diff --git a/rtl/aix/Makefile.fpc b/rtl/aix/Makefile.fpc
index 97f0c58f67..9e755c57e4 100644
--- a/rtl/aix/Makefile.fpc
+++ b/rtl/aix/Makefile.fpc
@@ -19,7 +19,7 @@ units=$(SYSTEMUNIT) $(UUCHARUNIT) $(UNIXTYPEUNIT) $(CTYPESUNIT) $(STRINGSUNIT) $
       $(DLUNIT) $(DYNLIBSUNIT) \
       $(TYPESUNIT) $(SYSCONSTUNIT) \
       $(RTLCONSTSUNIT) $(CTHREADSUNIT) \
-      dos \
+      $(DOSUNIT) \
       $(CWSTRINGUNIT) $(FPWIDESTRINGUNIT) $(FPINTRESUNIT) $(CPU_UNITS) \
       $(SOFTFPUUNIT) $(SFPUX80UNIT) $(UFLOATX80UNIT) $(SFPU128UNIT) $(UFLOAT128UNIT)
 implicitunits=$(CP_UNITS) $(UNICODEDATAUNIT)
@@ -45,7 +45,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       $(UNIXUNIT)  \
-      dos crt   \
+      $(DOSUNIT) crt   \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPU_UNITS) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT) sockets
@@ -64,6 +64,7 @@ DYNLIBS_DEPS_OS=$(DLUNIT)$(PPUEXT)
 DYNLIBSINCDIR=$(UNIXINC)
 DL_DEPS_OS=$(DLUNIT)aix.inc
 TERMIO_DEPS_OS=$(UNIXTYPEUNIT)$(PPUEXT) $(CTYPESUNIT)$(PPUEXT)
+DOSDIR=$(UNIXINC)
 
 SYSTEMUNIT=system
 
@@ -116,17 +117,6 @@ SYSDEPS=$(SYSINCDEPS) $(SYSCPUDEPS)
 $(SYSTEMUNIT)$(PPUEXT) : $(SYSTEMUNIT).pp $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg $(SYSTEMUNIT).pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : strings$(PPUEXT) $(UNIXUNIT)$(PPUEXT) $(UNIXINC)/dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               $(SYSTEMUNIT)$(PPUEXT)
-	$(COMPILER) $(UNIXINC)/dos.pp
-#
-# Graph
-#
-
 #
 # Delphi Compatible Units
 #
diff --git a/rtl/android/Makefile.fpc b/rtl/android/Makefile.fpc
index 08f22bbaa7..4add4cbf61 100644
--- a/rtl/android/Makefile.fpc
+++ b/rtl/android/Makefile.fpc
@@ -13,7 +13,7 @@ units=$(SYSTEMUNIT) $(SYSINIT_UNITS) $(CPU_UNITS) \
       $(LINUXVCSUNIT) sysutils $(TYPINFOUNIT) $(MATHUNIT) $(CHARSETUNIT) $(CPALLUNIT) $(CHARACTERUNIT) \
       $(GETOPTSUNIT) $(ERRORSUNIT) $(DLUNIT) $(DYNLIBSUNIT) \
       $(TYPESUNIT) $(SYSCONSTUNIT) $(CTHREADSUNIT) $(SORTBASEUNIT) classes $(FGLUNIT)  \
-      $(RTLCONSTSUNIT) dos $(CWSTRINGUNIT) $(FPCYLIXUNIT) $(UNIXCPUNIT) $(FPWIDESTRINGUNIT) \
+      $(RTLCONSTSUNIT) $(DOSUNIT) $(CWSTRINGUNIT) $(FPCYLIXUNIT) $(UNIXCPUNIT) $(FPWIDESTRINGUNIT) \
       $(SOFTFPUUNIT) $(SFPUX80UNIT) $(UFLOATX80UNIT) $(SFPU128UNIT) $(UFLOAT128UNIT)
 implicitunits=$(EXEINFOUNIT) $(CP_UNITS) $(UNICODEDATAUNIT)
 rsts=$(MATHUNIT)  $(TYPINFOUNIT)  $(SYSCONSTUNIT) $(RTLCONSTSUNIT)
@@ -36,7 +36,7 @@ sourcedir=$(INC) $(PROCINC) $(UNIXINC) $(ARCH) $(COMMON) $(LINUXINC)
 targetdir=.
 
