diff --git a/.github/workflows/build-on-pull-request.yml b/.github/workflows/build-on-pull-request.yml
index f5477d191..e121aaca5 100644
--- a/.github/workflows/build-on-pull-request.yml
+++ b/.github/workflows/build-on-pull-request.yml
@@ -33,6 +33,73 @@ jobs:
       - name: Test that the samples can be built.
         shell: bash
         run: make -j2 samples
+      - name: Test that the targettest programs can be built.
+        shell: bash
+        run: |
+            make SYS=c64 -C targettest all
+            make SYS=c64 -C targettest clean
+            make SYS=apple2 -C targettest
+            make SYS=apple2 -C targettest clean
+            make SYS=apple2enh -C targettest
+            make SYS=apple2enh -C targettest clean
+            make SYS=atari -C targettest
+            make SYS=atari -C targettest clean
+            make SYS=atarixl -C targettest
+            make SYS=atarixl -C targettest clean
+            # make SYS=atari2600 -C targettest
+            # make SYS=atari2600 -C targettest clean
+            # make SYS=atari5200 -C targettest
+            # make SYS=atari5200 -C targettest clean
+            # make SYS=atmos -C targettest
+            # make SYS=atmos -C targettest clean
+            # make SYS=bbc -C targettest
+            # make SYS=bbc -C targettest clean
+            # make SYS=c128 -C targettest
+            # make SYS=c128 -C targettest clean
+            # make SYS=c16 -C targettest
+            # make SYS=c16 -C targettest clean
+            make SYS=c64 -C targettest
+            make SYS=c64 -C targettest clean
+            # make SYS=cbm510 -C targettest
+            # make SYS=cbm510 -C targettest clean
+            # make SYS=cbm610 -C targettest
+            # make SYS=cbm610 -C targettest clean
+            # make SYS=creativision -C targettest
+            # make SYS=creativision -C targettest clean
+            # make SYS=cx16 -C targettest
+            # make SYS=cx16 -C targettest clean
+            # make SYS=gamate -C targettest
+            # make SYS=gamate -C targettest clean
+            # make SYS=geos-apple -C targettest
+            # make SYS=geos-apple -C targettest clean
+            # make SYS=geos-cbm -C targettest
+            # make SYS=geos-cbm -C targettest clean
+            # make SYS=lunix -C targettest
+            # make SYS=lunix -C targettest clean
+            # make SYS=lynx -C targettest
+            # make SYS=lynx -C targettest clean
+            # make SYS=nes -C targettest
+            # make SYS=nes -C targettest clean
+            # make SYS=osic1p -C targettest
+            # make SYS=osic1p -C targettest clean
+            # make SYS=pce -C targettest
+            # make SYS=pce -C targettest clean
+            # make SYS=pet -C targettest
+            # make SYS=pet -C targettest clean
+            # make SYS=plus4 -C targettest
+            # make SYS=plus4 -C targettest clean
+            # make SYS=sim6502 -C targettest
+            # make SYS=sim6502 -C targettest clean
+            # make SYS=sim65c02 -C targettest
+            # make SYS=sim65c02 -C targettest clean
+            # make SYS=supervision -C targettest
+            # make SYS=supervision -C targettest clean
+            # make SYS=sym1 -C targettest
+            # make SYS=sym1 -C targettest clean
+            # make SYS=telestrat -C targettest
+            # make SYS=telestrat -C targettest clean
+            make SYS=vic20 -C targettest
+            make SYS=vic20 -C targettest clean
       - name: Build the document files.
         shell: bash
         run: make -j2 doc
@@ -60,3 +127,8 @@ jobs:
 
       - name: Build app (release)
         run: msbuild src\cc65.sln -t:rebuild -property:Configuration=Release
+
+# TODO: fix tergettest Makefile for all currently commented out targets
+# TODO: build targettest cbm subdir for all cbm targets
+# TODO: build targettest atari subdir for all atari targets
+# TODO: build targettest apple2 subdir for all apple2 targets
diff --git a/asminc/pet.inc b/asminc/pet.inc
index d165bb336..ee96d378c 100644
--- a/asminc/pet.inc
+++ b/asminc/pet.inc
@@ -50,7 +50,6 @@ PET_2000        = $CA
 PET_3000        = $FC
 PET_4000        = $FD
 
