diff --git a/src/mame/drivers/f1gp.cpp b/src/mame/drivers/f1gp.cpp
index 0dd158e7ec8..f62dd0e13a3 100644
--- a/src/mame/drivers/f1gp.cpp
+++ b/src/mame/drivers/f1gp.cpp
@@ -201,8 +201,9 @@ static INPUT_PORTS_START( f1gp )
 	PORT_BIT( 0x0002, IP_ACTIVE_LOW, IPT_UNUSED ) PORT_CONDITION("JOY_TYPE", 0x01, EQUALS, 0x01)
 	PORT_BIT( 0x0004, IP_ACTIVE_LOW, IPT_JOYSTICK_LEFT ) PORT_2WAY PORT_CONDITION("JOY_TYPE", 0x01, EQUALS, 0x01)
 	PORT_BIT( 0x0008, IP_ACTIVE_LOW, IPT_JOYSTICK_RIGHT ) PORT_2WAY PORT_CONDITION("JOY_TYPE", 0x01, EQUALS, 0x01)
-	PORT_BIT( 0x0010, IP_ACTIVE_LOW, IPT_BUTTON1 ) PORT_NAME("P1 Brake Button")
-	PORT_BIT( 0x0020, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_NAME("P1 Accelerator Button")
+	// following two are logically arranged as per service mode
+	PORT_BIT( 0x0010, IP_ACTIVE_LOW, IPT_BUTTON2 ) PORT_NAME("P1 Brake Button")
+	PORT_BIT( 0x0020, IP_ACTIVE_LOW, IPT_BUTTON1 ) PORT_NAME("P1 Accelerator Button")
 	PORT_BIT( 0x0040, IP_ACTIVE_LOW, IPT_UNKNOWN )
 	PORT_BIT( 0x0080, IP_ACTIVE_LOW, IPT_UNKNOWN )
 	PORT_BIT( 0x0100, IP_ACTIVE_LOW, IPT_COIN1 )
@@ -300,11 +301,11 @@ static INPUT_PORTS_START( f1gp )
 INPUT_PORTS_END
 
 
-/* the same as f1gp, but with an extra button */
 static INPUT_PORTS_START( f1gp2 )
 	PORT_INCLUDE( f1gp )
 
 	PORT_MODIFY("INPUTS")
+	// additional button, complies with 1992 F1 season
 	PORT_BIT( 0x0040, IP_ACTIVE_LOW, IPT_BUTTON3 ) PORT_NAME("P1 Turbo Button")
 
 	PORT_MODIFY("DSW3")