added a watcom makefile for targeting dos

Makefile.dos

@@ -0,0 +1,51 @@
+# Makefile for MS-DOS using Watcom compiler.
+#
+# wmake -f Makefile.dos
+# - builds using the static library xmp_static.lib
+#
+# change libxmp_path as needed (or specify on the wmake cmdline)
+!ifndef libxmp_path
+libxmp_path = ../libxmp
+!endif
+
+CC=wcc386
+# SYSTEM can be dos32a, causeway or dos4g:
+SYSTEM=dos32a
+
+CPPFLAGS=-DHAVE_SIGNAL_H -DHAVE_STRINGS_H
+
+INCLUDES=-I"src/watcom" -Isrc -I"$(%WATCOM)/h"
+
+CPPFLAGS+= -DBUILDING_STATIC
+LIBXMP=$(libxmp_path)/xmp_static.lib
+INCLUDES+= -I"$(libxmp_path)/include"
+LIBS=$(LIBXMP)
+
+CFLAGS = -bt=dos -fp5 -fpi87 -mf -oeatxh -w4 -zp8 -ei -q
+# newer OpenWatcom versions enable W303 by default.
+CFLAGS += -wcd=303
+# -5s  :  Pentium stack calling conventions.
+# -5r  :  Pentium register calling conventions.
+CFLAGS+= -5s
+
+.SUFFIXES:
+.SUFFIXES: .obj .c
+
+AOUT=xmp.exe
+COMPILE=$(CC) $(CFLAGS) $(CPPFLAGS) $(INCLUDES)
+
+OBJ = commands.obj delay.obj getopt_long.obj info.obj main.obj options.obj read_config.obj sound.obj sound_aiff.obj sound_file.obj sound_null.obj sound_wav.obj terminal.obj
+
+all: $(AOUT)
+
+$(AOUT): $(OBJ) $(LIBXMP)
+	wlink N $(AOUT) SYS $(SYSTEM) OP QUIET LIBR {$(LIBS)} F {$(OBJ)}
+
+.c: src;src/dos
+.c.obj:
+	$(COMPILE) -fo=$^@ $<
+
+distclean: clean .symbolic
+	rm -f $(AOUT) *.err
+clean: .symbolic
+	rm -f *.obj