-
 ;----------------------------------------------------------------------------
 ; Vector and other locations
 
@@ -59,7 +58,25 @@ BRKVec          := $0092
 NMIVec          := $0094
 
 ; ---------------------------------------------------------------------------
-; I/O: 6522 VIA2
+; I/O: 6520 PIA1
+
+PIA1            := $E810        ; PIA1 base address
+PIA1_PORTA      := PIA1+$0      ; Port A (PA) and data direction register A (DDRA)
+PIA1_PACTL      := PIA1+$1      ; Port A control register (CRA)
+PIA1_PORTB      := PIA1+$2      ; Port B (PB) and data direction register B (DDRB)
+PIA1_PBCTL      := PIA1+$3      ; Port B control register (CRB)
+
+; ---------------------------------------------------------------------------
+; I/O: 6520 PIA2
+
+PIA2            := $E820        ; PIA2 base address
+PIA2_PORTA      := PIA2+$0      ; Port A (PA) and data direction register A (DDRA)
+PIA2_PACTL      := PIA2+$1      ; Port A control register (CRA)
+PIA2_PORTB      := PIA2+$2      ; Port B (PB) and data direction register B (DDRB)
+PIA2_PBCTL      := PIA2+$3      ; Port B control register (CRB)
+
+; ---------------------------------------------------------------------------
+; I/O: 6522 VIA
 
 VIA             := $E840        ; VIA base address
 VIA_PB          := VIA+$0       ; Port register B
diff --git a/doc/atari.sgml b/doc/atari.sgml
index 85dcaaf5e..ff41d0bb4 100644
--- a/doc/atari.sgml
+++ b/doc/atari.sgml
@@ -726,6 +726,11 @@ for sectors 1 to 3, regardless of the type of diskette.
 The console I/O is speed optimized therefore support for XEP80 hardware
 or f80.com software is missing. Of course you may use stdio.h functions.
 
+<tt/cprintf/ targets a 40 character line. On a 20-column display this has
+the unexpected effect of a blank line after your text. On such displays you can either
+use for example <tt/gotoxy(20,0)/ to target the "next" line, or you can switch to <tt/write()/
+function which does not have this side effect.
+
 
 <sect>Technical details<label id="techdetail"><p>
 
diff --git a/include/string.h b/include/string.h
index 2f5953196..83970493e 100644
--- a/include/string.h
+++ b/include/string.h
@@ -78,6 +78,7 @@ int __fastcall__ stricmp (const char* s1, const char* s2);    /* DOS/Windows */
 int __fastcall__ strcasecmp (const char* s1, const char* s2); /* Same for Unix */
 int __fastcall__ strnicmp (const char* s1, const char* s2, size_t count);     /* DOS/Windows */
 int __fastcall__ strncasecmp (const char* s1, const char* s2, size_t count);  /* Same for Unix */
+size_t __fastcall__ strnlen (const char* s, size_t maxlen);     /* POSIX.1-2008 */
 char* __fastcall__ strlwr (char* s);
 char* __fastcall__ strlower (char* s);
 char* __fastcall__ strupr (char* s);
diff --git a/libsrc/common/strnlen.s b/libsrc/common/strnlen.s
new file mode 100644
index 000000000..eb2c16006
--- /dev/null
+++ b/libsrc/common/strnlen.s
@@ -0,0 +1,54 @@
+; size_t __fastcall__ strnlen (const char* s, size_t maxlen);
+
+.export     _strnlen
+.import     popax
+.importzp   ptr1, tmp1, tmp2, tmp3, tmp4
+
+.proc _strnlen
+        ; Get maximum length.
+        tay
+        iny
+        sty     tmp3
+        inx
+        stx     tmp4
+
+        ; Fetch string pointer.
+        jsr     popax
+        sta     ptr1
+        stx     ptr1+1
+
+        ; Clear return value.
+        ldy     #0
+        sty     tmp1
+        sty     tmp2
+
+
+        ;;; Loop over string.
+        ; Decrement maximum length.
+next:   dec     tmp3
+        bne     l2
+        dec     tmp4
+        beq     done
+l2:
+
+        lda     (ptr1),y
+        beq     done
+
+        ; Step to next character.
+        iny
+        bne     l1
+        inc     ptr1+1
+l1:
+
+        ; Increment return value.
+        inc     tmp1
+        bne     next
+        inc     tmp2
+
+        bne     next        ; (jmp)
+
+
+done:   lda     tmp1
+        ldx     tmp2
+        rts
+.endproc
diff --git a/src/sim65/paravirt.c b/src/sim65/paravirt.c
index e73bd3400..db4120326 100644
--- a/src/sim65/paravirt.c
+++ b/src/sim65/paravirt.c
@@ -105,7 +105,7 @@ static void SetAX (CPURegs* Regs, unsigned Val)
 
