diff --git a/src/mame/includes/osborne1.h b/src/mame/includes/osborne1.h
index 2e041703d94..be11edb2927 100644
--- a/src/mame/includes/osborne1.h
+++ b/src/mame/includes/osborne1.h
@@ -30,6 +30,7 @@ public:
 	osborne1_state(const machine_config &mconfig, device_type type, const char *tag) :
 		driver_device(mconfig, type, tag),
 		m_maincpu(*this, "maincpu"),
+		m_gfxdecode(*this, "gfxdecode"),
 		m_speaker(*this, "speaker"),
 		m_pia0(*this, "pia_0"),
 		m_pia1(*this, "pia_1"),
@@ -54,6 +55,8 @@ public:
 		m_bank_1xxx(*this, "bank_1xxx"),
 		m_bank_fxxx(*this, "bank_fxxx"),
 		m_video_timer(NULL),
+		m_p_chargen(NULL),
+		m_tilemap(NULL),
 		m_acia_rxc_txc_timer(NULL)
 	{ }
 
@@ -84,6 +87,7 @@ public:
 	UINT32 screen_update(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect);
 
 	required_device<cpu_device>             m_maincpu;
+	required_device<gfxdecode_device>       m_gfxdecode;
 	required_device<speaker_sound_device>   m_speaker;
 	required_device<pia6821_device>         m_pia0;
 	required_device<pia6821_device>         m_pia1;
@@ -98,6 +102,8 @@ protected:
 	virtual void device_timer(emu_timer &timer, device_timer_id id, int param, void *ptr);
 	TIMER_CALLBACK_MEMBER(video_callback);
 
+	TILE_GET_INFO_MEMBER(get_tile_info);
+
 	bool set_rom_mode(UINT8 value);
 	bool set_bit_9(UINT8 value);
 	void update_irq();
@@ -142,6 +148,7 @@ protected:
 	emu_timer       *m_video_timer;
 	bitmap_ind16    m_bitmap;
 	UINT8           *m_p_chargen;
+	tilemap_t       *m_tilemap;
 
 	// SCREEN-PAC registers
 	UINT8           m_resolution;
diff --git a/src/mame/machine/osborne1.c b/src/mame/machine/osborne1.c
index 7e0e53d213a..1bfe32da7dd 100644
--- a/src/mame/machine/osborne1.c
+++ b/src/mame/machine/osborne1.c
@@ -96,7 +96,10 @@ WRITE8_MEMBER( osborne1_state::bank_2xxx_3xxx_w )
 WRITE8_MEMBER( osborne1_state::videoram_w )
 {
 	// Attribute RAM is only one bit wide - low seven bits are discarded and read back high
-	if (m_bit_9) data |= 0x7F;
+	if (m_bit_9)
+		data |= 0x7F;
+	else
+		m_tilemap->mark_tile_dirty(offset);
 	reinterpret_cast<UINT8 *>(m_bank_fxxx->base())[offset] = data;
 }
 
@@ -255,6 +258,10 @@ DRIVER_INIT_MEMBER( osborne1_state, osborne1 )
 
 	m_p_chargen = memregion("chargen")->base();
 	m_video_timer = timer_alloc(TIMER_VIDEO);
+	m_tilemap = &machine().tilemap().create(
+			m_gfxdecode,
+			tilemap_get_info_delegate(FUNC(osborne1_state::get_tile_info), this), TILEMAP_SCAN_ROWS,
+			8, 10, 128, 32);
 
 	m_acia_rxc_txc_timer = timer_alloc(TIMER_ACIA_RXC_TXC);
 
@@ -437,6 +444,13 @@ TIMER_CALLBACK_MEMBER(osborne1_state::video_callback)
 }
 
 
+TILE_GET_INFO_MEMBER(osborne1_state::get_tile_info)
+{
+	// The gfxdecode and tilemap aren't actually used for drawing, they just look nice in the F4 GFX viewer
+	tileinfo.set(0, m_ram->pointer()[0xF000 | tile_index] & 0x7F, 0, 0);
+}
+
+
 bool osborne1_state::set_rom_mode(UINT8 value)
 {
 	if (value != m_rom_mode)