diff --git a/README.md b/README.md
index 4ccc6369..4eb76119 100644
--- a/README.md
+++ b/README.md
@@ -374,6 +374,27 @@ See the 0readme_ethernet.txt file for details about the required network compone
 
 The makefile provided requires GNU make, which is the default make facility for most systems these days.  Any host system which doesn't have GNU make available as the default make facility may have it installed as 'gmake'.  GNU make (gmake) is generally available an installation package for all current operating systems which have a package installation system.
 
+##### Build Dependencies
+
+Some simulators depend on external packages to provide the full scope of functionality they may be simulating.  These additional external packages may or may not be included in as part of the standard Operating System distributions.  
+
+###### OS X - Dependencies
+
+The MacPorts package manager is available to provide these external packages.  Once MacPorts is installed, these commands will install the required dependent packages:
+
+    # port install vde2
+    # port install libsdl2
+
+###### Linux - Dependencies
+
+Different Linux distributions have different package managment systems:
+
+Ubuntu:
+
+    # apt-get install libpcap-dev
+    # apt-get install vde2
+    # apt-get install libsdl2
+
 #### Windows
 
 Compiling on windows is supported with recent versions of Microsoft Visual Studio (Standard or Express) and using GCC via the MinGW environment.  Things may also work under Cygwin, but that is not the preferred windows environment.  Not all features will be available as well as with either Visual Studio or MinGW.
diff --git a/doc/simh_doc.doc b/doc/simh_doc.doc
index eddc06a7..3e6217bf 100644
Binary files a/doc/simh_doc.doc and b/doc/simh_doc.doc differ
diff --git a/makefile b/makefile
index 2d6b501a..4de65dd4 100644
--- a/makefile
+++ b/makefile
@@ -35,9 +35,22 @@
 # If debugging is desired, then GNU make can be invoked with
 # DEBUG=1 on the command line.
 #
-# OSX and other environments may have the LLVM (clang) compiler 
-# installed.  If you want to build with the clang compiler, invoke
-# make with GCC=clang.
+# simh project support is provided for simulators that are built with 
+# dependent packages provided with the or by the operating system 
+# distribution OR for platforms where that isn't directly available (OS X) 
+# by packages from specific package management systems (MacPorts).  Users 
+# wanting to build simulators with locally build dependent packages or 
+# packages provided by an unsupported package management system can 
+# override where this procedure looks for include files and/or libraries.  
+# Overrides can be specified by define exported environment variables or 
+# GNU make command line arguments which specify INCLUDES and/or LIBRARIES.  
+# Each of these, if specified, must be the complete list include directories
+# or library directories that should be used with each element separated by 
+# colons. (i.e. INCLUDES=/usr/include/:/usr/local/include/:...)
+#
+# Some environments may have the LLVM (clang) compiler installed as
+# an alternate to gcc.  If you want to build with the clang compiler, 
+# invoke make with GCC=clang.