 static unsigned char Pop (CPURegs* Regs)
 {
-    return MemReadByte (0x0100 + ++Regs->SP);
+    return MemReadByte (0x0100 + (++Regs->SP & 0xFF));
 }
 
 
@@ -317,6 +317,8 @@ void ParaVirtInit (unsigned aArgStart, unsigned char aSPAddr)
 void ParaVirtHooks (CPURegs* Regs)
 /* Potentially execute paravirtualization hooks */
 {
+    unsigned lo;
+
     /* Check for paravirtualization address range */
     if (Regs->PC <  PARAVIRT_BASE ||
         Regs->PC >= PARAVIRT_BASE + sizeof (Hooks) / sizeof (Hooks[0])) {
@@ -327,5 +329,6 @@ void ParaVirtHooks (CPURegs* Regs)
     Hooks[Regs->PC - PARAVIRT_BASE] (Regs);
 
     /* Simulate RTS */
-    Regs->PC = Pop(Regs) + (Pop(Regs) << 8) + 1;
+    lo = Pop (Regs);
+    Regs->PC = lo + (Pop (Regs) << 8) + 1;
 }
diff --git a/targettest/Makefile b/targettest/Makefile
index f3694335c..8207fc560 100644
--- a/targettest/Makefile
+++ b/targettest/Makefile
@@ -122,6 +122,44 @@ DISK_atarixl   = testcode.atr
 
 .PRECIOUS: %.o
 
+LDFLAGS=
+ifeq ($(SYS),c64)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),c128)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),c16)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),cbm510)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),cbm610)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),cx16)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),geos-cbm)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),lunix)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),pet)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),pet-overlay)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),plus4)
+	LDFLAGS+=-Ln $@.lbl
+endif
+ifeq ($(SYS),vic20)
+	LDFLAGS+=-Ln $@.lbl
+endif
+
 .o:
 ifeq ($(SYS),vic20)
 	$(LD) $(LDFLAGS_$(@F)_$(SYS)) $(LDFLAGS) -o $@ -C vic20-32k.cfg -m $@.map $^ $(SYS).lib
@@ -160,6 +198,7 @@ EXELIST_c64 = \
 	scanf-test \
 	ser-test \
 	strdup-test \
+	strnlen \
 	stroserror-test \
 	strqtok-test \
 	tinyshell \
@@ -190,6 +229,7 @@ EXELIST_vic20 = \
 	rename-test \
 	scanf-test \
 	strdup-test \
+	strnlen \
 	stroserror-test \
 	strqtok-test \
 	tinyshell \
@@ -222,6 +262,7 @@ EXELIST_apple2 = \
 	seek \
 	ser-test \
 	strdup-test \
+	strnlen \
 	stroserror-test \
 	strqtok-test \
 	tinyshell \
@@ -257,6 +298,7 @@ EXELIST_atari = \
 	seek \
 	ser-test \
 	strdup-test \
+	strnlen \
 	stroserror-test \
 	strqtok-test \
 	tinyshell \
@@ -292,6 +334,7 @@ all: testcode
 	make -C cbm SYS=$(SYS)
 	make -C gamate
 	make -C pce
+	make -C sym1
 
