) and BUILD.BAT, which just runs the make file in each
    subdirectory.

8.  If you've changed any of the path names from those shown on the
    tree above, CD to the PROGS directory and edit the paths in PROGS.RSP,
    the linker response file. 

9.  The NMAKE files require the following variables in your environment:

          LIB  This is the variable used by your compiler for libraries. 

      INCLUDE  This is the variable used by your compiler for include files.
               (I assume this one's already present.)

     SIO_BASE The base subdirectory for the C source:
                         
                           x:\!PG\SIO

              where 'x' is the drive you want to install  on.


SIO_INC_PATH  This is the subdirectory for this project's includes. 
              The source code assumes that the includes are under
              INCLUDE, but I've provided a NMAKE variable for future
              flexibility.
          CL  Environment arguments for the compiler:

                  /AS  Desired Model
                  /W   NMAKE quits on compiler warnings

               You may wish to use the /Zid (Add Codeview information 
               and line numbers), but be aware that this may cause the
               compiler to die with the message "Compiler out of 
               far heap space."  In other words, you need to have 
               lots of memory available at the DOS prompt.

10.  Assuming you've got all the environment variables installed, CD
     to \!pg\sio and type

                   REBUILD  

11. The batch file compiles all the source, creates the libraries, and 
    links the TERM7 program from the book.  TERM7 will be about 70K.  It
    will be a whopper if compiled with the /Zid option and linked with the
    /CO option. If you wish to remove Codeview info from your OBJ's, just 
    delete the /CO from TERM7.RSP.

12. Now that you've carefully read everything in this file and BEFORE 
    running the batch file:

                  DEL \!PG\TRAPDOOR.BAT

13. To compile Large MODEL:

      A.   Change /AS to /AL in the CL environment variable.

      B.  Change the model defined in ASM.NMK. In case you don't
          have MASM, both LIBs are provided, ASMS.LIB (Small)
          and ASML.LIB (Large). Copy the desired model library to ASM.LIB.

14. By default, the files BUILD.BAT and REBUILD.BAT have the NMAKE
    commands for the ASM directory REM'ed out.  If you own MASM and wish
    to modify the assembler, remove the REM statements.  Model control
    is via the /DSMALLMODEL to /DLARGEMODEL directives in ASM.NMK.

15. The TERM7 program defaults to COM3.  To override, enter the
    ordinal number of the port you desire (i.e., COM1 is 0).

16. If you're developing applications that must run in a Windows 
    3.x DOS box, you won't be able to use the 16550 ISR shown in the
    book.  Although Windows does not support the 16550, many software
    packages provide serial drivers that do.  Alas, all I have seen 
    treat the 16550 TIMEOUT interrupt correctly.  For this reason, you'll
    find that s_open doesn't not use the 16550 ISR. 

17. Read the file NEWSIO.DOC in the IBMPC directory for instructions
    on how to automate changes to the COMxSIO.C files.