Yamaha Electone EL-87 Owner's Manual page 23

Hold
This button allows you to keep the LCD display at the current
function. Normally, if the buttons of other functions are pressed,
the LCD will switch to those functions. To keep this from
happening, press the Hold button; the button's LED will remain lit
as long as Hold is in effect. Press the button again to cancel Hold.
Coarse Button
This button allows you to make quick "jumps" when changing values
(of the parameters with bar indications). While holding the Coarse
button down, press the Data Control button corresponding to the
value you wish to change; the values will change rapidly toward
the maximum or minimum.
19