 [shared]
-libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) dos \
+libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) $(DOSUNIT) \
       $(UNIXUNIT) $(BASEUNIXUNIT) $(UNIXTYPEUNIT) $(UNIXUTILUNIT) \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPU_UNITS) $(GETOPTSUNIT) \
@@ -139,14 +139,6 @@ dllprt0$(OEXT) : dllprt0.as
 $(SYSTEMUNIT)$(PPUEXT) : $(LINUXINC)/$(SYSTEMUNIT).pp $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg $(LINUXINC)/$(SYSTEMUNIT).pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : $(UNIXINC)/dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               $(UNIXUNIT)$(PPUEXT) $(SYSTEMUNIT)$(PPUEXT)
-        $(COMPILER) $(UNIXINC)/dos.pp
-
 #
 # Delphi Compatible Units
 #
diff --git a/rtl/beos/Makefile.fpc b/rtl/beos/Makefile.fpc
index a7a72e548f..d1e28721fb 100644
--- a/rtl/beos/Makefile.fpc
+++ b/rtl/beos/Makefile.fpc
@@ -41,7 +41,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       unix  \
-      dos crt  \
+      $(DOSUNIT) crt  \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPU_UNITS) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT) $(DYNLIBSUNIT)
diff --git a/rtl/dragonfly/Makefile.fpc b/rtl/dragonfly/Makefile.fpc
index a327b0c45b..7eecdaa3d1 100644
--- a/rtl/dragonfly/Makefile.fpc
+++ b/rtl/dragonfly/Makefile.fpc
@@ -18,7 +18,7 @@ units=$(SYSTEMUNIT) $(UUCHARUNIT) $(UNIXTYPEUNIT) $(CTYPESUNIT) $(OBJPASUNIT) $(
       $(CPU_UNITS) $(CHARSETUNIT) $(CPALLUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) $(LNFODWRFUNIT) $(LINEINFOUNIT) \
       $(ERRORSUNIT) $(BSDUNIT) \
       $(CONSOLEUNIT) \
-      $(SYSCONSTUNIT) $(CTHREADSUNIT) dos $(CWSTRINGUNIT) \
+      $(SYSCONSTUNIT) $(CTHREADSUNIT) $(DOSUNIT) $(CWSTRINGUNIT) \
       $(FPINTRESUNIT) $(UNIXCPUNIT) $(FPWIDESTRINGUNIT) \
       $(SOFTFPUUNIT) $(SFPUX80UNIT) $(UFLOATX80UNIT) $(SFPU128UNIT) $(UFLOAT128UNIT)
 implicitunits=$(EXEINFOUNIT) $(CP_UNITS) $(UNICODEDATAUNIT)
@@ -44,7 +44,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       $(UNIXUNIT)  \
-      dos  \
+      $(DOSUNIT)  \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPU_UNITS) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT) $(DYNLIBSUNIT)
@@ -62,6 +62,7 @@ UNITPREFIX=rtl
 CPU_UNITS=
 
 BSD_DEPS_OS=$(SYSCALLUNIT)$(PPUEXT)
+DOSDIR=$(UNIXINC)
 
 DYNLIBS_DEPS_OS=$(DLUNIT)$(PPUEXT)
 DYNLIBSINCDIR=$(UNIXINC)
@@ -127,14 +128,6 @@ dllprt0$(OEXT) : $(CPU_TARGET)/dllprt0.as
 $(SYSTEMUNIT)$(PPUEXT) : $(BSDINC)/$(SYSTEMUNIT).pp unxconst.inc $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg $(BSDINC)/$(SYSTEMUNIT).pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : $(UNIXINC)/dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               $(UNIXUNIT)$(PPUEXT) $(SYSTEMUNIT)$(PPUEXT)
-
-
 #
 # Delphi Compatible Units
 #
diff --git a/rtl/freebsd/Makefile.fpc b/rtl/freebsd/Makefile.fpc
index f447d9aea4..799947ec8e 100644
--- a/rtl/freebsd/Makefile.fpc
+++ b/rtl/freebsd/Makefile.fpc
@@ -18,7 +18,7 @@ units=$(SYSTEMUNIT) $(UUCHARUNIT) $(UNIXTYPEUNIT) $(CTYPESUNIT) $(OBJPASUNIT) $(
       $(CPU_UNITS) $(CHARSETUNIT) $(CPALLUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) $(LNFODWRFUNIT) $(LINEINFOUNIT) \
       $(ERRORSUNIT) $(BSDUNIT) freebsd \
       $(CONSOLEUNIT) \
-      $(SYSCONSTUNIT) $(CTHREADSUNIT) dos $(CWSTRINGUNIT) \
+      $(SYSCONSTUNIT) $(CTHREADSUNIT) $(DOSUNIT) $(CWSTRINGUNIT) \
       $(FPINTRESUNIT) $(UNIXCPUNIT) $(FPWIDESTRINGUNIT) \
       $(SOFTFPUUNIT) $(SFPUX80UNIT) $(UFLOATX80UNIT) $(SFPU128UNIT) $(UFLOAT128UNIT)
 implicitunits=$(EXEINFOUNIT) $(CP_UNITS) $(UNICODEDATAUNIT)
@@ -44,7 +44,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       $(UNIXUNIT)  \
-      dos  \
+      $(DOSUNIT)  \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPU_UNITS) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT) $(DYNLIBSUNIT)
@@ -63,6 +63,7 @@ UNITPREFIX=rtl
 CPU_UNITS=
 BASEUNIX_DEPS_OS=$(SYSCTLUNIT)$(PPUEXT)
 BSD_DEPS_OS=$(SYSCALLUNIT)$(PPUEXT)
+DOSDIR=$(UNIXINC)
 DYNLIBS_DEPS_OS=$(DLUNIT)$(PPUEXT)
 DYNLIBSINCDIR=$(UNIXINC)
 
