As you examine the Memory Map display, you may find that you need more
  information on those segments that interest you.  The Memory Map pop-up
  menu allows you to request segment, contents, address, and type
  definitions for an individual segment.

  A segment definition has the following form:
  cursor-address   n:init-address + length = end-address  name ( view )

  cursor-address   The address beneath your cursor when you click MB3.

  n                The number of your segment within the sequence of
                   total segments.

  init-address     The initial address of your segment.

  length           The length (in bytes) of your segment.

  end-address      The last address of your segment.

  name             The segment type name of your segment.

  view             The view of your segment:
                   block, image, region, or zone.

                   (See the 'Altering the Views and Types Display' help
                   topic for more information on views.)

  For example, the following segment definition describes the 15th
  segment in your Memory Map display, which is a segment of type LIBRTL:

          0004ECA5     15: 00040000+0001CA00=0005CA00 LIBRTL (Image)

  A contents definition consists of a partial segment definition (a
  segment definition without a cursor-address) and an ASCII
  representation of the contents of segment addresses.  For example:

  contents of: 38: 001C7000+000000C0=001C70C0
     LIBTRL\LIB$VM\LIB$GET_VM (Block)

            [ASCII representation]

  An address definition takes the form of a statement describing user
  access to a stated address.  For example:

  001C710B is read and write accessible by the user

  A type definition takes the form of a statement summarizing the total
  number of segments and total number of bytes devoted to a segment type.
  For example:

  LIBRTL\LIB$VM\LIB$GET_VM (Block) has 39 segments
     using 00002160 bytes