diff --git a/6502/C64/Makefile b/6502/C64/Makefile
index 0e45df6..0fb31c6 100644
--- a/6502/C64/Makefile
+++ b/6502/C64/Makefile
@@ -3,6 +3,9 @@
 # the file format conversion tools from the tools/ subdir of
 # https://github.com/pzembrod/cc64 to be installed.
 
+# VERSION=volksforth83
+VERSION=vf-latest
+
 vf_blk_d64_files = $(wildcard disks/*.d64)
 vf_blk_fth_files = $(patsubst %.d64, %.fth, $(vf_blk_d64_files))
 
@@ -16,6 +19,7 @@ vf_blk_fth: $(vf_blk_fth_files)
 
 clean:
 	rm -f cbmfiles/*.fr cbmfiles/*.fth cbmfiles/*.log *.log *.result
+	rm -f cbmfiles/c??-testbase
 
 
 # Convenience targets
@@ -36,29 +40,35 @@ run-testbase16: emulator/testbase16.T64
 
 # Targetcompiler targets
 
-cbmfiles/tcbase: emulator/testbase.T64 emulator/build-tcbase.sh \
+cbmfiles/tcbase: emulator/c64-testbase.T64 emulator/build-tcbase.sh \
     disks/vforth4_2.d64  disks/tc38q.d64 cbmfiles/mk-tcbase.fth
 	emulator/build-tcbase.sh
 
-cbmfiles/vf83-c64: emulator/tcbase.T64 emulator/build-c64forth.sh \
+cbmfiles/c64-vf-latest: emulator/tcbase.T64 emulator/build-c64forth.sh \
     disks/vforth4_2.d64  disks/tc38q.d64 cbmfiles/mk-c64forth.fth
 	emulator/build-c64forth.sh
 
+# Temp stopgap to fit c16 into default use of VERSION=vf-latest
+# until we have a proper c16 targetcompiler rule.
+# Missing part: Moving the target machine definition from vforth4_2.d64
+# screen 9 to somewhere more flexible. Likely two .fth files.
+cbmfiles/c16-vf-latest: cbmfiles/c16-volksforth83
+	cp $< $@
 
 # Core test targets
 
-test-c64.result: emulator/testbase.T64 $(test_files_petscii) \
+test-c64.result: emulator/c64-testbase.T64 $(test_files_petscii) \
     emulator/run-in-vice.sh tests/evaluate-test.sh tests/test-c64.golden
 	rm -f test-c64.log test-c64.result
-	emulator/run-in-vice.sh testbase \
+	emulator/run-in-vice.sh c64-testbase \
 	  "include run-vf-tests.fth\n1234567890\ndos s0:notdone\n"
 	petscii2ascii cbmfiles/test.log test-c64.log
 	tests/evaluate-test.sh test-c64
 
-test-c16.result: emulator/testbase16.T64 $(test_files_petscii) \
+test-c16.result: emulator/c16-testbase.T64 $(test_files_petscii) \
     emulator/run-in-vice.sh tests/evaluate-test.sh tests/test-c16.golden
 	rm -f test-c16.log test-c16.result
-	VICE=xplus4 emulator/run-in-vice.sh testbase16 \
+	VICE=xplus4 emulator/run-in-vice.sh c16-testbase \
 	  "include run-vf-tests.fth\n1234567890\ndos s0:notdone\n"
 	petscii2ascii cbmfiles/test.log test-c16.log
 	tests/evaluate-test.sh test-c16
@@ -72,13 +82,13 @@ cbmfiles/devenv: emulator/run-in-vice.sh emulator/build-devenv.sh \
      disks/vforth4_1.d64  disks/vforth4_3.d64  disks/file-words.d64
 	emulator/build-devenv.sh
 
-cbmfiles/testbase: emulator/run-in-vice.sh emulator/build-testbase.sh \
-    emulator/c64-volksforth83.T64 disks/file-words.d64
-	emulator/build-testbase.sh
+cbmfiles/c64-testbase: emulator/run-in-vice.sh emulator/build-testbase.sh \
+    emulator/c64-$(VERSION).T64 disks/file-words.d64
+	emulator/build-testbase.sh c64 $(VERSION)
 