 # --------------------------------------------------------------------------
 # some programs link against getsp.o
@@ -399,3 +442,4 @@ clean: mostlyclean
 	make -C cbm SYS=$(SYS) clean
 	make -C gamate clean
 	make -C pce clean
+	make -C sym1 clean
diff --git a/targettest/accelerator/Makefile b/targettest/accelerator/Makefile
index 527b13f33..90871f20c 100644
--- a/targettest/accelerator/Makefile
+++ b/targettest/accelerator/Makefile
@@ -20,10 +20,10 @@ ifdef CC65_HOME
   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)
+  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 \
diff --git a/targettest/apple2/Makefile b/targettest/apple2/Makefile
index f8167b47c..15a4075af 100644
--- a/targettest/apple2/Makefile
+++ b/targettest/apple2/Makefile
@@ -23,10 +23,10 @@ ifdef CC65_HOME
   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)
+  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: hgrshow hgrtest dhgrshow
diff --git a/targettest/atari/Makefile b/targettest/atari/Makefile
index 18ddf55ce..05388ddd7 100644
--- a/targettest/atari/Makefile
+++ b/targettest/atari/Makefile
@@ -21,10 +21,10 @@ ifdef CC65_HOME
   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)
+  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 \
diff --git a/targettest/atari5200/Makefile b/targettest/atari5200/Makefile
index 3a8114975..532bb815e 100644
--- a/targettest/atari5200/Makefile
+++ b/targettest/atari5200/Makefile
@@ -21,10 +21,10 @@ ifdef CC65_HOME
   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)
+  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
diff --git a/targettest/cbm/Makefile b/targettest/cbm/Makefile
index 298f80d62..3a4eff86f 100644
--- a/targettest/cbm/Makefile
+++ b/targettest/cbm/Makefile
@@ -24,19 +24,27 @@ ifdef CC65_HOME
   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)
+  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: petscii.prg cbmdir-test.prg
 
+ifeq ($(SYS),c64)
 petscii.prg: petscii.c
 	$(CL) -t $(SYS) -O -o petscii.prg petscii.c
+else
+petscii.prg:
+endif
 
 cbmdir-test.prg: cbmdir-test.c
+ifeq ($(SYS),vic20)
+	$(CL) -t $(SYS) -C vic20-32k.cfg -Oris -o $@ $<
+else
 	$(CL) -t $(SYS) -Oris -o $@ $<
+endif
 
 clean:
-	@$(DEL) petscii.prg cbmdir-test.prg 2>$(NULLDEV)
+	@$(DEL) *.lbl petscii.prg cbmdir-test.prg 2>$(NULLDEV)
diff --git a/targettest/gamate/Makefile b/targettest/gamate/Makefile
index a14b8a854..69ac30dc5 100644
--- a/targettest/gamate/Makefile
+++ b/targettest/gamate/Makefile
@@ -21,10 +21,10 @@ ifdef CC65_HOME
   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)
+  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
diff --git a/targettest/gamate/ctest.c b/targettest/gamate/ctest.c
index bff3f5986..9acbe94cd 100644
--- a/targettest/gamate/ctest.c
+++ b/targettest/gamate/ctest.c
@@ -7,7 +7,7 @@ unsigned char y = 0;
 unsigned char x = 0;
 unsigned short n;
 
-int main(int argc, char *argv[])
+void main(void)
 {
     clrscr();
     gotoxy(0,0);cputs("Gamate C-Test");
@@ -47,6 +47,4 @@ int main(int argc, char *argv[])
         (*((unsigned char*)LCD_YPOS)) = y;
 
     }
-
-    return 0;
 }
diff --git a/targettest/heaptest.c b/targettest/heaptest.c
index 560694bee..e3a21eaa6 100644
--- a/targettest/heaptest.c
+++ b/targettest/heaptest.c
@@ -6,7 +6,7 @@
 
 
 
-static unsigned char* V[256];
+static char* V[256];
 
 
 
@@ -17,7 +17,7 @@ static char* Alloc (void)
     unsigned char Size = (((unsigned char)rand()) & 0x7F) + 1;
 
     /* Allocate memory */
-    unsigned char* P = malloc (Size);
+    char* P = malloc (Size);
 
