diff --git a/src/mame/drivers/notechan.cpp b/src/mame/drivers/notechan.cpp
index d7c37fcecad..b702d1b8dd3 100644
--- a/src/mame/drivers/notechan.cpp
+++ b/src/mame/drivers/notechan.cpp
@@ -315,15 +315,18 @@ static INPUT_PORTS_START( notechan )
Port FAh:
- (1) Pulsed under reset, activates lamp 21 and triggers sample #20 (boing). Maybe it's
- the 'start' button.
+ (1) Pulsed under reset, activates port FAh-D5 (lamp 21) and triggers sample #20 (boing
+ or FX sound, depending of the OKI bank). Maybe it's the 'start' button.
(2) Pulsing and keep pressed under reset, triggers the sample #01 (cling) and starts
- a sequence of lamps (24-25-26). Then triggers sample #04 (voice). After a little
- while also triggers sample #05 (voice).
+ a sequence of 4-lines output through port FFh D3-D2-D1-D0 (lamps 27-26-25-24)
+ that seems a 4-bits countdown (maybe related to the 7segment LED that counts the
+ credits). Then triggers sample #04 (voice or effect depending of the OKI bank).
+ After a little while also triggers sample #05 (voice).
+ Maybe it's some kind of hardware testing mode...
- (3) Pulsing this input lites lamp 17 and triggers sample #01 (cling). Maybe it's
- the 'coin-in' button.
+ (3) Pulsing this input activates port FAh-D1 (lamp 17) and triggers sample #01 (cling).
+ Maybe it's the 'coin-in' button.
*/
PORT_START("DSW")
diff --git a/src/mame/layout/notechan.lay b/src/mame/layout/notechan.lay
index d3cc330975f..811badcf7dc 100644
--- a/src/mame/layout/notechan.lay
+++ b/src/mame/layout/notechan.lay
@@ -4,6 +4,9 @@
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