 #
 # Internal ROM support can be disabled if GNU make is invoked with
 # DONT_USE_ROMS=1 on the command line.
@@ -84,6 +97,7 @@ else
     BESM6_BUILD = true
   endif
 endif
+find_exe = $(abspath $(strip $(firstword $(foreach dir,$(strip $(subst :, ,$(PATH))),$(wildcard $(dir)/$(1))))))
 find_lib = $(abspath $(strip $(firstword $(foreach dir,$(strip $(LIBPATH)),$(wildcard $(dir)/lib$(1).$(LIBEXT))))))
 find_include = $(abspath $(strip $(firstword $(foreach dir,$(strip $(INCPATH)),$(wildcard $(dir)/$(1).h)))))
 ifneq ($(findstring Windows,$(OS)),)
@@ -174,17 +188,41 @@ ifeq ($(WIN32),)  #*nix Environments (&& cygwin)
     endif
     OS_LDFLAGS = -lm
   else # Non-Android Builds
-    INCPATH:=/usr/include
-    LIBPATH:=/usr/lib
+    ifeq (,$(INCLUDES)$(LIBRARIES))
+      INCPATH:=/usr/include
+      LIBPATH:=/usr/lib
+    else
+      $(info *** Warning ***)
+      ifeq (,$(INCLUDES))
+        INCPATH:=$(shell LANG=C; $(GCC) -x c -v -E /dev/null 2>&1 | grep -A 10 '> search starts here' | grep '^ ' | tr -d '\n')
+      else
+        $(info *** Warning *** Unsupported build with INCLUDES defined as: $(INCLUDES))
+        INCPATH:=$(strip $(subst :, ,$(INCLUDES)))
+        UNSUPPORTED_BUILD := include
+      endif
+      ifeq (,$(LIBRARIES))
+        LIBPATH:=/usr/lib
+      else
+        $(info *** Warning *** Unsupported build with LIBRARIES defined as: $(LIBRARIES))
+        LIBPATH:=$(strip $(subst :, ,$(LIBRARIES)))
+        ifeq (include,$(UNSUPPORTED_BUILD))
+          UNSUPPORTED_BUILD := include+lib
+        else
+          UNSUPPORTED_BUILD := lib
+        endif
+      endif
+      $(info *** Warning ***)
+    endif
     OS_CCDEFS = -D_GNU_SOURCE
     GCC_OPTIMIZERS_CMD = $(GCC) -v --help 2>&1
     GCC_WARNINGS_CMD = $(GCC) -v --help 2>&1
     LD_ELF = $(shell echo | $(GCC) -E -dM - | grep __ELF__)
-    INCPATH:=$(shell LANG=C; $(GCC) -x c -v -E /dev/null 2>&1 | grep -A 10 '> search starts here' | grep '^ ' | tr -d '\n')
     ifeq (Darwin,$(OSTYPE))
       OSNAME = OSX
       LIBEXT = dylib
-      INCPATH:=$(shell LANG=C; $(GCC) -x c -v -E /dev/null 2>&1 | grep -A 10 '> search starts here' | grep '^ ' | grep -v 'framework directory' | tr -d '\n')
+      ifneq (include,$(findstring include,$(UNSUPPORTED_BUILD)))
+        INCPATH:=$(shell LANG=C; $(GCC) -x c -v -E /dev/null 2>&1 | grep -A 10 '> search starts here' | grep '^ ' | grep -v 'framework directory' | tr -d '\n')
+      endif
       ifeq (incopt,$(shell if $(TEST) -d /opt/local/include; then echo incopt; fi))
         INCPATH += /opt/local/include
         OS_CCDEFS += -I/opt/local/include
@@ -199,12 +237,16 @@ ifeq ($(WIN32),)  #*nix Environments (&& cygwin)
       endif
     else
       ifeq (Linux,$(OSTYPE))
-        LIBPATH := $(sort $(foreach lib,$(shell /sbin/ldconfig -p | grep ' => /' | sed 's/^.* => //'),$(dir $(lib))))
+        ifneq (lib,$(findstring lib,$(UNSUPPORTED_BUILD)))
+          LIBPATH := $(sort $(foreach lib,$(shell /sbin/ldconfig -p | grep ' => /' | sed 's/^.* => //'),$(dir $(lib))))
+        endif
         LIBEXT = so
       else
         ifeq (SunOS,$(OSTYPE))
           OSNAME = Solaris
-          LIBPATH := $(shell LANG=C; crle | grep 'Default Library Path' | awk '{ print $$5 }' | sed 's/:/ /g')
+          ifneq (lib,$(findstring lib,$(UNSUPPORTED_BUILD)))
+            LIBPATH := $(shell LANG=C; crle | grep 'Default Library Path' | awk '{ print $$5 }' | sed 's/:/ /g')
+          endif
           LIBEXT = so
           OS_LDFLAGS += -lsocket -lnsl
           ifeq (incsfw,$(shell if $(TEST) -d /opt/sfw/include; then echo incsfw; fi))
@@ -458,9 +500,24 @@ ifeq ($(WIN32),)  #*nix Environments (&& cygwin)
       $(info *** Info ***)
       $(info *** Info *** The simulator$(BUILD_MULTIPLE) you are building could provide more)
       $(info *** Info *** functionality if video support were available on your system.)
-      $(info *** Info *** Install the development components of libSDL packaged by your)
-      $(info *** Info *** operating system distribution and rebuild your simulator to)
-      $(info *** Info *** enable this extra functionality.)
