diff --git a/common/zlib/Makefile.riscos b/common/zlib/Makefile.riscos
new file mode 100644
index 0000000..d97f449
--- /dev/null
+++ b/common/zlib/Makefile.riscos
@@ -0,0 +1,151 @@
+# Project:   zlib_1_03
+# Patched for zlib 1.1.2 rw@shadow.org.uk 19980430
+# test works out-of-the-box, installs `somewhere' on demand
+
+# Toolflags:
+CCflags = -c -depend !Depend -IC: -g -throwback  -DRISCOS  -fah 
+C++flags = -c -depend !Depend -IC: -throwback
+Linkflags = -aif -c++ -o $@ 
+ObjAsmflags = -throwback -NoCache -depend !Depend
+CMHGflags = 
+LibFileflags = -c -l -o $@ 
+Squeezeflags = -o $@
+
+# change the line below to where _you_ want the library installed.
+libdest = lib:zlib
+
+# Final targets:
+@.lib:   @.o.adler32 @.o.compress @.o.crc32 @.o.deflate @.o.gzio \
+        @.o.infblock @.o.infcodes @.o.inffast @.o.inflate @.o.inftrees @.o.infutil @.o.trees \
+        @.o.uncompr @.o.zutil 
+        LibFile $(LibFileflags) @.o.adler32 @.o.compress @.o.crc32 @.o.deflate \
+        @.o.gzio @.o.infblock @.o.infcodes @.o.inffast @.o.inflate @.o.inftrees @.o.infutil \
+        @.o.trees @.o.uncompr @.o.zutil 
+test:   @.minigzip @.example @.lib
+	@copy @.lib @.libc  A~C~DF~L~N~P~Q~RS~TV
+	@echo running tests: hang on.
+	@/@.minigzip -f -9 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -f -1 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -h -9 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -h -1 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -9 libc
+	@/@.minigzip -d libc-gz
+	@/@.minigzip -1 libc
+	@/@.minigzip -d libc-gz
+	@diff @.lib @.libc
+	@echo that should have reported '@.lib and @.libc identical' if you have diff.
+	@/@.example @.fred @.fred
+	@echo that will have given lots of hello!'s.
+
+@.minigzip:   @.o.minigzip @.lib C:o.Stubs 
+        Link $(Linkflags) @.o.minigzip @.lib C:o.Stubs 
+@.example:   @.o.example @.lib C:o.Stubs 
+        Link $(Linkflags) @.o.example @.lib C:o.Stubs
+
+install: @.lib
+	cdir $(libdest)
+	cdir $(libdest).h
+	@copy @.h.zlib $(libdest).h.zlib A~C~DF~L~N~P~Q~RS~TV
+	@copy @.h.zconf $(libdest).h.zconf A~C~DF~L~N~P~Q~RS~TV
+	@copy @.lib $(libdest).lib  A~C~DF~L~N~P~Q~RS~TV
+	@echo okay, installed zlib in $(libdest)
+
+clean:; remove @.minigzip
+	remove @.example
+	remove @.libc
+	-wipe @.o.* F~r~cV
+	remove @.fred
+
+# User-editable dependencies:
+.c.o:
+        cc $(ccflags) -o $@ $<
+
+# Static dependencies:
+
+# Dynamic dependencies:
+o.example:	c.example
+o.example:	h.zlib
+o.example:	h.zconf
+o.minigzip:	c.minigzip
+o.minigzip:	h.zlib
+o.minigzip:	h.zconf
+o.adler32:	c.adler32
+o.adler32:	h.zlib
+o.adler32:	h.zconf
+o.compress:	c.compress
+o.compress:	h.zlib
+o.compress:	h.zconf
+o.crc32:	c.crc32
+o.crc32:	h.zlib
+o.crc32:	h.zconf
+o.deflate:	c.deflate
+o.deflate:	h.deflate
+o.deflate:	h.zutil
+o.deflate:	h.zlib
+o.deflate:	h.zconf
+o.gzio:	c.gzio
+o.gzio:	h.zutil
+o.gzio:	h.zlib
+o.gzio:	h.zconf
+o.infblock:	c.infblock
+o.infblock:	h.zutil
+o.infblock:	h.zlib
+o.infblock:	h.zconf
+o.infblock:	h.infblock
+o.infblock:	h.inftrees
+o.infblock:	h.infcodes
+o.infblock:	h.infutil
+o.infcodes:	c.infcodes
+o.infcodes:	h.zutil
+o.infcodes:	h.zlib
+o.infcodes:	h.zconf
+o.infcodes:	h.inftrees
+o.infcodes:	h.infblock
+o.infcodes:	h.infcodes
+o.infcodes:	h.infutil
+o.infcodes:	h.inffast
+o.inffast:	c.inffast
+o.inffast:	h.zutil
+o.inffast:	h.zlib
+o.inffast:	h.zconf
+o.inffast:	h.inftrees
+o.inffast:	h.infblock
+o.inffast:	h.infcodes
+o.inffast:	h.infutil
+o.inffast:	h.inffast
+o.inflate:	c.inflate
+o.inflate:	h.zutil
+o.inflate:	h.zlib
+o.inflate:	h.zconf
+o.inflate:	h.infblock
+o.inftrees:	c.inftrees
+o.inftrees:	h.zutil
+o.inftrees:	h.zlib
+o.inftrees:	h.zconf
+o.inftrees:	h.inftrees
+o.inftrees:	h.inffixed
+o.infutil:	c.infutil
+o.infutil:	h.zutil
+o.infutil:	h.zlib
+o.infutil:	h.zconf
+o.infutil:	h.infblock
+o.infutil:	h.inftrees
+o.infutil:	h.infcodes
+o.infutil:	h.infutil
+o.trees:	c.trees
+o.trees:	h.deflate
+o.trees:	h.zutil
+o.trees:	h.zlib
+o.trees:	h.zconf
+o.trees:	h.trees
+o.uncompr:	c.uncompr
+o.uncompr:	h.zlib
+o.uncompr:	h.zconf
+o.zutil:	c.zutil
+o.zutil:	h.zutil
+o.zutil:	h.zlib
+o.zutil:	h.zconf