@@ -132,14 +133,6 @@ dllprt0$(OEXT) : $(CPU_TARGET)/dllprt0.as
 $(SYSTEMUNIT)$(PPUEXT) : $(BSDINC)/$(SYSTEMUNIT).pp unxconst.inc $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg $(BSDINC)/$(SYSTEMUNIT).pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : $(UNIXINC)/dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               $(UNIXUNIT)$(PPUEXT) $(SYSTEMUNIT)$(PPUEXT)
-        $(COMPILER) $<
-
 #
 # Delphi Compatible Units
 #
diff --git a/rtl/go32v2/Makefile.fpc b/rtl/go32v2/Makefile.fpc
index 98e42a47b9..c7327ab978 100644
--- a/rtl/go32v2/Makefile.fpc
+++ b/rtl/go32v2/Makefile.fpc
@@ -7,7 +7,7 @@ main=rtl
 loaders=prt0 exceptn fpu
 units=system $(UUCHARUNIT) $(OBJPASUNIT) $(MACPASUNIT) $(ISO7185UNIT) $(EXTPASUNIT) $(STRINGSUNIT) \
       go32 dpmiexcp $(INITCUNIT) $(PORTSUNIT) profile dxetype dxeload emu387 \
-      dos $(CMEMUNIT) $(SORTBASEUNIT) \
+      $(DOSUNIT) $(CMEMUNIT) $(SORTBASEUNIT) \
       sysutils classes $(MATHUNIT) $(TYPINFOUNIT) \
       $(CPUUNIT) $(MMXUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) $(LINEINFOUNIT) $(LNFODWRFUNIT) $(CTYPESUNIT) $(FGLUNIT) \
       $(MSMOUSEUNIT) $(CHARSETUNIT) $(CPALLUNIT) \
@@ -109,19 +109,11 @@ emu387$(PPUEXT) : emu387.pp fpu$(OEXT) strings$(PPUEXT) dxeload$(PPUEXT) \
 	$(COMPILER) emu387.pp
 	$(EXECPPAS)
 
-#
-# TP7 Compatible RTL Units
-#
-dos$(PPUEXT) : dos.pp $(INC)/filerec.inc $(INC)/textrec.inc \
-	       go32$(PPUEXT) strings$(PPUEXT) system$(PPUEXT)
-	$(COMPILER) dos.pp
-	$(EXECPPAS)
-
 #
 # Delphi Compatible Units
 #
 sysutils$(PPUEXT) : sysutils.pp $(wildcard $(OBJPASDIR)/sysutils/*.inc) \
-		    $(OBJPASUNIT)$(PPUEXT) dos$(PPUEXT) go32$(PPUEXT) $(SYSCONSTUNIT)$(PPUEXT)
+		    $(OBJPASUNIT)$(PPUEXT) $(DOSUNIT)$(PPUEXT) go32$(PPUEXT) $(SYSCONSTUNIT)$(PPUEXT)
 	$(COMPILER) -Fi$(OBJPASDIR)/sysutils sysutils.pp
 	$(EXECPPAS)
 