-cbmfiles/testbase16: emulator/run-in-vice.sh emulator/build-testbase.sh \
-    emulator/c16-volksforth83.T64 disks/file-words.d64
-	emulator/build-testbase16.sh
+cbmfiles/c16-testbase: emulator/run-in-vice.sh emulator/build-testbase.sh \
+    emulator/c16-$(VERSION).T64 disks/file-words.d64
+	VICE=xplus4 emulator/build-testbase.sh c16 $(VERSION)
 
 
 # Generic T64 tape image rule
diff --git a/6502/C64/cbmfiles/testbase b/6502/C64/cbmfiles/c64-vf-latest
similarity index 88%
rename from 6502/C64/cbmfiles/testbase
rename to 6502/C64/cbmfiles/c64-vf-latest
index 4eca2cb..ec518dd 100644
Binary files a/6502/C64/cbmfiles/testbase and b/6502/C64/cbmfiles/c64-vf-latest differ
diff --git a/6502/C64/cbmfiles/tcbase b/6502/C64/cbmfiles/tcbase
new file mode 100644
index 0000000..0ff1c57
Binary files /dev/null and b/6502/C64/cbmfiles/tcbase differ
diff --git a/6502/C64/cbmfiles/testbase16 b/6502/C64/cbmfiles/testbase16
deleted file mode 100644
index c3a1241..0000000
Binary files a/6502/C64/cbmfiles/testbase16 and /dev/null differ
diff --git a/6502/C64/emulator/build-c64forth.sh b/6502/C64/emulator/build-c64forth.sh
index 9d3992a..cc0a10a 100755
--- a/6502/C64/emulator/build-c64forth.sh
+++ b/6502/C64/emulator/build-c64forth.sh
@@ -4,10 +4,10 @@ set -e
 emulatordir="$(dirname "${BASH_SOURCE[0]}")"
 basedir="$(realpath --relative-to="$PWD" "${emulatordir}/..")"
 
-rm -f "${basedir}/cbmfiles/vf83-c64"
+rm -f "${basedir}/cbmfiles/c64-vf-latest"
 
 keybuf="include mk-c64forth.fth\n\
-save-target vf83-c64\ndos s0:notdone\n"
+save-target c64-vf-latest\ndos s0:notdone\n"
 
 DISK9=vforth4_2 DISK10=tc38q "${emulatordir}/run-in-vice.sh" \
   "tcbase" "${keybuf}"
diff --git a/6502/C64/emulator/build-tcbase.sh b/6502/C64/emulator/build-tcbase.sh
index 6762203..01cac95 100755
--- a/6502/C64/emulator/build-tcbase.sh
+++ b/6502/C64/emulator/build-tcbase.sh
@@ -10,4 +10,4 @@ keybuf="2 drive 4 load\ninclude mk-tcbase.fth\n\
 savesystem tcbase\ndos s0:notdone\n"
 
 DISK9=vforth4_2 DISK10=tc38q "${emulatordir}/run-in-vice.sh" \
-  "testbase" "${keybuf}"
+  "c64-testbase" "${keybuf}"
diff --git a/6502/C64/emulator/build-testbase.sh b/6502/C64/emulator/build-testbase.sh
index a53cb4b..7e5c59e 100755
--- a/6502/C64/emulator/build-testbase.sh
+++ b/6502/C64/emulator/build-testbase.sh
@@ -4,13 +4,18 @@ set -e
 emulatordir="$(dirname "${BASH_SOURCE[0]}")"
 basedir="$(realpath --relative-to="$PWD" "${emulatordir}/..")"
 
-rm -f "${basedir}/cbmfiles/testbase"
+platform="$1"
+version="$2"
+source="${platform}-${version}"
+target="${platform}-testbase"
+
+rm -f "${basedir}/cbmfiles/${target}"
 
 # load savesystem w/o editor from file-words.d64 block 20.
 # load include and dos from file-words.d64 block 10.
 # savesystem and then scratch file notdone to exit emulator.
 keybuf="3 drive 20 load\n3 drive 10 load\n\
-savesystem testbase\ndos s0:notdone\n"
+savesystem ${target}\ndos s0:notdone\n"
 
 DISK11=file-words "${emulatordir}/run-in-vice.sh" \
-  "c64-volksforth83" "${keybuf}"
+  "${source}" "${keybuf}"