diff --git a/src/mame/drivers/gkigt.cpp b/src/mame/drivers/gkigt.cpp
index 1f0c9725dff..5bf12d9707c 100644
--- a/src/mame/drivers/gkigt.cpp
+++ b/src/mame/drivers/gkigt.cpp
@@ -237,10 +237,10 @@ static ADDRESS_MAP_START( igt_gameking_map, AS_PROGRAM, 32, igt_gameking_state )
 	AM_RANGE(0x2801001c, 0x2801001f) AM_WRITENOP
 	AM_RANGE(0x28010030, 0x28010033) AM_READ(uart_status_r) // channel D
 	AM_RANGE(0x28010034, 0x28010037) AM_WRITE(uart_w)       // channel D
-	// 28020000-2802007f: second 28C94 QUART
+	AM_RANGE(0x28020000, 0x280205ff) AM_RAM // CMOS?
 //	AM_RANGE(0x28020000, 0x2802007f) AM_READ(igt_gk_28010008_r) AM_WRITENOP
 	AM_RANGE(0x28030000, 0x28030003) AM_READ_PORT("IN0")
-//	AM_RANGE(0x28040000, 0x2804ffff) AM_RAM
+	// 28040000-2804007f: second 28C94 QUART
 	AM_RANGE(0x28040008, 0x2804000b) AM_WRITE8(unk_w,0x00ff0000)
 	AM_RANGE(0x28040008, 0x2804000b) AM_READWRITE8(irq_vector_r,irq_enable_w,0x000000ff)
 	AM_RANGE(0x28040018, 0x2804001b) AM_READ_PORT("IN1") AM_WRITENOP