diff --git a/rtl/haiku/Makefile.fpc b/rtl/haiku/Makefile.fpc
index b9e5887dd3..7ea9b81828 100644
--- a/rtl/haiku/Makefile.fpc
+++ b/rtl/haiku/Makefile.fpc
@@ -41,7 +41,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       unix  \
-      dos \
+      $(DOSUNIT) \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPU_UNITS) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT) $(DYNLIBSUNIT)
diff --git a/rtl/msxdos/Makefile.fpc b/rtl/msxdos/Makefile.fpc
index 1eb6a6b971..43757612d9 100644
--- a/rtl/msxdos/Makefile.fpc
+++ b/rtl/msxdos/Makefile.fpc
@@ -7,7 +7,7 @@ main=rtl
 #loaders=prt0s prt0t prt0m prt0c prt0l prt0h # exceptn fpu
 units=system si_prc $(UUCHARUNIT) $(OBJPASUNIT) $(ISO7185UNIT) $(STRINGSUNIT) $(CHARSETUNIT) $(CPALLUNIT) \
       $(GETOPTSUNIT) $(EXEINFOUNIT) $(HEAPTRCUNIT)
-#$(UUCHARUNIT) $(OBJPASUNIT) $(STRINGSUNIT) dos $(HEAPTRCUNIT) $(LNFODWRFUNIT) $(SYSCONSTUNIT) sysutils \
+#$(UUCHARUNIT) $(OBJPASUNIT) $(STRINGSUNIT) $(DOSUNIT) $(HEAPTRCUNIT) $(LNFODWRFUNIT) $(SYSCONSTUNIT) sysutils \
 #      $(MATHUNIT) $(MACPASUNIT) $(ISO7185UNIT) $(EXTPASUNIT) $(RTLCONSTSUNIT) $(TYPINFOUNIT) $(CPUUNIT) $(TYPESUNIT) \
 #      $(GETOPTSUNIT) $(SORTBASEUNIT) $(FGLUNIT) classes \
 #      $(MSMOUSEUNIT) $(PORTSUNIT)  \
@@ -38,6 +38,8 @@ PROCINC=../$(CPU_TARGET)
 UNITPREFIX=rtl
 SYSTEMUNIT=system
 
+DOS_DEPS_OS =  registers.inc $(INC)/dosh.inc $(INC)/dos.inc $(INC)/fexpand.inc
+
 # Paths
 OBJPASDIR=$(RTL)/objpas
 # Insert exception handler in system unit
@@ -79,20 +81,11 @@ system$(PPUEXT) : system.pp $(SYSDEPS) $(INC)/tnyheaph.inc $(INC)/tinyheap.inc r
 # System Dependent Units
 #
 
-#
-# TP7 Compatible RTL Units
-#
-dos$(PPUEXT) : dos.pp registers.inc \
-               $(INC)/dosh.inc $(INC)/dos.inc $(INC)/fexpand.inc \
-               strings$(PPUEXT) system$(PPUEXT)
-	$(COMPILER) dos.pp
-	$(EXECPPAS)
-
 #
 # Delphi Compatible Units
 #
 sysutils$(PPUEXT) : sysutils.pp $(wildcard $(OBJPASDIR)/sysutils/*.inc) \
-                    $(OBJPASUNIT)$(PPUEXT) dos$(PPUEXT) $(SYSCONSTUNIT)$(PPUEXT) system$(PPUEXT)
+                    $(OBJPASUNIT)$(PPUEXT) $(DOSUNIT)$(PPUEXT) $(SYSCONSTUNIT)$(PPUEXT) system$(PPUEXT)
         $(COMPILER) -Fi$(OBJPASDIR)/sysutils sysutils.pp
 	$(EXECPPAS)
 
