diff --git a/src/mame/drivers/8080bw.c b/src/mame/drivers/8080bw.c
index 10aca64a9cd..242930824bd 100644
--- a/src/mame/drivers/8080bw.c
+++ b/src/mame/drivers/8080bw.c
@@ -643,28 +643,45 @@ INPUT_PORTS_END
 /*  Preliminary emulation. PCB was working fine, but   */
 /*  it's not certain that this is a good dump          */
 /*                                                     */
+/*  Ports 41 and 48 output 0 at start, not used again  */
+/*  Sounds could be memory-mapped?                     */
+/*  Seems to be no watchdog reset line                 */
+/*  Diplocs need confirming                            */
+/*  Couldn't confirm 2500 for extra life, game too hard*/
+/* Always in cocktail mode but flipscreen bit not found*/
+/*                                                     */
 /*******************************************************/
 
 static INPUT_PORTS_START( spacecom )
 	PORT_START("IN0") // 5-pos dipsw at ic79 (row F) - means 3 bits are for something else, which?
-	PORT_DIPUNKNOWN( 0x01, 0x01 )
-	PORT_DIPUNKNOWN( 0x02, 0x02 )
-	PORT_DIPUNKNOWN( 0x04, 0x04 )
-	PORT_DIPUNKNOWN( 0x08, 0x08 )
-	PORT_DIPUNKNOWN( 0x10, 0x10 )
-	PORT_DIPUNKNOWN( 0x20, 0x20 )
-	PORT_DIPUNKNOWN( 0x40, 0x40 )
-	PORT_DIPUNKNOWN( 0x80, 0x80 )
+	PORT_DIPNAME( 0x01, 0x01, DEF_STR( Unknown ) )	PORT_DIPLOCATION("SW1:1")
+	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
+	PORT_DIPSETTING(    0x01, DEF_STR( Off ) )
+	PORT_DIPNAME( 0x02, 0x02, DEF_STR( Unknown ) )	PORT_DIPLOCATION("SW1:2")
+	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
+	PORT_DIPSETTING(    0x02, DEF_STR( Off ) )
+	PORT_DIPNAME( 0x04, 0x00, DEF_STR( Lives ) )	PORT_DIPLOCATION("SW1:3")
+	PORT_DIPSETTING(    0x00, "3" )
+	PORT_DIPSETTING(    0x04, "5" )
+	PORT_DIPNAME( 0x08, 0x08, DEF_STR( Bonus_Life ) )	PORT_DIPLOCATION("SW1:4")
+	PORT_DIPSETTING(    0x00, "2500" ) // not confirmed
+	PORT_DIPSETTING(    0x08, "1500" )
+	PORT_DIPNAME( 0x10, 0x10, DEF_STR( Unknown ) )	PORT_DIPLOCATION("SW1:5")
+	PORT_DIPSETTING(    0x00, DEF_STR( On ) )
+	PORT_DIPSETTING(    0x10, DEF_STR( Off ) )
+	PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_BUTTON1 ) PORT_PLAYER(2)
+	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_2WAY PORT_PLAYER(2)
+	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_2WAY PORT_PLAYER(2)
 
 	PORT_START("IN1")
 	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_COIN1 )
 	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_START2 )
 	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_START1 )
 	PORT_SERVICE( 0x08, IP_ACTIVE_HIGH )
-	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_BUTTON1 )
-	PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_2WAY
-	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_2WAY
-	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_COIN2 )
+	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_UNKNOWN )
+	PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_BUTTON1 )
+	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT ) PORT_2WAY
+	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT ) PORT_2WAY
 
 	PORT_START(CABINET_PORT_TAG)		/* Dummy port for cocktail mode */
 	PORT_BIT( 0xff, IP_ACTIVE_HIGH, IPT_UNKNOWN )
@@ -675,7 +692,7 @@ static ADDRESS_MAP_START( spacecom_io_map, AS_IO, 8, _8080bw_state )
 	AM_RANGE(0x41, 0x41) AM_READ_PORT("IN0")
 	AM_RANGE(0x42, 0x42) AM_READ_PORT("IN1") AM_DEVWRITE_LEGACY("mb14241", mb14241_shift_count_w)
 	AM_RANGE(0x44, 0x44) AM_DEVREAD_LEGACY("mb14241", mb14241_shift_result_r) AM_DEVWRITE_LEGACY("mb14241", mb14241_shift_data_w)
-	AM_RANGE(0x48, 0x48) AM_WRITE(watchdog_reset_w)
+	//AM_RANGE(0x48, 0x48) AM_WRITE(watchdog_reset_w)
 ADDRESS_MAP_END
 
 MACHINE_CONFIG_DERIVED_CLASS( spacecom, invaders, _8080bw_state )
@@ -683,6 +700,8 @@ MACHINE_CONFIG_DERIVED_CLASS( spacecom, invaders, _8080bw_state )
 	/* basic machine hardware */
 	MCFG_CPU_MODIFY("maincpu")
 	MCFG_CPU_IO_MAP(spacecom_io_map)
+	MCFG_WATCHDOG_VBLANK_INIT(0)
+	MCFG_WATCHDOG_TIME_INIT(attotime::from_usec(0))
 MACHINE_CONFIG_END
 
 
@@ -2922,6 +2941,7 @@ ROM_START( spacecom )
 	ROM_LOAD( "6g.ic84",      0x1400, 0x0400, CRC(de383625) SHA1(7ec0d7171e771c4b43e026f3f50a88d8ab2236bb) )
 	ROM_LOAD( "7f.ic70",      0x1800, 0x0400, CRC(5a23dbc8) SHA1(4d193bb7b38fb7ccd57d2c72463a3fe123dbca58) )
 	ROM_LOAD( "8g.ic85",      0x1c00, 0x0400, CRC(a5a467e3) SHA1(ef591059e55d21f14baa8af1f1324a9bc2ada8c4) )
+	ROM_FILL(0x10, 1, 0xF5) // fix bad byte
 ROM_END
 
 ROM_START( sinvzen )