diff --git a/examples/pgztest/build.sh b/examples/pgztest/build.sh
index 6fb15f9..4027943 100755
--- a/examples/pgztest/build.sh
+++ b/examples/pgztest/build.sh
@@ -33,7 +33,7 @@ PATH=${LLVM}/bin:${PATH}
 
 echo "__f256_start = ${START};" > ${SETTINGS}
 
-CLANG="mos-f256k-clang -I${F256}/include -I${F256}/f256lib -O3"
+CLANG="mos-f256k-clang -I${F256}/include -I${F256}/f256lib -Wall -O3"
 
 ${CLANG} -c ${F256}/f256lib/f256.c
 ${CLANG} -c ${PROJECT}.c
diff --git a/f256lib/file.c b/f256lib/file.c
index dc73da0..e2d4583 100644
--- a/f256lib/file.c
+++ b/f256lib/file.c
@@ -35,7 +35,7 @@ static char _dirStream[MAX_DRIVES];
 static bool     findName(char *name, int16_t *offset);
 static int16_t  kernelRead(uint8_t fd, void *buf, uint16_t nbytes);
 static int16_t  kernelWrite(uint8_t fd, void *buf, uint16_t nbytes);
-static char    *pathWithoutDrive(char *path, char *drive);
+static char    *pathWithoutDrive(char *path, byte *drive);
 
 
 #pragma push_macro("close")
@@ -87,7 +87,7 @@ int16_t *fileOpen(char *fname, char *mode) {
 	int16_t  ret = 0;
 	uint8_t  m   = 0;  // Default to READ.
 	int16_t *fd;
-	char     drive;
+	byte     drive;
 	char    *c;
 
 	fname = pathWithoutDrive(fname, &drive);
@@ -124,7 +124,7 @@ int16_t *fileOpen(char *fname, char *mode) {
 
 
 char *fileOpenDir(char *name) {
-	char  drive;
+	byte  drive;
 	char  stream;
 	char *dir;
 
@@ -234,9 +234,8 @@ fileDirEntT *fileReadDir(char *dir) {
 
 
 int16_t fileRename(char *name, char *to) {
-	char    drive;
-	char    drive2;
-	char    stream;
+	byte    drive;
+	byte    drive2;
 	int16_t path1;
 	int16_t path2;
 
@@ -261,7 +260,7 @@ int16_t fileRename(char *name, char *to) {
 	kernelArgs->common.buflen = strlen(name);
 	kernelArgs->common.ext = to;
 	kernelArgs->common.extlen = strlen(to);
-	stream = kernelCall(File.Rename);
+	kernelCall(File.Rename);
 	if (kernelError) return -1;
 
 	for (;;) {
@@ -296,14 +295,13 @@ int16_t fileSeek(uint8_t *fd, uint32_t offset, uint8_t whence) {
 
 
 int16_t fileUnlink(char *name) {
-	char drive;
-	char stream;
+	byte drive;
 
 	name = pathWithoutDrive(name, &drive);
 	kernelArgs->file.delete.drive = drive;
 	kernelArgs->common.buf = name;
 	kernelArgs->common.buflen = strlen(name);
-	stream = kernelCall(File.Delete);
+	kernelCall(File.Delete);
 	if (kernelError) return -1;
 
 	for (;;) {
@@ -428,7 +426,7 @@ static int16_t kernelWrite(uint8_t fd, void *buf, uint16_t nbytes) {
 }
 
 
-static char *pathWithoutDrive(char *path, char *drive) {
+static char *pathWithoutDrive(char *path, byte *drive) {
 	*drive = 0;
 
 	if (strlen(path) < 2) return path;
diff --git a/f256lib/text.c b/f256lib/text.c
index 4f788c4..a27a8b3 100644
--- a/f256lib/text.c
+++ b/f256lib/text.c
@@ -198,7 +198,6 @@ void textPrintUInt(uint32_t value){
 
 void textReset(void) {
 	byte  x;
-	byte  y;
 
 	_fcolor  = 15;
 	_bcolor  = 0;