diff --git a/rtl/nativent/Makefile.fpc b/rtl/nativent/Makefile.fpc
index ff317a3772..3b6ce30371 100644
--- a/rtl/nativent/Makefile.fpc
+++ b/rtl/nativent/Makefile.fpc
@@ -13,7 +13,7 @@ implicitunits=ndk ndkutils ddk \
       $(CTYPESUNIT) $(STRINGSUNIT) \
 #      $(HEAPTRCUNIT)
 #      $(INITCUNIT) $(CMEMUNIT) $(DYNLIBSUNIT) signals \
-      dos \
+      $(DOSUNIT) \
       $(RTLCONSTSUNIT) $(SYSCONSTUNIT) sysutils $(MATHUNIT) $(TYPESUNIT) \
       $(TYPINFOUNIT) $(FGLUNIT) classes \
       $(CPU_UNITS) $(CHARSETUNIT) $(GETOPTSUNIT) \
diff --git a/rtl/netbsd/Makefile.fpc b/rtl/netbsd/Makefile.fpc
index 04fd130f98..95dc81b9f3 100644
--- a/rtl/netbsd/Makefile.fpc
+++ b/rtl/netbsd/Makefile.fpc
@@ -17,7 +17,7 @@ units=$(SYSTEMUNIT) $(UUCHARUNIT) $(UNIXTYPEUNIT) $(CTYPESUNIT) $(OBJPASUNIT) $(
       sysutils $(MATHUNIT) $(TYPINFOUNIT) $(TYPESUNIT) $(SORTBASEUNIT) classes $(FGLUNIT) $(DYNLIBSUNIT) \
       $(CPU_UNITS) $(CHARSETUNIT) $(CPALLUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) $(LNFODWRFUNIT) $(LINEINFOUNIT) \
       $(ERRORSUNIT) $(BSDUNIT) \
-      $(SYSCONSTUNIT) $(CTHREADSUNIT) dos $(CWSTRINGUNIT) \
+      $(SYSCONSTUNIT) $(CTHREADSUNIT) $(DOSUNIT) $(CWSTRINGUNIT) \
       $(FPINTRESUNIT) $(UNIXCPUNIT) $(FPWIDESTRINGUNIT) \
       $(SOFTFPUUNIT) $(SFPUX80UNIT) $(UFLOATX80UNIT) $(SFPU128UNIT) $(UFLOAT128UNIT)
 implicitunits=$(EXEINFOUNIT) $(CP_UNITS) $(UNICODEDATAUNIT)
@@ -43,7 +43,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       $(UNIXUNIT)  \
-      dos \
+      $(DOSUNIT) \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPUUNIT) $(MMXUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT) 
@@ -62,6 +62,7 @@ TARGETPROCINC=$(RTL)/netbsd/$(CPU_TARGET)
 
 BASEUNIX_DEPS_OS=$(SYSCTLUNIT)$(PPUEXT)
 BSD_DEPS_OS=$(SYSCALLUNIT)$(PPUEXT)
+DOSDIR=$(UNIXINC)
 DYNLIBS_DEPS_OS=$(DLUNIT)$(PPUEXT)
 DYNLIBSINCDIR=$(UNIXINC)
 SYSCALL_DEPS_OS=$(BASEUNIXUNIT)$(PPUEXT) $(UNIXTYPEUNIT)$(PPUEXT) sysnr.inc $(BSDPROCINC)/syscallh.inc
@@ -126,17 +127,6 @@ dllprt0$(OEXT) : $(CPU_TARGET)/dllprt0.as
 $(SYSTEMUNIT)$(PPUEXT) : $(BSDINC)/$(SYSTEMUNIT).pp sysconst.inc systypes.inc syscalls.inc $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg $(BSDINC)/$(SYSTEMUNIT).pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : $(UNIXINC)/dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               $(UNIXUNIT)$(PPUEXT) $(SYSTEMUNIT)$(PPUEXT)
-	$(COMPILER) $<
-#
-# Graph
-#
-
 #
 # Delphi Compatible Units
 #
diff --git a/rtl/netwlibc/Makefile.fpc b/rtl/netwlibc/Makefile.fpc
index 57439fabc7..1c4ece3057 100644
--- a/rtl/netwlibc/Makefile.fpc
+++ b/rtl/netwlibc/Makefile.fpc
@@ -9,7 +9,7 @@ main=rtl
 loaders=nwplibc nwl_main nwl_dlle
 units=$(SYSTEMUNIT) $(UUCHARUNIT) $(OBJPASUNIT) $(MACPASUNIT) $(ISO7185UNIT) $(EXTPASUNIT) $(STRINGSUNIT) \
       $(LINEINFOUNIT) $(LNFODWRFUNIT)  $(HEAPTRCUNIT) \
-      nwsnut libc dos $(SYSCONSTUNIT) \
+      nwsnut libc $(DOSUNIT) $(SYSCONSTUNIT) \
       $(INITCUNIT) sysutils $(TYPESUNIT) $(TYPINFOUNIT) $(SORTBASEUNIT) $(FGLUNIT) classes \
       $(CPUUNIT) $(MMXUNIT) $(GETOPTSUNIT) \
       $(CHARSETUNIT) $(CPALLUNIT) \
@@ -131,18 +131,12 @@ netware$(PPUEXT) : netware.pp $(SYSTEMUNIT)$(PPUEXT)
 
 nwsnut$(PPUEXT) : nwsnut.pp ../netware/nwsnut.pp libc$(PPUEXT) $(SYSTEMUNIT)$(PPUEXT)
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : dos.pp libc.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) $(SYSTEMUNIT)$(PPUEXT)
-
 #
 # Delphi Compatible Units
 #
 
