BLINKER OVERLAY OPSIZE        Request size for overlay pool
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 Purpose  : Request a size for the overlay pool

 Syntax   : BLINKER OVERLAY OPSIZE <niSize>

 Default  : 40 kb

 Example  : # Increase the overlay pool size to 60kb
            BLINKER OVERLAY OPSIZE 60

 This command is used to set the operating size of the overlay pool at run
 time in kb. It can be set to any value between 12 and 128. The default
 operating size is 40kb. This may be made smaller to save memory or larger to
 reduce the number of disk accesses made by the overlay manager to re-load
 overlaid procedures.

 When overlays are specified in the link script file, Blinker will determine
 the size of the smallest possible overlay pool by adding approximately 8kb
 to the size of the largest overlay unit (a segment for most compilers). This
 minimum value will be displayed along with the value specified in the
 BLINKER OVERLAY OPSIZE command. If the minimum value is greater than the
 value specified, the minimum value will override the value specified.

 The overlay opsize may be adjusted at runtime through the use of the BLINKER
 environment variable (see the 'Environment Variable' section in Chapter 2).
 For a discussion of how the overlay pool is used at runtime, see the
 'Overlay Pool' section in Chapter 4.

 Notes for CA-Clipper Summer '87:

 When using CA-Clipper Summer '87 and the DYNAMIC overlay allocation method
 (see BLINKER OVERLAY DYNAMIC), the minimum OPSIZE is not displayed as it
 cannot be calculated at link time. The actual OPSIZE required while
 executing the program can be determined by setting it to a small value such
 as 10kb, running through all the options of the application WITHOUT
 performing a BLIOVLCLR(), and then checking the value of the Blinker
 function BLIOVLOPS() just before quitting the program. The value returned by
 the BLIOVLOPS() function will be the minimum value for the OPSIZE.

 The reason for this is that with the DYNAMIC method all active overlays must
 remain in memory at a given time. The minimum overlay OPSIZE is therefore
 the total size of the active overlays when the program is at its deepest
 level of nesting. The method described above may be used to establish this
 value, and setting it to a smaller value will simply cause the value to be
 overridden at runtime.