diff --git a/src/mame/drivers/spc1500.cpp b/src/mame/drivers/spc1500.cpp
index 5f3cd2a7b18..ac990ff514d 100644
--- a/src/mame/drivers/spc1500.cpp
+++ b/src/mame/drivers/spc1500.cpp
@@ -284,6 +284,7 @@ private:
 	UINT8 *m_p_ram;
 	UINT8 m_ipl;
 	UINT8 m_palet[3];
+	UINT8 m_paltbl[8];
 	UINT16 m_page;
 	UINT16 m_pcg_addr;
 	UINT8 m_pcg_char, m_pcg_attr;
@@ -367,6 +368,8 @@ WRITE8_MEMBER( spc1500_state::portc_w)
 	m_centronics->write_strobe(BIT(data, 7));
 	m_double_mode = (!m_p5bit && BIT(data, 5)); // double access I/O mode
 	m_p5bit = BIT(data, 5);
+	m_vdg->set_clock(VDP_CLOCK/(BIT(data, 2) ? 48 : 24));
+
 }
 
 READ8_MEMBER( spc1500_state::portb_r)
@@ -453,7 +456,8 @@ WRITE8_MEMBER( spc1500_state::priority_w)
 WRITE8_MEMBER( spc1500_state::palet_w)
 {
 	m_palet[(offset>>8)&0x0f] = data;
-//	printf("palet:0x%02x, 0x%02x, 0x%02x\n", m_palet[0], m_palet[1], m_palet[2]);
+	for(int i=1, j=0; i < 0x100; i<<=1, j++)
+		m_paltbl[j] = (m_palet[0]&i?1:0)|(m_palet[1]&i?2:0)|(m_palet[2]&i?4:0);
 }
 
 PALETTE_INIT_MEMBER(spc1500_state,spc)
@@ -495,23 +499,22 @@ MC6845_UPDATE_ROW(spc1500_state::crtc_update_row)
 	char hs = (m_crtc_vreg[0x9] < 15 ? 3 : 4);
 	int n = y & (m_crtc_vreg[0x9]);
 	bool ln400 = (hs == 4 && m_crtc_vreg[0x4] > 20);
+	UINT8 *vram = &m_p_videoram[0] + (m_crtc_vreg[12] << 8) + m_crtc_vreg[13];
 	for (i = 0; i < x_count; i++)
 	{
-		UINT8 *pp = &m_p_videoram[0x2000+((y>>hs)*x_count+(((y)&7)<<11))+i+(((hs==4)&&(y&8))?0x400:0)];
-		UINT8 *pv = &m_p_videoram[(y>>hs)*x_count + i];
+		UINT8 *pp = &vram[0x2000+((y>>hs)*x_count+(((y)&7)<<11))+i+(((hs==4)&&(y&8))?0x400:0)];
+		UINT8 *pv = &vram[(y>>hs)*x_count + i];
 		UINT8 ascii = *(pv+0x1000);
 		UINT8 attr = *pv;
 		inv = (attr & 0x8 ? true : false);
-		UINT8 rgb = (attr & 0x7);
-		UINT8 pal = 1<<rgb;
+		UINT8 color = attr & 0x7;
 		UINT8 pixelb = *(pp+0);
 		UINT8 pixelr = *(pp+0x4000);
 		UINT8 pixelg = *(pp+0x8000);
-		UINT8 pen = (((m_palet[0]&pal)>0)<<2)|(((m_palet[1]&pal)>0)<<1)|(((m_palet[2]&pal)>0));
-		if ((m_palet[0] | m_palet[1] | m_palet[2])==0 || ln400)
-			pen = rgb;
-		UINT32 color = m_palette->pen(pen);
+		bool nopalet = ((m_palet[0] | m_palet[1] | m_palet[2])==0 || ln400);
+		UINT8 pen = (nopalet ? color : m_paltbl[color]);
 		UINT8 pixelpen = 0;
+		UINT8 pixel = 0;
 		if (hs == 4 && ascii & 0x80)
 		{
 			UINT16 wpixelb = (pixelb << 8) + (*(pp+1));
@@ -529,10 +532,11 @@ MC6845_UPDATE_ROW(spc1500_state::crtc_update_row)
 			hfnt = hfnt & ((*pf << 8) | (*(pf+16)));
 			hfnt = (inv ? 0xffff - hfnt : hfnt);
 			//printf("0x%04x\n" , hfnt);
-			for (j = 0; j < 16; j++)
+			for (j = 0x8000; j > 0; j>>=1)
 			{
-				pixelpen = (((wpixelg&(0x8000 >> j))>0 ? 4:0 )|((wpixelr&(0x8000 >> j))>0 ? 2:0)|((wpixelb&(0x8000 >> j))>0 ? 1:0));
-				*p++ = (((hfnt & (0x8000 >> j)) || (m_priority & (1<<pixelpen))) ? m_palette->pen(pixelpen) : color);
+				pixel = ((wpixelg&j ? 4:0 )|(wpixelr&j? 2:0)|(wpixelb&j ? 1:0));
+				pixelpen = (nopalet ? pixel : m_paltbl[pixel]);
+				*p++ = m_palette->pen(((hfnt & j) || (m_priority & (1<<pixel))) ? pixelpen : pen);
 			}
 			i++;
 		}
@@ -542,11 +546,13 @@ MC6845_UPDATE_ROW(spc1500_state::crtc_update_row)
 			UINT8 b = *pa;
 			UINT8 r = *(pa+0x800);
 			UINT8 g = *(pa+0x1000);
-			for (j = 0; j < 8; j++)
+			for (j = 0x80; j > 0; j>>=1)
 			{
-				pen = ((g & (0x80 >> j))>0?4:0)|((r & (0x80>>j))>0?2:0)|((b & (0x80>>j))>0?1:0);
-				pixelpen = (((pixelg&(0x80 >> j))>0 ? 4 : 0)|((pixelr&(0x80 >> j))>0 ? 2:0)|(((pixelb&(0x80 >> j) ? 1:0 ))));
-				*p++ = ((pen == 0 || (m_priority & (1<<pixelpen))) ? m_palette->pen(pixelpen) : m_palette->pen(pen));
+				pixel = ((g & j)?4:0)|((r & j)?2:0)|((b & j)?1:0);
+				pen = (pixel == 7 ? color : pixel);
+				pixel = (pixelg&j ? 4 : 0)|(pixelr&j ? 2:0)|(pixelb&j ? 1:0 );
+				pixelpen = (nopalet ? pixel : m_paltbl[pixel]);
+				*p++ = m_palette->pen((m_priority & (1<<pixel)) ? pixelpen : pen);
 			}
 		}
 		else
@@ -556,16 +562,16 @@ MC6845_UPDATE_ROW(spc1500_state::crtc_update_row)
 			if (ascii == 0 && (attr & 0x08) && inv)
 			{
 				fnt = 0xff;
-				color = m_palette->pen(7);
 			}
 			fnt = (inv ? 0xff - fnt : fnt);
-			for (j = 0; j < 8; j++)
+			for (j = 0x80; j > 0; j>>=1)
 			{
-				pixelpen = (((pixelg&(0x80 >> j))>0 ? 4 : 0)|((pixelr&(0x80 >> j))>0 ? 2:0)|(((pixelb&(0x80 >> j) ? 1:0 ))));
+				pixel = ((pixelg&j) ? 4 : 0)|(pixelr&j ? 2:0)|(pixelb&j ? 1:0 );
+				pixelpen = (nopalet ? pixel : m_paltbl[pixel]);
 				if (ascii == 0 && attr == 0 && !inv)
 					*p++ = m_palette->pen(pixelpen);
 				else
-					*p++ = (((fnt & (0x80 >> j)) || (m_priority & (1<<pixelpen))) ? m_palette->pen(pixelpen) : color);
+					*p++ = m_palette->pen(((fnt & j) || (m_priority & (1<<pixel))) ? pixelpen : pen);
 			}
 		}
 	}
@@ -782,12 +788,14 @@ static INPUT_PORTS_START( spc1500 )
 	PORT_BIT(0x80, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("9 (") PORT_CODE(KEYCODE_9) PORT_CHAR('9') PORT_CHAR('(')
 
