diff --git a/src/mame/olivetti/att6300p.cpp b/src/mame/olivetti/att6300p.cpp
index 736bb75915d27..8e0586906071e 100644
--- a/src/mame/olivetti/att6300p.cpp
+++ b/src/mame/olivetti/att6300p.cpp
@@ -856,47 +856,49 @@ void att6300p_state::att6300p_vio_map(address_map &map)
 	map(0x3fe0, 0x3fe0).mirror(0x001f).rw(FUNC(att6300p_state::cltrap_r), FUNC(att6300p_state::cltrap_w));
 }
 
+// Off switches read as 1, On switches as 0.
 static INPUT_PORTS_START( att6300p )
 	PORT_START("DSW1")
 
-	PORT_DIPNAME( 0x01, 0x00, "Drive B Type")
-	PORT_DIPSETTING(    0x00, "96 TPI" )
-	PORT_DIPSETTING(    0x01, "48 TPI" )
-	PORT_DIPNAME( 0x02, 0x00, "Drive A Type")
-	PORT_DIPSETTING(    0x00, "96 TPI" )
-	PORT_DIPSETTING(    0x02, "48 TPI" )
-	PORT_DIPNAME( 0x0c, 0x00, "Hard Disk Type")
+	PORT_DIPNAME( 0x01, 0x01, "Drive B Type")			PORT_DIPLOCATION("DSW1:1")
+	PORT_DIPSETTING(    0x01, "96 TPI" )
+	PORT_DIPSETTING(    0x00, "48 TPI" )
+	PORT_DIPNAME( 0x02, 0x02, "Drive A Type")			PORT_DIPLOCATION("DSW1:2")
+	PORT_DIPSETTING(    0x02, "96 TPI" )
+	PORT_DIPSETTING(    0x00, "48 TPI" )
+	PORT_DIPNAME( 0x04, 0x04, "Hard Disk 1 Type")		PORT_DIPLOCATION("DSW1:3")
 	PORT_DIPSETTING(    0x00, "0" )
-	PORT_DIPSETTING(    0x40, "1" )
-	PORT_DIPSETTING(    0x80, "2" )
-	PORT_DIPSETTING(    0xc0, "3" )
-	PORT_DIPNAME( 0x30, 0x10, "Display Type")
-	PORT_DIPSETTING(    0x00, "Monochrome" )
-	PORT_DIPSETTING(    0x10, "Color 80x25" )
-	PORT_DIPSETTING(    0x20, "Color 40x25" )
-	PORT_DIPNAME( 0xc0, 0x80, "Number of floppy drives")
-	PORT_DIPSETTING(    0xc0, "1" )
-	PORT_DIPSETTING(    0x80, "2" )
-	PORT_DIPSETTING(    0x40, "3" )
+	PORT_DIPSETTING(    0x04, "1" )
+	PORT_DIPNAME( 0x08, 0x08, "Hard Disk 0 Type")		PORT_DIPLOCATION("DSW1:4")
+	PORT_DIPSETTING(    0x00, "0" )
+	PORT_DIPSETTING(    0x08, "1" )
+	PORT_DIPNAME( 0x30, 0x20, "Display Type")			PORT_DIPLOCATION("DSW1:5,6")
+	PORT_DIPSETTING(    0x10, "Color 40x25" )
+	PORT_DIPSETTING(    0x20, "Color 80x25" )
+	PORT_DIPSETTING(    0x30, "Monochrome" )
+	PORT_DIPNAME( 0xc0, 0x40, "Number of floppy drives")	PORT_DIPLOCATION("DSW1:7,8")
+	PORT_DIPSETTING(    0x00, "1" )
+	PORT_DIPSETTING(    0x40, "2" )
+	PORT_DIPSETTING(    0x80, "3" )
 
 	PORT_START("DSW2")
 
-	PORT_DIPNAME( 0x0f, 0x0b, "Motherboard RAM banks")
+	PORT_DIPNAME( 0x0f, 0x0b, "Motherboard RAM banks")	PORT_DIPLOCATION("DSW2:1,2,3,4")
 	PORT_DIPSETTING(    0x01, "128K - 128/0")
 	PORT_DIPSETTING(    0x02, "256K - 128/128")
 	PORT_DIPSETTING(    0x08, "512K - 512/0")
 	PORT_DIPSETTING(    0x09, "640K - 128/512")
 	PORT_DIPSETTING(    0x0a, "640K - 512/128")
 	PORT_DIPSETTING(    0x0b, "1M - 512/512")
-	PORT_DIPNAME( 0x10, 0x00, "80287 installed")
-	PORT_DIPSETTING(    0x00, DEF_STR(No) )
-	PORT_DIPSETTING(    0x10, DEF_STR(Yes) )
-	PORT_DIPNAME( 0x40, 0x40, "HDD ROM")
-	PORT_DIPSETTING(    0x00, "External" )
-	PORT_DIPSETTING(    0x40, "Internal" )
-	PORT_DIPNAME( 0x80, 0x00, "EPROM Size")
-	PORT_DIPSETTING(    0x00, "32K" )
-	PORT_DIPSETTING(    0x80, "64K" )
+	PORT_DIPNAME( 0x10, 0x10, "80287 installed")		PORT_DIPLOCATION("DSW2:5")
+	PORT_DIPSETTING(    0x00, DEF_STR(Yes) )
+	PORT_DIPSETTING(    0x10, DEF_STR(No) )
+	PORT_DIPNAME( 0x40, 0x40, "HDD ROM")		        PORT_DIPLOCATION("DSW2:7")
+	PORT_DIPSETTING(    0x00, "Internal" )
+	PORT_DIPSETTING(    0x40, "External" )
+	PORT_DIPNAME( 0x80, 0x80, "EPROM Size")		        PORT_DIPLOCATION("DSW2:8")
+	PORT_DIPSETTING(    0x00, "64K" )
+	PORT_DIPSETTING(    0x80, "32K" )
 INPUT_PORTS_END
 
 void att6300p_state::floppy_formats(format_registration &fr)