/SIZE:n

    Sets the maximum size of a display to n lines. If more than n
    lines are written to the display, the oldest lines are lost as
    the new lines are added. If you omit this qualifier, the maximum
    size of the display is as follows:

    o  If you specify an existing display, the maximum size is
       unchanged.

    o  If you are creating a display, the default size is 64 lines.

    For an output or DO display, /SIZE:n specifies that the display
    should hold the n most recent lines of output. For a source or
    instruction display, n gives the number of source lines or lines
    of instructions that can be placed in the memory buffer at any
    one time. However, you can scroll a source display over the
    entire source code of the module whose code is displayed (source
    lines are paged into the buffer as needed). Similarly, you can
    scroll an instruction display over all of the instructions of
    the routine whose instructions are displayed (instructions are
    decoded from the image as needed).