 	PORT_START("JOY")
-	PORT_BIT(0x01, IP_ACTIVE_HIGH, IPT_JOYSTICK_UP ) PORT_8WAY PORT_PLAYER(1)
-	PORT_BIT(0x02, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN ) PORT_8WAY PORT_PLAYER(1)
-	PORT_BIT(0x04, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_8WAY PORT_PLAYER(1)
-	PORT_BIT(0x08, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_8WAY PORT_PLAYER(1)
-	PORT_BIT(0x20, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(1)
-	PORT_BIT(0x50, IP_ACTIVE_HIGH, IPT_BUTTON2 ) PORT_PLAYER(1)
+	PORT_BIT(0x01, IP_ACTIVE_LOW, IPT_JOYSTICK_UP ) PORT_8WAY PORT_PLAYER(1)
+	PORT_BIT(0x02, IP_ACTIVE_LOW, IPT_JOYSTICK_DOWN ) PORT_8WAY PORT_PLAYER(1)
+	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT ) PORT_8WAY PORT_PLAYER(1)
+	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_8WAY PORT_PLAYER(1)
+	PORT_BIT(0x10, IP_ACTIVE_HIGH,IPT_UNUSED) // DIP SW2 for Korean/English
+	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_BUTTON1 ) PORT_PLAYER(1)
+	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_PLAYER(1)
+	PORT_BIT(0x80, IP_ACTIVE_HIGH,IPT_UNUSED) // DIP SW3 for 200/400 line 
 INPUT_PORTS_END
 
 static ADDRESS_MAP_START(spc1500_mem, AS_PROGRAM, 8, spc1500_state )
@@ -820,6 +828,7 @@ void spc1500_state::machine_reset()
 	m_motor = false;
    	m_time = machine().scheduler().time();	
 	m_double_mode = false;
+	memset(&m_paltbl[0], 1, 8);
 }
 
 READ8_MEMBER(spc1500_state::mc6845_videoram_r)
@@ -831,6 +840,7 @@ READ8_MEMBER( spc1500_state::psga_r )
 {
 	UINT8 data = 0;
 	data |= (BIT(m_dipsw->read(),1)<<4) | (BIT(m_dipsw->read(),2)<<7);
+	data |= (m_io_joy->read() & 0x6f);
 	return data;
 }
 
@@ -839,7 +849,6 @@ READ8_MEMBER( spc1500_state::porta_r )
 	UINT8 data = 0x3f;
 	data |= (m_cass->input() > 0.0038) ? 0x80 : 0;
 	data |= ((m_cass->get_state() & CASSETTE_MASK_UISTATE) != CASSETTE_STOPPED) && ((m_cass->get_state() & CASSETTE_MASK_MOTOR) == CASSETTE_MOTOR_ENABLED)  ? 0x00 : 0x40;
-	data |= (m_io_joy->read() & 0x6f);
 	data &= ~((m_centronics_busy == 0)<< 5);
 	return data;
 }