diff --git a/src/mame/drivers/pc9801.cpp b/src/mame/drivers/pc9801.cpp
index e1feb1639b5..196a0af79fe 100644
--- a/src/mame/drivers/pc9801.cpp
+++ b/src/mame/drivers/pc9801.cpp
@@ -1365,7 +1365,11 @@ READ16_MEMBER(pc9801_state::pc9821_grcg_gvram_r)
 {
 	if(m_ex_video_ff[ANALOG_256_MODE])
 	{
-		return space.read_word(0xf00000|(offset*2)|((m_analog256.write_bank)*0x8000),mem_mask);
+		u16 *ext_gvram = (u16 *)m_ext_gvram.target();
+		int bank = offset >> 14;
+		if(bank <= 1)
+			return ext_gvram[((m_analog256.bank[bank])*0x4000) + (offset & 0x3fff)];
+		return 0xffff;
 	}
 
 	return grcg_gvram_r(space,offset,mem_mask);
@@ -1375,7 +1379,10 @@ WRITE16_MEMBER(pc9801_state::pc9821_grcg_gvram_w)
 {
 	if(m_ex_video_ff[ANALOG_256_MODE])
 	{
-		space.write_word(0xf00000|(offset*2)|(m_analog256.write_bank*0x8000),data,mem_mask);
+		u16 *ext_gvram = (u16 *)m_ext_gvram.target();
+		int bank = offset >> 14;
+		if(bank <= 1)
+			COMBINE_DATA(&ext_gvram[((m_analog256.bank[bank])*0x4000) + (offset & 0x3fff)]);
 		return;
 	}
 
@@ -1388,8 +1395,8 @@ READ16_MEMBER(pc9801_state::pc9821_grcg_gvram0_r)
 	{
 		switch(offset*2)
 		{
-			case 4: return m_analog256.write_bank;
-//          case 6: return m_analog256.read_bank;
+			case 4: return m_analog256.bank[0] & 0xf;
+			case 6: return m_analog256.bank[1] & 0xf;
 		}
 
 		//return 0;
@@ -1405,8 +1412,8 @@ WRITE16_MEMBER(pc9801_state::pc9821_grcg_gvram0_w)
 		//printf("%08x %08x\n",offset*2,data);
 		switch(offset*2)
 		{
-			case 4: COMBINE_DATA(&m_analog256.write_bank); break;
-//          case 6: COMBINE_DATA(&m_analog256.read_bank); break;
+			case 4: COMBINE_DATA(&m_analog256.bank[0]); break;
+			case 6: COMBINE_DATA(&m_analog256.bank[1]); break;
 		}
 		//return;
 	}
@@ -1417,12 +1424,12 @@ WRITE16_MEMBER(pc9801_state::pc9821_grcg_gvram0_w)
 
 void pc9801_state::pc9821_map(address_map &map)
 {
-	//AM_RANGE(0x00080000, 0x0009ffff) AM_READWRITE8(winram_r, winram_w, 0xffffffff)
+	//map(0x00080000, 0x0009ffff).rw(this, FUNC(pc9801_state::winram_r), FUNC(pc9801_state::winram_w))
 	map(0x000a0000, 0x000a3fff).rw(this, FUNC(pc9801_state::tvram_r), FUNC(pc9801_state::tvram_w));
 	map(0x000a4000, 0x000a4fff).rw(this, FUNC(pc9801_state::pc9801rs_knjram_r), FUNC(pc9801_state::pc9801rs_knjram_w));
 	map(0x000a8000, 0x000bffff).rw(this, FUNC(pc9801_state::pc9821_grcg_gvram_r), FUNC(pc9801_state::pc9821_grcg_gvram_w));
 	map(0x000cc000, 0x000cdfff).rom().region("sound_bios", 0); //sound BIOS
-//  AM_RANGE(0x000d8000, 0x000d9fff) AM_ROM AM_REGION("ide",0)
+	//map(0x000d8000, 0x000d9fff).rom().region("ide",0)
 	map(0x000da000, 0x000dbfff).ram(); // ide ram
 	map(0x000e0000, 0x000e7fff).rw(this, FUNC(pc9801_state::pc9821_grcg_gvram0_r), FUNC(pc9801_state::pc9821_grcg_gvram0_w));
 	map(0x000e8000, 0x000fffff).m(m_ipl, FUNC(address_map_bank_device::amap16));
diff --git a/src/mame/includes/pc9801.h b/src/mame/includes/pc9801.h
index c2a311d7e94..c55dd1f7f35 100644
--- a/src/mame/includes/pc9801.h
+++ b/src/mame/includes/pc9801.h
@@ -109,6 +109,23 @@ public:
 	{
 	}
 