     /* Set the string to a defined value. We use the size, since this will
     ** also allow us to retrieve it later.
@@ -33,7 +33,7 @@ static char* Alloc (void)
 
 
 
-static void Free (unsigned char* P)
+static void Free (char* P)
 /* Check a memory block and free it */
 {
     unsigned char I;
diff --git a/targettest/pce/Makefile b/targettest/pce/Makefile
index f91f0eed8..695fed0a5 100644
--- a/targettest/pce/Makefile
+++ b/targettest/pce/Makefile
@@ -21,10 +21,10 @@ ifdef CC65_HOME
   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)
+  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
diff --git a/targettest/strdup-test.c b/targettest/strdup-test.c
index 2fcc9816f..8e7ae87d8 100644
--- a/targettest/strdup-test.c
+++ b/targettest/strdup-test.c
@@ -5,7 +5,7 @@
 
 #include <_heap.h>
 
-static unsigned char* V[256];
+static char* V[256];
 
 static void ShowInfo (void)
 /* Show heap info */
diff --git a/targettest/strnlen.c b/targettest/strnlen.c
new file mode 100644
index 000000000..ac39f2396
--- /dev/null
+++ b/targettest/strnlen.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+const char * str = "0123456789";
+
+void
+check (size_t result, size_t expected)
+{
+    if (result != expected) {
+        printf ("Expected strnlen() to return %u, got %u.\n",
+                expected, result);
+        exit (EXIT_FAILURE);
+    }
+}
+
+int
+main (void)
+{
+    size_t  maxlen = strlen (str);
+    size_t  result;
+    size_t  expected;
+
+    for (expected = 0; expected < maxlen; expected++)
+        check (strnlen (str, expected), expected);
+
+    check (strnlen (str, maxlen << 1), maxlen);
+
+    printf ("strnlen() OK.\n");
+
+    return EXIT_SUCCESS;
+}
diff --git a/targettest/sym1/Makefile b/targettest/sym1/Makefile
index 23742f6d1..8e469a599 100644
--- a/targettest/sym1/Makefile
+++ b/targettest/sym1/Makefile
@@ -20,10 +20,10 @@ ifdef CC65_HOME
   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)
+  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: symHello.bin symTiny.bin symDisplay.bin symIO.bin symNotepad.bin
diff --git a/targettest/tinyshell.c b/targettest/tinyshell.c
index c83bd14e8..71e9b56e3 100644
--- a/targettest/tinyshell.c
+++ b/targettest/tinyshell.c
@@ -60,13 +60,13 @@ extern unsigned int getsp(void);  /* comes from getsp.s */
 static unsigned char verbose;
 static unsigned char terminate;
 static unsigned char cmd;
-static unsigned char *cmd_asc, *arg1, *arg2, *arg3, *args;  /* 'args': everything after command */
-static unsigned char keyb_buf[KEYB_BUFSZ + 1];
-static unsigned char keyb_buf2[KEYB_BUFSZ + 1];
+static char *cmd_asc, *arg1, *arg2, *arg3, *args;  /* 'args': everything after command */
+static char keyb_buf[KEYB_BUFSZ + 1];
+static char keyb_buf2[KEYB_BUFSZ + 1];
 static size_t cpbuf_sz = 4096;
 
 struct cmd_table {
-    unsigned char *name;
+    char *name;
     unsigned char code;
 } cmd_table[] = {
     { "help",  CMD_HELP },
@@ -196,7 +196,7 @@ static void cmd_help(void)
 static void cmd_ls(void)
 {
     DIR *dir;
-    unsigned char *arg;
+    char *arg;
     struct dirent *dirent;
 #ifdef __ATARI__
     char need_free = 0;
@@ -356,7 +356,7 @@ static void cmd_rename(void)
 
 static void cmd_exec(void)
 {
-    unsigned char *progname, *arguments;
+    char *progname, *arguments;
 
     progname = strtok(args, " \t\n");
     if (! progname) {
@@ -373,7 +373,7 @@ static void cmd_exec(void)
 static void cmd_copy(void)
 {
     int srcfd = -1, dstfd = -1;
-    unsigned char *buf;
+    char *buf;
     int readsz, writesz;
 
     if (!arg2 || arg3) {