 sysutils$(PPUEXT) : sysutils.pp $(wildcard $(OBJPASDIR)/sysutils/*.inc) \
-                    $(OBJPASUNIT)$(PPUEXT) dos$(PPUEXT) libc.pp $(SYSCONSTUNIT)$(PPUEXT)
+                    $(OBJPASUNIT)$(PPUEXT) $(DOSUNIT)$(PPUEXT) libc.pp $(SYSCONSTUNIT)$(PPUEXT)
         $(COMPILER) -Fi$(OBJPASDIR)/sysutils sysutils.pp
 
 classes$(PPUEXT) : classes.pp $(wildcard $(OBJPASDIR)/classes/*.inc) \
diff --git a/rtl/openbsd/Makefile.fpc b/rtl/openbsd/Makefile.fpc
index 1212a96514..5812731a7f 100644
--- a/rtl/openbsd/Makefile.fpc
+++ b/rtl/openbsd/Makefile.fpc
@@ -12,7 +12,7 @@ fpcpackage=y
 loaders=$(LOADERS)
 units=$(SYSTEMUNIT) $(SYSINIT_UNITS) $(INITCUNIT) $(UUCHARUNIT) $(OBJPASUNIT) $(MACPASUNIT) $(ISO7185UNIT) $(EXTPASUNIT) $(STRINGSUNIT) $(SYSCALLUNIT) $(BASEUNIXUNIT) \
       $(LINUXUNIT) $(UNIXTYPEUNIT) $(UNIXUTILUNIT) $(UNIXUNIT) $(CTYPESUNIT) $(BSDUNIT) \
-      $(CPU_UNITS) dos $(RTLCONSTSUNIT) \
+      $(CPU_UNITS) $(DOSUNIT) $(RTLCONSTSUNIT) \
       sysutils $(SORTBASEUNIT) $(FGLUNIT) classes $(TYPINFOUNIT) $(MATHUNIT) \
       $(CHARSETUNIT) $(CPALLUNIT) $(CHARACTERUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) $(LINEINFOUNIT) $(LNFODWRFUNIT) \
       $(ERRORSUNIT) \
@@ -43,7 +43,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       $(UNIXUNIT)  \
-      dos  \
+      $(DOSUNIT)  \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPUUNIT) $(MMXUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT)
@@ -61,6 +61,7 @@ TARGETPROCINC=$(RTL)/openbsd/$(CPU_TARGET)
 
 BASEUNIX_DEPS_OS=$(SYSCTLUNIT)$(PPUEXT)
 BSD_DEPS_OS=$(SYSCALLUNIT)$(PPUEXT)
+DOSDIR=$(UNIXINC)
 DYNLIBS_DEPS_OS=$(DLUNIT)$(PPUEXT)
 DYNLIBSINCDIR=$(UNIXINC)
 SYSCALL_DEPS_OS=$(BASEUNIXUNIT)$(PPUEXT) $(UNIXTYPEUNIT)$(PPUEXT) sysnr.inc setsysnr.inc $(BSDPROCINC)/syscallh.inc
@@ -145,18 +146,6 @@ si_g$(PPUEXT) : si_g.pp si_intf.inc si_impl.inc $(ARCH)/openbsd_ident.inc $(ARCH
 $(SYSTEMUNIT)$(PPUEXT) : $(BSDINC)/$(SYSTEMUNIT).pp sysconst.inc systypes.inc syscalls.inc $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg $(BSDINC)/$(SYSTEMUNIT).pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : $(UNIXINC)/dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               $(UNIXUNIT)$(PPUEXT) $(SYSTEMUNIT)$(PPUEXT)
-	$(COMPILER) $(UNIXINC)/dos.pp
-
-#
-# Graph
-#
-
 #
 # Delphi Compatible Units
 #
diff --git a/rtl/palmos/Makefile.fpc b/rtl/palmos/Makefile.fpc
index 0bdfbcd981..516f7f11df 100644
--- a/rtl/palmos/Makefile.fpc
+++ b/rtl/palmos/Makefile.fpc
@@ -15,7 +15,7 @@ units=$(SYSTEMUNIT) si_prc $(UUCHARUNIT) $(OBJPASUNIT) $(ISO7185UNIT) $(STRINGSU
 #units=$(SYSTEMUNIT) $(UUCHARUNIT) $(CTYPESUNIT) $(OBJPASUNIT) $(MACPASUNIT) $(ISO7185UNIT) $(EXTPASUNIT) $(STRINGSUNIT) \
 #      $(LNFODWRFUNIT) $(LINEINFOUNIT) $(HEAPTRCUNIT) \
 #      windows messages $(DYNLIBSUNIT) \
-#      dos objects \
+#      $(DOSUNIT) objects \
 #      $(RTLCONSTSUNIT) $(SYSCONSTUNIT) sysutils \
 #      $(TYPINFOUNIT) $(TYPESUNIT) $(FGLUNIT) classes fmtbcd \
 #      strutils convutils $(MATHUNIT) dateutils \
@@ -117,9 +117,6 @@ pilot$(PPUEXT) : pilot.pp $(SYSTEMUNIT)$(PPUEXT) systraps$(PPUEXT)
 # TP7 Compatible RTL Units
 #
 
