Notes on the MSDOS implementation of dmake.

Bootstrapping the binary:
-------------------------
   A make.bat file is provided to bootstrap the binary.  The file contains
   several targets for bootstrapping.  Invoking the batch file with no
   arguments lists the possibilities shown below.

      INDEX:  You must specify one of:
	 tcc      - Turbo C 2.0 compile.
	 tccswp   - Turbo C 2.0 compile of swapping dmake.
	 bcc      - Borland C++ 2.0 compile.
	 bccswp   - Borland C++ 2.0 compile of swapping dmake.
	 msc40    - Microsoft C 4.0 compile.
	 msc50    - Microsoft C 5.0 compile.
	 msc51    - Microsoft C 5.1 compile.
	 msc60    - Microsoft C 6.0 compile.
	 msc40swp - Microsoft C 4.0, MASM 5.1 compile of swapping dmake.
	 msc50swp - Microsoft C 5.0, MASM 5.1 compile of swapping dmake.
	 msc51swp - Microsoft C 5.1, MASM 5.1 compile of swapping dmake.
	 msc60swp - Microsoft C 6.0, MASM 5.1 compile of swapping dmake.
	 ztc      - Zortech C++ 2.1 compile.
	 ztcswp   - Zortech C++ 2.1 compile of swapping dmake.

   Based on the compiler you have installed and whether or not you
   want the swapping version of dmake, you should select the appropriate
   target and issue 'make.bat target'.

   The batch file runs a second batch script that comes with the distribution
   which compiles the sources using the appropriate compiler and flags.  The
   MSC Versions of the batch files should not require any further user
   intervention during the compile.  The Turbo-C version, as a final step,
   invokes tlink with two response files.  The second of these response files,
   named in msdos/tccdos/mk*.bat, contains absolute path names to Turbo-C
   libraries.  You may need to edit these before getting a successful binary
   linked.

   By default the batch files make an executable that will run on an 8088
   cpu and up.  You can change that by making the initial version and then
   editing the config.mk files found in either msdos/tccdos or msdos/mscdos
   (depending on the compiler you use), and selecting a diferrent cpu type by
   supplying the appropriate compiler flags.  You then need to remake dmake
   again but this time use dmake itself, see below.

   Note that the file msdos/exec.uue is a uuencoded version of a BCC++
   compiled exec.obj (from exec.asm).  If you do not have an assembler
   either microsoft MASM or Borland TASM (or some other), you can uudecode
   this file and put it into the appropriate objects directory.


Using dmake to Make itself:
---------------------------
   If you use dmake to make itself you must first set a number of makefile
   control variables, either through the environment or on the command line.

   The following variables must be set:

	OS	       - defines operating system (must be set)
	OSRELEASE      - particular version of it.
	OSENVIRNOMENT  - more customization

   These three variables should be defined in your environment.  Valid values
   for them are listed in the readme/options file.  For example, if you
   are using MSDOS, with Turbo-C then the valid settings are:

	set OS=msdos
	set OSRELEASE=tccdos
	set OSENVIRONMENT=

   dmake searches for an initial startup file, you should set the environment
   variable MAKESTARTUP to contain the full path to the startup file, eg:

	set MAKESTARTUP=d:\usr\lib\startup.mk

   The dmake makefile has several variables that can be user specified and
   default to reasonable values if not set.

	MODEL   - defines the model to compile, valid values are
		  {s,c,m, or l}, defaults to 'l' (ie. large) model
		  if unspecified.

	MSC_VER - defines the version of Microsoft C in use, should be set to
		  one of 4.0, 5.0, 5.1 or 6.0; defaults to 6.0.

	SWAP    - If set to 'y', compile the dmake swapping version of
		  spawnvpe.  This has the effect of turning on swapping of the
		  executable to disk if the MSDOS version is made.

	DEBUG   - If set to '1' then make the debugging version of dmake, this
		  will also set MODEL to 'l'.

   To set the above variables you must specify them on the dmake command line
   or insert them into the makefile.mk definition.


Memory Requirements and Swapping:
---------------------------------
   The swapping code currently only swaps to DISK, I have left hooks
   in to accomodate XMS and EMS, I have some code that performs the
   necessary XMS/EMS accesses but have not incorporated it in yet.
   It appears that a ramdisk seems to work just fine.  If anyone
   wishes to fill in the hooks please do and I'll be happy to include
   them in future distributions.


^C and stopping a make:
-----------------------
   Thanks to the efforts of Len Reed, appears to now work.  I have been unable
   to hang my machine if it's swapped out and I hit ^C a couple thousand times.


Other notes:
------------
   dmake does not care if you are running command.com or some other command
   interpretter, you must however specify the proper values of the environment
   variables SHELL, SHELLFLAGS, GROUPSHELL, and GROUPFLAGS in order for things
   to work correctly.  Read the man page FIRST, if you still have trouble
   then send email.

   Group recipes under DOS that use command.com as the command interpretter
   require you to set the GROUPSUFFIX macro.

   As shipped the startup.mk files for the DOS version try to figure out what
   command interpretter you are using and set things up appropriately.
   Two command interpretters are supported in the shipped startup.mk file,
   command.com, and the MKS Korn shell.

   dmake does not contain any builtin commands.  It gets all commands it
   executes from an external file system.  It is therefore most useful if it
   is used in conjunction with an environment similar to that provided by
   the MKS Tool Kit, or equivalent.

   dmake now supports the MKS argument passing conventions.  The facility is
   enabled by setting .MKSARGS:=1.  It is set by default in the startup.mk file
   if an MKS Korn shell is detected as being the active command interpretter.