diff --git a/src/mess/drivers/alesis.c b/src/mess/drivers/alesis.c
index a815df5b768..e0168c8eb80 100644
--- a/src/mess/drivers/alesis.c
+++ b/src/mess/drivers/alesis.c
@@ -235,13 +235,15 @@ void alesis_state::machine_reset()
 static HD44780_INTERFACE( hr16_display )
 {
 	2,					// number of lines
-	16					// chars for line
+	16,					// chars for line
+	NULL				// pixel update callback
 };
 
 static HD44780_INTERFACE( sr16_display )
 {
 	2,					// number of lines
-	8					// chars for line
+	8,					// chars for line
+	NULL				// pixel update callback
 };
 
 static const cassette_interface hr16_cassette_interface =
diff --git a/src/mess/drivers/lcmate2.c b/src/mess/drivers/lcmate2.c
index a2eaf272a92..987f93a1a50 100644
--- a/src/mess/drivers/lcmate2.c
+++ b/src/mess/drivers/lcmate2.c
@@ -205,7 +205,8 @@ void lcmate2_state::machine_start()
 static HD44780_INTERFACE( lcmate2_display )
 {
 	2,					// number of lines
-	20					// chars for line
+	20,					// chars for line
+	NULL				// pixel update callback
 };
 
 static const gfx_layout lcmate2_charlayout =
diff --git a/src/mess/drivers/mmodular.c b/src/mess/drivers/mmodular.c
index 5c9c29d11d2..fb96c661175 100644
--- a/src/mess/drivers/mmodular.c
+++ b/src/mess/drivers/mmodular.c
@@ -191,7 +191,8 @@ public:
 static HD44780_INTERFACE( chess_display )
 {
     2,                  // number of lines
-    16                  // chars for line
+    16,					// chars for line
+	NULL				// pixel update callback
 };
 
 static UINT8 convert_imputmask(UINT8 input)
diff --git a/src/mess/drivers/pc2000.c b/src/mess/drivers/pc2000.c
index 556980acc63..fe96c2d77f3 100644
--- a/src/mess/drivers/pc2000.c
+++ b/src/mess/drivers/pc2000.c
@@ -319,7 +319,8 @@ GFXDECODE_END
 static HD44780_INTERFACE( pc2000_display )
 {
 	2,					// number of lines
-	20					// chars for line
+	20,					// chars for line
+	NULL				// pixel update callback
 };
 
 static MACHINE_CONFIG_START( pc2000, pc2000_state )
diff --git a/src/mess/drivers/psion.c b/src/mess/drivers/psion.c
index f070e9a2d47..2fdbedb86f2 100644
--- a/src/mess/drivers/psion.c
+++ b/src/mess/drivers/psion.c
@@ -463,7 +463,8 @@ GFXDECODE_END
 static HD44780_INTERFACE( psion_2line_display )
 {
 	2,					// number of lines
-	16					// chars for line
+	16,					// chars for line
+	NULL				// pixel update callback
 };
 
 /* basic configuration for 2 lines display */
@@ -506,7 +507,8 @@ MACHINE_CONFIG_END
 static HD44780_INTERFACE( psion_4line_display )
 {
 	4,					// number of lines
-	20					// chars for line
+	20,					// chars for line
+	NULL				// pixel update callback
 };
 
 /* basic configuration for 4 lines display */
diff --git a/src/mess/video/hd44780.c b/src/mess/video/hd44780.c
index 8050c68a007..c89e00855e6 100644
--- a/src/mess/video/hd44780.c
+++ b/src/mess/video/hd44780.c
@@ -37,6 +37,7 @@ void hd44780_device::device_config_complete()
 	else
 	{
 		height = width = 0;
+		pixel_update_func = NULL;
 	}
 }
 
@@ -141,7 +142,14 @@ void hd44780_device::set_busy_flag(UINT16 usec)
 	m_busy_flag = 1;
 
 	m_busy_timer->adjust( attotime::from_usec( usec ) );
+}
 
+inline void hd44780_device::pixel_update(bitmap_ind16 &bitmap, UINT8 line, UINT8 pos, UINT8 y, UINT8 x, int state)
+{
+	if (pixel_update_func != NULL)
+		pixel_update_func(*this, bitmap, line, pos, y, x, state);
+	else
+		bitmap.pix16(line*9 + y, pos*6 + x) = state;
 }
 