-#dos$(PPUEXT) : $(DOSDEPS) $(SYSTEMPPU)
-#	$(PP) $(OPT) dos $(REDIR)
-
 #crt$(PPUEXT) : crt.pp $(INC)/textrec.inc $(INC)/filerec.inc $(SYSTEMPPU)
 #	$(PP) $(OPT) crt $(REDIR)
 
diff --git a/rtl/qnx/Makefile.fpc b/rtl/qnx/Makefile.fpc
index 9adb911d9a..4715049d80 100644
--- a/rtl/qnx/Makefile.fpc
+++ b/rtl/qnx/Makefile.fpc
@@ -7,7 +7,7 @@ main=rtl
 
 [target]
 loaders=cprt0 crti crtn
-units=system $(UUCHARUNIT) dos $(OBJPASUNIT) objects $(STRINGSUNIT) \
+units=system $(UUCHARUNIT) $(DOSUNIT) $(OBJPASUNIT) objects $(STRINGSUNIT) \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPUUNIT) $(MMXUNIT) $(GETOPTSUNIT) $(HEAPTRCUNIT) $(LINEINFOUNIT) posix
 rsts=$(MATHUNIT) $(TYPINFOUNIT)
@@ -90,20 +90,12 @@ dllprt$(OEXT) : $(CPU_TARGET)/dllprt.as
 system$(PPUEXT) : system.pp $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg system.pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               posix$(PPUEXT) system$(PPUEXT)
-        $(COMPILER) $(POSIXINC)/dos.pp
-
 #
 # Delphi Compatible Units
 #
 
 sysutils$(PPUEXT) : $(POSIXINC)/sysutils.pp $(wildcard $(OBJPASDIR)/*.inc) \
-                    $(OBJPASUNIT)$(PPUEXT) dos$(PPUEXT)
+                    $(OBJPASUNIT)$(PPUEXT) $(DOSUNIT)$(PPUEXT)
         $(COMPILER) -I$(OBJPASDIR) $(POSIXINC)/sysutils.pp
 
 #
diff --git a/rtl/solaris/Makefile.fpc b/rtl/solaris/Makefile.fpc
index 0de47ac1e6..ad92def13a 100644
--- a/rtl/solaris/Makefile.fpc
+++ b/rtl/solaris/Makefile.fpc
@@ -17,7 +17,7 @@ units=$(SYSTEMUNIT) $(UUCHARUNIT) $(UNIXTYPEUNIT) $(CTYPESUNIT) $(STRINGSUNIT) $
       $(DLUNIT) $(DYNLIBSUNIT) \
       $(TYPESUNIT) $(SYSCONSTUNIT) $(CHARACTERUNIT) \
       $(RTLCONSTSUNIT) $(CTHREADSUNIT) \
-      dos $(FPWIDESTRINGUNIT) \
+      $(DOSUNIT) $(FPWIDESTRINGUNIT) \
       $(CWSTRINGUNIT) $(FPINTRESUNIT) $(CPU_UNITS) \
       $(SOFTFPUUNIT) $(SFPUX80UNIT) $(UFLOATX80UNIT) $(SFPU128UNIT) $(UFLOAT128UNIT)
 
