Yamaha CS1D Owner's Manual page 467

Input functions
[Screen functions]
In the IN/INS screen, the state of the parameters will be
displayed according to the type of unit or card that is
assigned to that channel.
For an AD card with head amp (LMY2-ML)
1 2
3
For an AD card without head amp (LMY4-AD)
3
For a digital I/O card (MY card)
3
For a 2TR IN is assigned
3
132
For an effect return, graphic EQ output, or talkback
signal is assigned
4
5
6
7
8
9
6
8
9
6
For a channel to which nothing is assigned
0
A
8
9
6
1 GAIN GANG
A
8
9
This button links the head amp gain setting between
adjacent input channels in the screen. (The offset
value will be preserved.) When this button is on,
rotating the GAIN knob (7) of one channel will
cause the knob of the other channel to follow, while
preserving the current level difference.
3
(Meter)
8
9
3
(Meter)
8
9
3
(Meter)
8
9
9