+	void pc9821v20(machine_config &config);
+	void pc9801ux(machine_config &config);
+	void pc9801vm(machine_config &config);
+	void pc9801(machine_config &config);
+	void pc9801bx2(machine_config &config);
+	void pc9821ap2(machine_config &config);
+	void pc9821(machine_config &config);
+	void pc9801rs(machine_config &config);
+	DECLARE_CUSTOM_INPUT_MEMBER(system_type_r);
+	DECLARE_DRIVER_INIT(pc9801_kanji);
+
+protected:
+	virtual void video_start() override;
+	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
+
+private:
+
 	required_device<cpu_device> m_maincpu;
 	required_device<am9517a_device> m_dmac;
 	required_device<pit8253_device> m_pit8253;
@@ -160,7 +177,6 @@ public:
 	DECLARE_READ8_MEMBER(gvram_r);
 	DECLARE_WRITE8_MEMBER(gvram_w);
 	DECLARE_WRITE8_MEMBER(pc9801rs_mouse_freq_w);
-	DECLARE_CUSTOM_INPUT_MEMBER(system_type_r);
 	DECLARE_READ16_MEMBER(grcg_gvram_r);
 	DECLARE_WRITE16_MEMBER(grcg_gvram_w);
 	DECLARE_READ16_MEMBER(grcg_gvram0_r);
@@ -285,7 +301,6 @@ public:
 	TIMER_DEVICE_CALLBACK_MEMBER( mouse_irq_cb );
 	DECLARE_READ8_MEMBER(unk_r);
 
-	DECLARE_DRIVER_INIT(pc9801_kanji);
 
 	uint32_t screen_update(screen_device &screen, bitmap_rgb32 &bitmap, const rectangle &cliprect);
 	uint32_t a20_286(bool state);
@@ -296,14 +311,6 @@ public:
 	void pc9801_sasi(machine_config &config);
 	void pc9801_ide(machine_config &config);
 	void pc9801_common(machine_config &config);
-	void pc9821v20(machine_config &config);
-	void pc9801ux(machine_config &config);
-	void pc9801vm(machine_config &config);
-	void pc9801(machine_config &config);
-	void pc9801bx2(machine_config &config);
-	void pc9821ap2(machine_config &config);
-	void pc9821(machine_config &config);
-	void pc9801rs(machine_config &config);
 	void ipl_bank(address_map &map);
 	void pc9801_common_io(address_map &map);
 	void pc9801_io(address_map &map);
@@ -317,12 +324,7 @@ public:
 	void upd7220_1_map(address_map &map);
 	void upd7220_2_map(address_map &map);
 	void upd7220_grcg_2_map(address_map &map);
-protected:
-	virtual void video_start() override;
-	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr) override;
 
-
-private:
 	enum
 	{
 		TIMER_VBIRQ
@@ -380,8 +382,7 @@ private:
 	struct {
 		uint8_t pal_entry;
 		uint8_t r[0x100],g[0x100],b[0x100];
-		uint16_t read_bank;
-		uint16_t write_bank;
+		uint16_t bank[2];
 	}m_analog256;
 	struct {
 		uint8_t mode;
diff --git a/src/mame/video/pc9801.cpp b/src/mame/video/pc9801.cpp
index fc8b30e2760..b8b1fba704a 100644
--- a/src/mame/video/pc9801.cpp
+++ b/src/mame/video/pc9801.cpp
@@ -60,7 +60,7 @@ UPD7220_DISPLAY_PIXELS_MEMBER( pc9801_state::hgdc_display_pixels )
 			res_x = x + xi;
 			res_y = y;
 
-			pen = ext_gvram[(address >> 1)*16+xi+(m_vram_disp*0x20000)];
+			pen = ext_gvram[(address >> 1)*16+xi+(m_vram_disp*0x40000)];
 
 			bitmap.pix32(res_y, res_x) = palette[pen + 0x20];
 		}