diff --git a/Makefile b/Makefile
index 3ac1c01..2bb0999 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 t ?= esp32
 
 TERMINAL_SPEED := 115200
-CPPFLAGS = -DDEBUGGING -DCPU_DEBUG=false -DTERMINAL_SPEED=$(TERMINAL_SPEED) -DUSE_OWN_KBD
+CPPFLAGS = -Wall -DDEBUGGING -DCPU_DEBUG=false -DTERMINAL_SPEED=$(TERMINAL_SPEED) -DUSE_OWN_KBD
 LIBRARIES = PS2KeyAdvanced PS2KeyMap
 
 ifeq ($t, esp8266)
@@ -43,7 +43,9 @@ endif
 ifeq ($t, rp2040)
 BOARD := adafruit_feather_dvi
 FLASH := 8388608_2097152
-CPPFLAGS += -DHARDWARE_H=\"hw/adafruit_feather_dvi.h\" -DPS2_SERIAL_KBD=\"UK\"
+CPPFLAGS += -DHARDWARE_H=\"hw/adafruit_feather_dvi.h\" -DUSE_SERIAL
+#CPPFLAGS += -DHARDWARE_H=\"hw/adafruit_feather_dvi.h\" -DPS2_SERIAL_KBD=\"UK\"
+CPPFLAGS += -DDVI_BIT_DEPTH=1 -DDVI_RESOLUTION=DVI_RES_640x240p60
 LIBRARIES += LittleFS PicoDVI Adafruit_GFX Adafruit_BusIO Wire
 endif
 
diff --git a/screen_disp.cpp b/screen_disp.cpp
index aff16a0..1dc9d0d 100644
--- a/screen_disp.cpp
+++ b/screen_disp.cpp
@@ -16,7 +16,7 @@ const int TICK_FREQ = 2;
 void IRAM_ATTR screen_disp::on_tick() {
 
 	static int tick = 0;
-	tick = ++tick % 3;
+	tick = (tick + 1) % 3;
 	i->cursor(tick < 2);
 }
 
@@ -28,8 +28,8 @@ void screen_disp::reset() {
 	}
 
 	Display::begin(BG_COLOUR, FG_COLOUR, ORIENT);
+	Display::setScreen(COLS * charWidth(), ROWS * charHeight());
 	Display::clear();
-	_cy += 2;
 
 	r = c = 0;
 	for (int j = 0; j < ROWS; j++)
@@ -45,7 +45,7 @@ void screen_disp::draw(char ch, int i, int j) {
 	if (screen[j][i] != ch) {
 		screen[j][i] = ch;
 		char c[2] = { ch, 0 };
-		drawString(c, i*_cx, j*_cy);
+		drawString(c, i * charWidth(), j * charHeight());
 	}
 }