diff --git a/testcode/lib/accelerator/Makefile b/testcode/lib/accelerator/Makefile
index 6b90a9556..f4f651535 100644
--- a/testcode/lib/accelerator/Makefile
+++ b/testcode/lib/accelerator/Makefile
@@ -1,4 +1,30 @@
-CL ?= cl65
+# Just the usual way to find out if we're
+# using cmd.exe to execute make rules.
+ifneq ($(shell echo),)
+  CMD_EXE = 1
+endif
+
+ifdef CMD_EXE
+  NULLDEV = nul:
+  DEL = -del /f
+  RMDIR = rmdir /s /q
+else
+  NULLDEV = /dev/null
+  DEL = $(RM)
+  RMDIR = $(RM) -r
+endif
+
+ifdef CC65_HOME
+  AS = $(CC65_HOME)/bin/ca65
+  CC = $(CC65_HOME)/bin/cc65
+  CL = $(CC65_HOME)/bin/cl65
+  LD = $(CC65_HOME)/bin/ld65
+else
+  AS := $(if $(wildcard ../../../bin/ca65*),../../../bin/ca65,ca65)
+  CC := $(if $(wildcard ../../../bin/cc65*),../../../bin/cc65,cc65)
+  CL := $(if $(wildcard ../../../bin/cl65*),../../../bin/cl65,cl65)
+  LD := $(if $(wildcard ../../../bin/ld65*),../../../bin/ld65,ld65)
+endif
 
 all:	c64-scpu-test.prg c128-scpu-test.prg c64dtv-test.prg \
 	c64-c128-test.prg c128-test.prg chameleon-test.prg \
@@ -27,3 +53,6 @@ c65-test.prg: c65-test.c
 
 turbomaster-test.prg: turbomaster-test.c
 	$(CL) -t c64 turbomaster-test.c -o turbomaster-test.prg
+
+clean:
+	$(RM) *.prg
diff --git a/testcode/lib/apple2/Makefile b/testcode/lib/apple2/Makefile
index 9d551aa62..3ea2463f1 100644
--- a/testcode/lib/apple2/Makefile
+++ b/testcode/lib/apple2/Makefile
@@ -1,7 +1,33 @@
 # For this one see https://applecommander.github.io/
 AC ?= ac.jar
 
-CL ?= cl65
+# Just the usual way to find out if we're
+# using cmd.exe to execute make rules.
+ifneq ($(shell echo),)
+  CMD_EXE = 1
+endif
+
+ifdef CMD_EXE
+  NULLDEV = nul:
+  DEL = -del /f
+  RMDIR = rmdir /s /q
+else
+  NULLDEV = /dev/null
+  DEL = $(RM)
+  RMDIR = $(RM) -r
+endif
+
+ifdef CC65_HOME
+  AS = $(CC65_HOME)/bin/ca65
+  CC = $(CC65_HOME)/bin/cc65
+  CL = $(CC65_HOME)/bin/cl65
+  LD = $(CC65_HOME)/bin/ld65
+else
+  AS := $(if $(wildcard ../../../bin/ca65*),../../../bin/ca65,ca65)
+  CC := $(if $(wildcard ../../../bin/cc65*),../../../bin/cc65,cc65)
+  CL := $(if $(wildcard ../../../bin/cl65*),../../../bin/cl65,cl65)
+  LD := $(if $(wildcard ../../../bin/ld65*),../../../bin/ld65,ld65)
+endif
 
 all: hgr.dsk dhgr.dsk
 
@@ -35,3 +61,8 @@ dhgr.dsk: dhgrshow
 
 dhgrshow: dhgrshow.c
 	$(CL) -Oirs -t apple2enh --start-addr 0x4000 -m dhgrshow.map $^
+
+clean:
+	$(RM) hgr.dsk dhgr.dsk
+	$(RM) hgrshow hgrshow.map	
+	$(RM) hgrtest hgrtest.map
diff --git a/testcode/lib/atari/Makefile b/testcode/lib/atari/Makefile
index e9ec853b8..a34a5f2d9 100644
--- a/testcode/lib/atari/Makefile
+++ b/testcode/lib/atari/Makefile
@@ -1,24 +1,53 @@
 
