TM 1-1510-218-10 3-9 present position in two ways.  The bottom of the page will display the aircraft's latitude and longitude.  Above the  latitude/longitude  position  is  the  present  position expressed  as  the  distance  and  radial  from  a  nearby VOR.    The  VOR  displayed  on  the  NAV  2  page  is  the nearest low or high altitude class VOR.  Terminal class VOR's   are   not   used   because   many   charts   do   not depict a compass rose around them and verifying the displayed   radial   would   be   difficult.      Verify   that   the present position shown on the NAV 2 page is correct. 1.  Left Information/Data Page 2.  Right Information/Data Page 3.  Right Page Identifier 4.  Center Segment 5.  Left Page Identifier Figure 3-5.  Present Position Page NOTE The  aircraft  must  be  located  such  that  the GPS antenna has an unobstructed view of the   sky   so   that   required   satellite   signals are    not    being    blocked.        If    necessary, position  the  aircraft away from hangars or other obstructions. f. Display   Format.      The   KLN   90B   uses   a Cathode Ray Tube (CRT) display.  The display screen is divided into segments.  These segments are formed by horizontal and vertical lines on the screen.  Most of the    time    there    are    five    segments.        Aeronautical information/data is presented on the screen in the form of pages.  A page is a presentation of specific data in an organized format.  Various page types are used to display  related  kinds  of  data.    One  page  type  is  NAV for  navigational  data  and  another  is  APT  for  airport information. When the screen is divided in five segments, the KLN   90B   displays   two   pages   at   one   time.      These pages  are  presented  in  the  upper  left  and  upper  right segments   of   the   screen.      The   lower   left  segment indicates what specific page is being displayed on the left   side.      The   lower   right   segment   indicates   what specific page is being displayed on the right side.  The page identification includes a number appended to the page  type  when  there  is  more  than  one  page  for  a page type.  There is no number displayed in the page identifier if there is only one page for a particular page type.  Whenever a + sign is part of a page identifier, there will be two or more pages, all having the same page  number,  used  to  present  all  of  the  information.   That    is,    all    of    the    information    associated    with    a particular  page  number  doesn't  fit  on  the  page  being viewed. The lower center segment of the display is used to present four different kinds of information.  The first seven  spaces  of  the  segment  indicate  the  mode  in which   the   KLN   90B   is   operating.      The   last   three spaces    are    usually    blank    but    may    contain    the characters    MSG    or    ENT.        The    characters    MSG indicate  that  there  is  a  message  to  be  viewed  on  the Message page.  The characters ENT will flash in these spaces when it is necessary to press the   ENT button.   This    segment    is    also    used    for    displaying    short operational messages called status line messages.  A complete listing of status line messages is contained in Paragraph 3-7aaj. g.    Basic   Operation   of   Controls.       The   KLN 90B has five knobs and seven buttons which are used to    perform    all    operations.        In    general,    the    two concentric knobs and the  CRSR button located on the left side of the unit are used to select pages and enter data on the left side of the screen.  Likewise, the two concentric  knobs  and  the    CRSR  button  on  the  right side  of  the  unit  are  used  to  select  pages  and  enter data on the right side of the screen. The  cursor  is  an  area  of  inverse  video  on  the screen.  On many pages, data can be added, deleted, or  changed  by  first  pressing  the  appropriate   CRSR button  to  turn  the  cursor  function  on  and  bring  the cursor on the screen.  The appropriate knobs are then used   to   enter   the   data.      When   a   cursor   is   on   the screen, the page name normally shown in the left and right    lower    segments    is    replaced    with    a    CRSR annunciation in inverse video. (1)   Page  Selection.    The  left  outer  knob  is rotated  to  select  one  of  eight  page  types  for  the  left side of the screen.  Refer to Table 3-1. NOTE The cursor function must be off. Rotating the left outer knob one detent clockwise or  counterclockwise  selects  the  page  type  marked  on the  knob  in  that  direction.    Once  the  page  type  has