diff --git a/build.bat b/build.bat
index e18eb19..c35eb1f 100644
--- a/build.bat
+++ b/build.bat
@@ -1,21 +1,30 @@
 @echo off
+rem batch file to build everything
 rem IF NOTHING COMPILES, CHECK IF YOUR CVS CHECKOUT USES CORRECT DOS LINEBREAKS
 
-:- batch file to build everything
-:- $Id$
+if NOT "%1" == "/?" goto start
+echo ":-----------------------------------------------------------------------"
+echo ":- Syntax: BUILD [-r] [fat32|fat16] [msc|wc|tc|tcpp|bc] [86|186|386]    "
+echo ":-               [debug] [lfnapi] [/L #] [/D value] [list] [upx] [win]  "
+echo ":- option case is significant !!                                        "
+echo ":- Note: Open Watcom (wc) is the preferred compiler                     "
+echo ":-----------------------------------------------------------------------"
+goto end
 
-:- Syntax: BUILD [-r] [fat32|fat16] [msc|wc|tc|tcpp] [86|186|386]
-:- option case is significant !!
+:start
+
+:- assume an error until successful build
+set XERROR=1
+if "%XERROR%" == "" goto noenv
 
 if "%1" == "-r" call clobber.bat
 if "%1" == "-r" shift
 
-set XERROR=
-
 if not exist config.bat echo You must copy CONFIG.B to CONFIG.BAT and edit it to reflect your setup!
 if not exist config.bat goto abort
 
 call config.bat
+:-if "%LAST%" == "" goto noenv
 set dos4g=quiet
 
 :-----------------------------------------------------------------------
@@ -32,11 +41,27 @@ if "%1" == "msc"   set COMPILER=MSCL8
 if "%1" == "wc"    set COMPILER=WATCOM
 if "%1" == "tc"    set COMPILER=TC2
 if "%1" == "tcpp"  set COMPILER=TURBOCPP
+if "%1" == "bc"    set COMPILER=BC
 
 if "%1" == "86"    set XCPU=86
 if "%1" == "186"   set XCPU=186
 if "%1" == "386"   set XCPU=386
+if "%1" == "x86"   goto setCPU
 
+if "%1" == "upx"   set XUPX=upx --8086 --best
+
+if "%1" == "debug" set ALLCFLAGS=%ALLCFLAGS% -DDEBUG
+if "%1" == "lfnapi" set ALLCFLAGS=%ALLCFLAGS% -DWITHLFNAPI
+
+if "%1" == "win"   set ALLCFLAGS=%ALLCFLAGS% -DWIN31SUPPORT
+if "%1" == "win"   set NASMFLAGS=%NASMFLAGS% -DWIN31SUPPORT
+
+if "%1" == "list"  set NASMFLAGS=%NASMFLAGS% -l$*.lst
+
+if "%1" == "/L"    goto setLoadSeg
+if "%1" == "/D"    goto setDefine
+
+:nextOption
 shift
 if not "%1" == "" goto loop_commandline
 
@@ -44,11 +69,14 @@ if "%COMPILER%" == "" echo you MUST define a COMPILER variable in CONFIG.BAT
 if "%COMPILER%" == "" goto abort
 
 call default.bat
+:-if "%LAST%" == "" goto noenv
 
 :-----------------------------------------------------------------------
 :- finally - we are going to compile
 :-----------------------------------------------------------------------
 
+echo USING OPTIONS of C=[%ALLCFLAGS%] ASM=[%NASMFLAGS%]
+
 echo.
 echo Process UTILS ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 echo.
@@ -83,6 +111,7 @@ echo.
 cd ..\sys
 %MAKE% production
 if errorlevel 1 goto abort-cd
+if NOT "%XUPX%" == "" %XUPX% ..\bin\sys.com
 
 echo.
 echo Process KERNEL +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
@@ -93,10 +122,10 @@ if errorlevel 1 goto abort-cd
 
 cd ..
 
-:- if you like, put some finalizing commands (like copy to floppy)
-:- into build2.bat
+set XERROR=
 
-if exist build2.bat call build2
+:- if you like, put finalizing commands (like copy to floppy) into build2.bat
+if exist build2.bat call build2.bat
 
 echo.
 echo Processing is done.
@@ -104,11 +133,49 @@ goto end
 
 :-----------------------------------------------------------------------
 
+:setLoadSeg
+shift
+if "%1" == "" echo you MUST specify load segment eg 0x60 with /L option
+if "%1" == "" goto abort
+set LOADSEG=%1
+goto nextOption
+
+:setCPU
+shift
+if "%1" == "" echo you MUST specify compiler's cpu cmd line argument, eg -5
+if "%1" == "" goto abort
+set XCPU_EX=%1
+goto nextOption
+
+:setDefine
+shift
+:- Give extra compiler DEFINE flags here
+if "%1" == "" echo you MUST specify value to define with /D option
+if "%1" == "" echo such as /D DEBUG : extra DEBUG output
+if "%1" == "" echo or      /D DOSEMU : printf output goes to dosemu log
+if "%1" == "" echo or      /D WIN31SUPPORT : enable Win 3.x hooks
+if "%1" == "" goto abort
+if "%2" == "/V" goto :setDefineWithValue
+set ALLCFLAGS=%ALLCFLAGS% -D%1
+set NASMFLAGS=%NASMFLAGS% -D%1
+goto nextOption
+
+:setDefineWithValue
+set ALLCFLAGS=%ALLCFLAGS% -D%1=%3
+set NASMFLAGS=%NASMFLAGS% -D%1=%3
+shift
+shift
+goto nextOption
+
+:noenv
+echo Unable to set necessary environment variables!
+goto abort
+
 :abort-cd
 cd ..
+
 :abort
 echo Compilation was aborted!
-set XERROR=1
 
 :end
-default.bat clearset
+call default.bat clearset