diff --git a/source/fltkui/fltkui_archive.cpp b/source/fltkui/fltkui_archive.cpp
index 38bc737..77fd7b5 100644
--- a/source/fltkui/fltkui_archive.cpp
+++ b/source/fltkui/fltkui_archive.cpp
@@ -47,9 +47,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "fltkui.h"
 #include "fltkui_archive.h"
 
-static Fl_Double_Window *window;
-static Fl_Select_Browser *browser;
-static char *romfile = NULL;
+static Fl_Double_Window *window{nullptr};
+static Fl_Select_Browser *browser{nullptr};
+static char *romfile{nullptr};
 
 static void fltkui_archive_ok(Fl_Widget *w, long) {
     window->hide();
diff --git a/source/fltkui/fltkui_cheats.cpp b/source/fltkui/fltkui_cheats.cpp
index c93c060..5420105 100644
--- a/source/fltkui/fltkui_cheats.cpp
+++ b/source/fltkui/fltkui_cheats.cpp
@@ -45,11 +45,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace {
 
-NstChtWindow *chtwin = nullptr;
+NstChtWindow *chtwin{nullptr};
 
-Fl_Input *input_desc;
-Fl_Input *input_gg;
-Fl_Input *input_par;
+Fl_Input *input_desc{nullptr};
+Fl_Input *input_gg{nullptr};
+Fl_Input *input_par{nullptr};
 
 }
 
diff --git a/source/fltkui/inputmanager.cpp b/source/fltkui/inputmanager.cpp
index ed714b8..87dce96 100644
--- a/source/fltkui/inputmanager.cpp
+++ b/source/fltkui/inputmanager.cpp
@@ -47,8 +47,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace {
 
-jg_inputstate_t coreinput[5];
-jg_inputinfo_t *inputinfo[5];
+jg_inputstate_t coreinput[5]{};
+jg_inputinfo_t *inputinfo[5]{nullptr};
 
 jg_inputstate_t uistate;
 jg_inputinfo_t uiinfo;
@@ -65,18 +65,18 @@ const int ui_defaults[NDEFS_UI - 1] = {
     0xffbd + 6, 0xffbd + 7, 0xffbd + 8, 'f', 'p', '`', 0xffbd + 9
 };
 
-bool uiprev[NDEFS_UI];
+bool uiprev[NDEFS_UI]{};
 
-uint8_t undef8;
-uint16_t undef16;
+uint8_t undef8{};
+uint16_t undef16{};
 
 constexpr int DEADZONE = 5120;
 constexpr size_t MAXPORTS = 4;
 
-SDL_Joystick *joystick[MAXPORTS];
-int jsports[MAXPORTS];
-int jsiid[MAXPORTS];
-int jstrig[MAXPORTS]{{0}};
+SDL_Joystick *joystick[MAXPORTS]{nullptr};
+int jsports[MAXPORTS]{};
+int jsiid[MAXPORTS]{};
+int jstrig[MAXPORTS]{};
 
 bool conflict{false};
 
diff --git a/source/fltkui/jgmanager.cpp b/source/fltkui/jgmanager.cpp
index bbd91be..b9b3f4b 100644
--- a/source/fltkui/jgmanager.cpp
+++ b/source/fltkui/jgmanager.cpp
@@ -41,7 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace {
 
-int frametime = 0;
+int frametime{60};
 
 void jg_frametime(double interval) {
     frametime = interval + 0.5;
diff --git a/source/fltkui/videomanager.cpp b/source/fltkui/videomanager.cpp
index 382c1ca..e48c44d 100644
--- a/source/fltkui/videomanager.cpp
+++ b/source/fltkui/videomanager.cpp
@@ -41,8 +41,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace {
 
-jg_videoinfo_t *vidinfo;
-uint32_t *videobuf;
+jg_videoinfo_t *vidinfo{nullptr};
+uint32_t *videobuf{nullptr};
 
 struct osdtext {
     int xpos;