P - Enter a point:
  Press 'p' then move the cursor to the desired location and left click to place the point.

L - Draw a line:
  Press 'l' then move the cursor to the desired starting point and left click to start the line. Move to the end point and left click to create the line.

T - Enter text:
  Press 't' then type to enter your desired text. Use the mouse to place the text and left click to finish.

S - Change scale:
  Press 's' to cycle through the available scales.

C - Mk. 8 computer:
  Press 'c' open the mk. 8 computer. Click and drag to turn the inner ring, much like rotating the graph. Pres 'c' or Escape to close the computer.

K - Show/hide calipers:
  Press 'k' to show the calipers. You can reposition them by dragging the base line. (The one with the triangles.) You can adjust the spacing by dragging the end line.
  Press 'k' again to turn them off.

X - Show/hide crosshairs:
  Press 'x' to display crosshairs centered on the cursor. Useful for precisely locating points on a plot.

M - Show/hide map:
  Press 'm' to display a map of the Marianas islands. When using the map you should use a center of 15°N, 145°E.

Select item:
  Right click to select an item. The item nearest the cursor will be shown in red. Left clicking will toggle between the two items closest to the cursor. Once your desired
  item is selected it can be modified by pressing 'e' or deleted by pressing 'd'. Right click or press Escape to end selection.

Set graph center:
  Rotate the graph to the desired center latitude. Rotate right for north or left for south latitudes. Press 'k' to display the calipers and enter the center longitude in
  the caliper distance box to the bottom right of the graph. The range line should be left of the base line for west longitudes or to the right for east. Once set press
  CTRL-C to center the graph. Once centered the latitude and longitude of the cursor will be displayed to the upper right of the graph.

Hash marks:
  You can place hash marks at 10 minute intervals on a line. Open the calipers and enter the ground speed in the range box. Right click and move the cursor
  to select the desired line and then press 'h'.