diff --git a/6502/C64/Makefile b/6502/C64/Makefile
index c8f9662..876f8bd 100644
--- a/6502/C64/Makefile
+++ b/6502/C64/Makefile
@@ -22,10 +22,17 @@ run-devenv: emulator/devenv.T64
 run-testbase: emulator/testbase.T64
 	emulator/run-in-vice.sh testbase
 
-run-tests: emulator/testbase.T64 $(test_files_petscii)
+test: emulator/testbase.T64 $(test_files_petscii)
 	emulator/run-in-vice.sh testbase \
 	  "include run-vf-tests.fth\n"
 
+run-testbase16: emulator/testbase16.T64
+	VICE=xplus4 emulator/run-in-vice.sh testbase16
+
+test16: emulator/testbase.T64 $(test_files_petscii)
+	VICE=xplus4 emulator/run-in-vice.sh testbase16 \
+	  "include run-vf-tests.fth\n"
+
 
 # Rules for building Forth binaries on top of the plain vanilla
 # c64-volksforth83.
@@ -39,6 +46,10 @@ cbmfiles/testbase: emulator/run-in-vice.sh emulator/build-testbase.sh \
     emulator/c64-volksforth83.T64 disks/file-words.d64
 	emulator/build-testbase.sh
 
+cbmfiles/testbase16: emulator/run-in-vice.sh emulator/build-testbase.sh \
+    emulator/c16-volksforth83.T64 disks/file-words.d64
+	emulator/build-testbase16.sh
+
 
 # Generic T64 tape image rule
 
diff --git a/6502/C64/cbmfiles/testbase16 b/6502/C64/cbmfiles/testbase16
new file mode 100644
index 0000000..f2c1e31
Binary files /dev/null and b/6502/C64/cbmfiles/testbase16 differ
diff --git a/6502/C64/emulator/build-testbase16.sh b/6502/C64/emulator/build-testbase16.sh
new file mode 100755
index 0000000..5918d95
--- /dev/null
+++ b/6502/C64/emulator/build-testbase16.sh
@@ -0,0 +1,16 @@
+#!/bin/bash
+set -e
+
+emulatordir="$(dirname "${BASH_SOURCE[0]}")"
+basedir="$(realpath --relative-to="$PWD" "${emulatordir}/..")"
+
+rm -f "${basedir}/cbmfiles/testbase"
+
+# load savesystem w/o editor from file-words.d64 block 20 in drive 11.
+# load include and dos from file-words.d64 block 10 in drive 11.
+# savesystem and then scratch file notdone to exit emulator.
+keybuf="3 drive 20 load\n3 drive 10 load\n\
+savesystem testbase16\ndos s0:notdone\n"
+
+VICE=xplus4 "${emulatordir}/run-in-vice.sh" \
+  "c16-volksforth83" "${keybuf}"
diff --git a/6502/C64/emulator/run-in-vice.sh b/6502/C64/emulator/run-in-vice.sh
index 9ee6192..09a05d5 100755
--- a/6502/C64/emulator/run-in-vice.sh
+++ b/6502/C64/emulator/run-in-vice.sh
@@ -1,6 +1,7 @@
 #!/bin/bash
 set -e
 
+test -n "$VICE" || VICE=x64
 emulatordir="$(realpath --relative-to="$PWD" "$(dirname "${BASH_SOURCE[0]}")")"
 basedir="$(realpath --relative-to="$PWD" "${emulatordir}/..")"
 
@@ -20,7 +21,7 @@ then
   warp="-warp"
 fi
 
-x64 \
+"$VICE" \
   -virtualdev \
   +truedrive \
   -drive8type 1541 \