+      ifeq (Darwin,$(OSTYPE))
+        $(info *** Info *** Install the MacPorts libSDL2 packaged to provide this)
+        $(info *** Info *** functionality for your OS X system:)
+        $(info *** Info ***       # port install libsdl2)
+	  else
+        ifneq (,$(and $(findstring Linux,$(OSTYPE)),$(call find_exe,apt-get)))
+          $(info *** Info *** Install the development components of libSDL or libSDL2)
+          $(info *** Info *** packaged for your operating system distribution for)
+          $(info *** Info *** your Linux system:)
+          $(info *** Info ***        # apt-get install libsdl2-dev)
+          $(info *** Info ***    or)
+          $(info *** Info ***        # apt-get install libsdl-dev)
+        else
+          $(info *** Info *** Install the development components of libSDL packaged by your)
+          $(info *** Info *** operating system distribution and rebuild your simulator to)
+          $(info *** Info *** enable this extra functionality.)
+        endif
+	  endif
       $(info *** Info ***)
     endif
   endif
@@ -581,9 +638,15 @@ ifeq ($(WIN32),)  #*nix Environments (&& cygwin)
         $(info *** Warning *** libpcap networking support)
         $(info *** Warning ***)
         $(info *** Warning *** To build simulator(s) with libpcap networking support you)
-        $(info *** Warning *** should read 0readme_ethernet.txt and follow the instructions)
-        $(info *** Warning *** regarding the needed libpcap development components for your)
-        $(info *** Warning *** $(OSTYPE) platform)
+        ifneq (,$(and $(findstring Linux,$(OSTYPE)),$(call find_exe,apt-get)))
+          $(info *** Warning *** should install the libpcap development components for)
+          $(info *** Warning *** for your Linux system:)
+          $(info *** Warning ***        # apt-get install libpcap-dev)
+        else
+          $(info *** Warning *** should read 0readme_ethernet.txt and follow the instructions)
+          $(info *** Warning *** regarding the needed libpcap development components for your)
+          $(info *** Warning *** $(OSTYPE) platform)
+        endif
         $(info *** Warning ***)
       endif
     endif
@@ -616,13 +679,26 @@ ifeq ($(WIN32),)  #*nix Environments (&& cygwin)
           $(info *** Info *** minimal libpcap networking support)
           $(info *** Info ***)
         endif
+        $(info *** Info ***)
         $(info *** Info *** Simulators on your $(OSNAME) platform can also be built with)
         $(info *** Info *** extended LAN Ethernet networking support by using VDE Ethernet.)
         $(info *** Info ***)
         $(info *** Info *** To build simulator(s) with extended networking support you)
-        $(info *** Info *** should read 0readme_ethernet.txt and follow the instructions)
-        $(info *** Info *** regarding the needed libvdeplug components for your $(OSNAME))
-        $(info *** Info *** platform)
+        ifeq (Darwin,$(OSTYPE))
+          $(info *** Info *** should install the MacPorts vde2 package to provide this)
+          $(info *** Info *** functionality for your OS X system:)
+          $(info *** Info ***       # port install vde2)
+        else
+          ifneq (,$(and $(findstring Linux,$(OSTYPE)),$(call find_exe,apt-get)))
+            $(info *** Info *** should install the vde2 package to provide this)
+            $(info *** Info *** functionality for your $(OSNAME) system:)
+            $(info *** Info ***        # apt-get install vde2)
+          else
+            $(info *** Info *** should read 0readme_ethernet.txt and follow the instructions)
+            $(info *** Info *** regarding the needed libvdeplug components for your $(OSNAME))
+            $(info *** Info *** platform)
+          endif
+        endif
         $(info *** Info ***)
       endif
     endif
@@ -802,6 +878,9 @@ endif # Win32 (via MinGW)
 ifneq (,$(GIT_COMMIT_ID))
   CFLAGS_GIT = -DSIM_GIT_COMMIT_ID=$(GIT_COMMIT_ID)
 endif
+ifneq (,$(UNSUPPORTED_BUILD))
+  CFLAGS_GIT += -DSIM_BUILD=Unsupported=$(UNSUPPORTED_BUILD)
+endif
 ifneq ($(DEBUG),)
   CFLAGS_G = -g -ggdb -g3
   CFLAGS_O = -O0