 //**************************************************************************
@@ -177,21 +185,21 @@ UINT32 hd44780_device::screen_update(screen_device &screen, bitmap_ind16 &bitmap
 						if (m_ddram[char_pos] <= 0x10)
 						{
 							//draw CGRAM characters
-							bitmap.pix16(l*9 + y, i*6 + x) = BIT(m_cgram[(m_ddram[char_pos]&0x07)*8+y], 4-x);
+							pixel_update(bitmap, l, i, y, x, BIT(m_cgram[(m_ddram[char_pos]&0x07)*8+y], 4-x));
 						}
 						else
 						{
 							//draw CGROM characters
 							if (region()->bytes() <= 0x800)
 							{
-								bitmap.pix16(l*9 + y, i*6 + x) = BIT(region()->u8(m_ddram[char_pos]*8+y), 4-x);
+								pixel_update(bitmap, l, i, y, x, BIT(region()->u8(m_ddram[char_pos]*8+y), 4-x));
 							}
 							else
 							{
 								if(m_ddram[char_pos] < 0xe0)
-									bitmap.pix16(l*9 + y, i*6 + x) = BIT(region()->u8(m_ddram[char_pos]*8+y), 4-x);
+									pixel_update(bitmap, l, i, y, x, BIT(region()->u8(m_ddram[char_pos]*8+y), 4-x));
 								else
-									bitmap.pix16(l*9 + y, i*6 + x) = BIT(region()->u8(0x700+((m_ddram[char_pos]-0xe0)*11)+y), 4-x);
+									pixel_update(bitmap, l, i, y, x, BIT(region()->u8(0x700+((m_ddram[char_pos]-0xe0)*11)+y), 4-x));
 							}
 						}
 
@@ -201,12 +209,12 @@ UINT32 hd44780_device::screen_update(screen_device &screen, bitmap_ind16 &bitmap
 					//draw the cursor
 					if (m_cursor_on)
 						for (int x=0; x<5; x++)
-							bitmap.pix16(l*9 + 7, i * 6 + x) = 1;
+							pixel_update(bitmap, l, i, 7, x, 1);
 
 					if (!m_blink && m_blink_on)
 						for (int y=0; y<7; y++)
 							for (int x=0; x<5; x++)
-								bitmap.pix16(l*9 + y, i * 6 + x) = 1;
+								pixel_update(bitmap, l, i, y, x, 1);
 				}
 			}
 
diff --git a/src/mess/video/hd44780.h b/src/mess/video/hd44780.h
index 483f30c2ea0..94584c34323 100644
--- a/src/mess/video/hd44780.h
+++ b/src/mess/video/hd44780.h
@@ -21,12 +21,16 @@
 #define HD44780_INTERFACE(name) \
 	const hd44780_interface (name) =
 
+typedef void (*hd44780_pixel_update_func)(device_t &device, bitmap_ind16 &bitmap, UINT8 line, UINT8 pos, UINT8 y, UINT8 x, int state);
+#define HD44780_PIXEL_UPDATE(name) void name(device_t &device, bitmap_ind16 &bitmap, UINT8 line, UINT8 pos, UINT8 y, UINT8 x, int state)
+
 // ======================> hd44780_interface
 
 struct hd44780_interface
 {
 	UINT8 height;			// number of lines
 	UINT8 width;			// chars for line
+	hd44780_pixel_update_func pixel_update_func;	// pixel update callback
 };
 
 // ======================> hd44780_device
@@ -59,6 +63,7 @@ protected:
 	// internal helper
 	void set_busy_flag(UINT16 usec);
 	void update_ac(void);
+	void pixel_update(bitmap_ind16 &bitmap, UINT8 line, UINT8 pos, UINT8 y, UINT8 x, int state);
 	// internal state
 	static const device_timer_id BUSY_TIMER = 0;
 	static const device_timer_id BLINKING_TIMER = 1;