@@ -44,7 +44,7 @@ libname=libfprtl.so
 libversion=2.0.0
 libunits=$(SYSTEMUNIT) $(OBJPASUNIT) $(STRINGSUNIT) \
       $(UNIXUNIT)  \
-      dos \
+      $(DOSUNIT) \
       sysutils $(TYPINFOUNIT) $(MATHUNIT) \
       $(CPU_UNITS) $(GETOPTSUNIT) $(HEAPTRCUNIT) \
       $(ERRORSUNIT)
@@ -58,6 +58,7 @@ OSPROCINC=$(RTL)/solaris/$(CPU_TARGET)
 UNIXINC=$(RTL)/unix
 UNITPREFIX=rtl
 CPU_UNITS=
+DOSDIR=$(UNIXINC)
 DYNLIBS_DEPS_OS=$(DLUNIT)$(PPUEXT)
 DYNLIBSINCDIR=$(UNIXINC)
 TERMIO_DEPS_OS=$(UNIXTYPEUNIT)$(PPUEXT)
@@ -113,18 +114,6 @@ SYSDEPS=$(SYSINCDEPS) $(SYSCPUDEPS)
 $(SYSTEMUNIT)$(PPUEXT) : $(SYSTEMUNIT).pp $(SYSDEPS)
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg $(SYSTEMUNIT).pp
 
-#
-# TP7 Compatible RTL Units
-#
-
-dos$(PPUEXT) : strings$(PPUEXT) $(UNIXUNIT)$(PPUEXT) $(UNIXINC)/dos.pp $(INC)/filerec.inc $(INC)/textrec.inc strings$(PPUEXT) \
-               $(SYSTEMUNIT)$(PPUEXT)
-	$(COMPILER) $(UNIXINC)/dos.pp
-
-#
-# Graph
-#
-
 #
 # Delphi Compatible Units
 #
diff --git a/rtl/win16/Makefile.fpc b/rtl/win16/Makefile.fpc
index 6ea6de945c..3d8fea6bba 100644
--- a/rtl/win16/Makefile.fpc
+++ b/rtl/win16/Makefile.fpc
@@ -5,7 +5,7 @@
 main=rtl
 [target]
 loaders=prt0s prt0m prt0c prt0l prt0h 
-units=system $(UUCHARUNIT) $(OBJPASUNIT) $(STRINGSUNIT) $(ISO7185UNIT) $(EXTPASUNIT) dos \
+units=system $(UUCHARUNIT) $(OBJPASUNIT) $(STRINGSUNIT) $(ISO7185UNIT) $(EXTPASUNIT) $(DOSUNIT) \
       $(WINTYPESUNIT) $(WINPROCSUNIT) $(WIN31UNIT) $(PORTSUNIT) $(DYNLIBSUNIT) $(SORTBASEUNIT) \
       $(SYSCONSTUNIT) $(RTLCONSTSUNIT) sysutils $(MATHUNIT) $(TYPESUNIT) $(TYPINFOUNIT) $(FGLUNIT) \
       classes $(CHARSETUNIT) $(CPUUNIT) $(GETOPTSUNIT) $(CPALLUNIT) \
@@ -31,6 +31,7 @@ UNITPREFIX=rtl
 SYSTEMUNIT=system
 
 TYPES_DEPS_OS=$(WINTYPESUNIT)$(PPUEXT)
+DOS_DEPS_OS = registers.inc $(INC)/dosh.inc $(INC)/dos.inc $(INC)/fexpand.inc
 
 # Paths
 OBJPASDIR=$(RTL)/objpas
@@ -82,20 +83,11 @@ system$(PPUEXT) : system.pp $(SYSDEPS) wintypes.inc winprocsh.inc winprocs.inc \
         $(COMPILER) $(FPC_SYSTEM_OPT) -Us -Sg system.pp
 	$(EXECPPAS)
 
-#
-# TP7 Compatible RTL Units
-#
-dos$(PPUEXT) : dos.pp registers.inc \
-               $(INC)/dosh.inc $(INC)/dos.inc $(INC)/fexpand.inc \
-               strings$(PPUEXT) $(WINTYPESUNIT)$(PPUEXT) $(WINPROCSUNIT)$(PPUEXT) system$(PPUEXT)
-	$(COMPILER) dos.pp
-	$(EXECPPAS)
-
 #
 # Delphi Compatible Units
 #
 sysutils$(PPUEXT) : sysutils.pp $(wildcard $(OBJPASDIR)/sysutils/*.inc) \
-                    $(OBJPASUNIT)$(PPUEXT) dos$(PPUEXT) $(SYSCONSTUNIT)$(PPUEXT) \
+                    $(OBJPASUNIT)$(PPUEXT) $(DOSUNIT)$(PPUEXT) $(SYSCONSTUNIT)$(PPUEXT) \
                     $(WINTYPESUNIT)$(PPUEXT) $(WINPROCSUNIT)$(PPUEXT) system$(PPUEXT)
         $(COMPILER) -Fi$(OBJPASDIR)/sysutils sysutils.pp
 	$(EXECPPAS)