+# Just the usual way to find out if we're
+# using cmd.exe to execute make rules.
+ifneq ($(shell echo),)
+  CMD_EXE = 1
+endif
+
+ifdef CMD_EXE
+  NULLDEV = nul:
+  DEL = -del /f
+  RMDIR = rmdir /s /q
+else
+  NULLDEV = /dev/null
+  DEL = $(RM)
+  RMDIR = $(RM) -r
+endif
+
+ifdef CC65_HOME
+  AS = $(CC65_HOME)/bin/ca65
+  CC = $(CC65_HOME)/bin/cc65
+  CL = $(CC65_HOME)/bin/cl65
+  LD = $(CC65_HOME)/bin/ld65
+else
+  AS := $(if $(wildcard ../../../bin/ca65*),../../../bin/ca65,ca65)
+  CC := $(if $(wildcard ../../../bin/cc65*),../../../bin/cc65,cc65)
+  CL := $(if $(wildcard ../../../bin/cl65*),../../../bin/cl65,cl65)
+  LD := $(if $(wildcard ../../../bin/ld65*),../../../bin/ld65,ld65)
+endif
+
 all: charmapping.xex defdev.xex displaylist.xex mem.xex multi.xex ostype.xex \
 	scrcode.com sys.xex
 
 charmapping.xex: charmapping.c
-	cl65 -t atari -o charmapping.xex charmapping.c
+	$(CL) -t atari -o charmapping.xex charmapping.c
 defdev.xex: defdev.c
-	cl65 -t atari -o defdev.xex defdev.c
+	$(CL) -t atari -o defdev.xex defdev.c
 displaylist.xex: displaylist.c
-	cl65 -t atari -o displaylist.xex displaylist.c
+	$(CL) -t atari -o displaylist.xex displaylist.c
 mem.xex: mem.c ../getsp.s
-	cl65 -t atari -o mem.xex mem.c ../getsp.s
+	$(CL) -t atari -o mem.xex mem.c ../getsp.s
 multi.xex: multi-xex.s multi-xex.cfg
-	cl65 -t atari -C multi-xex.cfg multi-xex.s -o multi.xex
+	$(CL) -t atari -C multi-xex.cfg multi-xex.s -o multi.xex
 ostype.xex: ostype.c
-	cl65 -t atari -o ostype.xex ostype.c
+	$(CL) -t atari -o ostype.xex ostype.c
 scrcode.com: scrcode.s
-	ca65 -t atari -o scrcode.o scrcode.s
-	ld65 -C atari-asm.cfg -o scrcode.com scrcode.o
+#	ca65 -t atari -o scrcode.o scrcode.s
+#	ld65 -C atari-asm.cfg -o scrcode.com scrcode.o
+	$(CL) -t atari -C atari-asm.cfg -o scrcode.com scrcode.s
 sys.xex: sys.c
-	cl65 -t atari -o sys.xex sys.c
+	$(CL) -t atari -o sys.xex sys.c
 
 clean:
 	$(RM) charmapping.xex
diff --git a/testcode/lib/atari5200/Makefile b/testcode/lib/atari5200/Makefile
new file mode 100644
index 000000000..990ced689
--- /dev/null
+++ b/testcode/lib/atari5200/Makefile
@@ -0,0 +1,36 @@
+
+# Just the usual way to find out if we're
+# using cmd.exe to execute make rules.
+ifneq ($(shell echo),)
+  CMD_EXE = 1
+endif
+
+ifdef CMD_EXE
+  NULLDEV = nul:
+  DEL = -del /f
+  RMDIR = rmdir /s /q
+else
+  NULLDEV = /dev/null
+  DEL = $(RM)
+  RMDIR = $(RM) -r
+endif
+
+ifdef CC65_HOME
+  AS = $(CC65_HOME)/bin/ca65
+  CC = $(CC65_HOME)/bin/cc65
+  CL = $(CC65_HOME)/bin/cl65
+  LD = $(CC65_HOME)/bin/ld65
+else
+  AS := $(if $(wildcard ../../../bin/ca65*),../../../bin/ca65,ca65)
+  CC := $(if $(wildcard ../../../bin/cc65*),../../../bin/cc65,cc65)
+  CL := $(if $(wildcard ../../../bin/cl65*),../../../bin/cl65,cl65)
+  LD := $(if $(wildcard ../../../bin/ld65*),../../../bin/ld65,ld65)
+endif
+
+all: hello
+
+hello: hello.c
+	$(CL) -t atari5200 -o hello hello.c
+	
+clean:
+	$(RM) hello
diff --git a/testcode/lib/gamate/Makefile b/testcode/lib/gamate/Makefile
index 2cf98d189..d4f1b9673 100644
--- a/testcode/lib/gamate/Makefile
+++ b/testcode/lib/gamate/Makefile
@@ -1,14 +1,42 @@
 
