diff --git a/src/devices/bus/isa/3c505.cpp b/src/devices/bus/isa/3c505.cpp
index aa9d0dfbb54..6dd695165c2 100644
--- a/src/devices/bus/isa/3c505.cpp
+++ b/src/devices/bus/isa/3c505.cpp
@@ -157,10 +157,10 @@ static INPUT_PORTS_START(3c505)
 
 	PORT_DIPNAME(0xfe, 0x00, "ROM Base")
 	// Apollo host ROM addresses
-	PORT_DIPSETTING(   0x00, "00000h")
-	PORT_DIPSETTING(   0x02, "02000h")
-	PORT_DIPSETTING(   0x04, "04000h")
-	PORT_DIPSETTING(   0x06, "06000h")
+	PORT_DIPSETTING(   0x00, "80000h")
+	PORT_DIPSETTING(   0x02, "82000h")
+	PORT_DIPSETTING(   0x04, "84000h")
+	PORT_DIPSETTING(   0x06, "86000h")
 
 	// conventional PC option ROM addresses
 	PORT_DIPSETTING(   0xc8, "C8000h")