+# Just the usual way to find out if we're
+# using cmd.exe to execute make rules.
+ifneq ($(shell echo),)
+  CMD_EXE = 1
+endif
+
+ifdef CMD_EXE
+  NULLDEV = nul:
+  DEL = -del /f
+  RMDIR = rmdir /s /q
+else
+  NULLDEV = /dev/null
+  DEL = $(RM)
+  RMDIR = $(RM) -r
+endif
+
+ifdef CC65_HOME
+  AS = $(CC65_HOME)/bin/ca65
+  CC = $(CC65_HOME)/bin/cc65
+  CL = $(CC65_HOME)/bin/cl65
+  LD = $(CC65_HOME)/bin/ld65
+else
+  AS := $(if $(wildcard ../../../bin/ca65*),../../../bin/ca65,ca65)
+  CC := $(if $(wildcard ../../../bin/cc65*),../../../bin/cc65,cc65)
+  CL := $(if $(wildcard ../../../bin/cl65*),../../../bin/cl65,cl65)
+  LD := $(if $(wildcard ../../../bin/ld65*),../../../bin/ld65,ld65)
+endif
+
 all: audiotest.bin lcdtest.bin ctest.bin
 
 audiotest.bin: audiotest.s
-	../../../bin/cl65 -l audiotest.lst -t gamate -o audiotest.bin audiotest.s
+	$(CL) -l audiotest.lst -t gamate -o audiotest.bin audiotest.s
 lcdtest.bin: lcdtest.s
-	../../../bin/cl65 -l lcdtest.lst -t gamate -o lcdtest.bin lcdtest.s
+	$(CL) -l lcdtest.lst -t gamate -o lcdtest.bin lcdtest.s
 ctest.bin: ctest.c
-	../../../bin/cl65 -l ctest.lst -t gamate -o ctest.bin ctest.c
+	$(CL) -l ctest.lst -t gamate -o ctest.bin ctest.c
 nachtm.bin: nachtm.c
-	../../../bin/cl65 -Os -l nachtm.lst -t gamate -o nachtm.bin nachtm.c
+	$(CL) -Os -l nachtm.lst -t gamate -o nachtm.bin nachtm.c
 	gamate-fixcart nachtm.bin
 
 test1: lcdtest.bin
@@ -21,5 +49,6 @@ testn: nachtm.bin
 	cd ~/Desktop/mame/winmess/ && wine mess.exe gamate -window -skip_gameinfo -cart ~/Desktop/cc65/github/cc65/testcode/lib/gamate/nachtm.bin
 
 clean:
-	rm -f lcdtest.o audiotest.o ctest.o
-	rm -f lcdtest.bin audiotest.bin ctest.bin nachtm.bin
+	$(RM) lcdtest.o audiotest.o ctest.o
+	$(RM) lcdtest.bin audiotest.bin ctest.bin nachtm.bin
+	$(RM) audiotest.lst lcdtest.lst ctest.lst
diff --git a/testcode/lib/pce/Makefile b/testcode/lib/pce/Makefile
index a4a495c9a..0c41778cc 100644
--- a/testcode/lib/pce/Makefile
+++ b/testcode/lib/pce/Makefile
@@ -1,3 +1,32 @@
+
+# Just the usual way to find out if we're
+# using cmd.exe to execute make rules.
+ifneq ($(shell echo),)
+  CMD_EXE = 1
+endif
+
+ifdef CMD_EXE
+  NULLDEV = nul:
+  DEL = -del /f
+  RMDIR = rmdir /s /q
+else
+  NULLDEV = /dev/null
+  DEL = $(RM)
+  RMDIR = $(RM) -r
+endif
+
+ifdef CC65_HOME
+  AS = $(CC65_HOME)/bin/ca65
+  CC = $(CC65_HOME)/bin/cc65
+  CL = $(CC65_HOME)/bin/cl65
+  LD = $(CC65_HOME)/bin/ld65
+else
+  AS := $(if $(wildcard ../../../bin/ca65*),../../../bin/ca65,ca65)
+  CC := $(if $(wildcard ../../../bin/cc65*),../../../bin/cc65,cc65)
+  CL := $(if $(wildcard ../../../bin/cl65*),../../../bin/cl65,cl65)
+  LD := $(if $(wildcard ../../../bin/ld65*),../../../bin/ld65,ld65)
+endif
+
 .PHONY: all clean test
 
 # Size of cartridge to generate.