Extended-Function Dispatch Table - Windows 3.1 Device Drivers

Windows 3.1 Device Drivers (ddag31qh.hlp) (Table of Contents; Topic list)

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Extended-Function Dispatch Table

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A display grabber also includes several extended functions. Windows calls
the extended functions by supplying an extended-function number in the AX
register when it calls the standard function InquireGrab. The InquireGrab
function uses the extended-function dispatch table, consisting of function
offsets, to transfer control to the desired function. This table differs
from the standard-function dispatch table because it contains offsets, not
jump instructions.
 
The extended-function dispatch table has the following form:
 
ExtFuncTable    label   word
        dw      Obsolete        ;function 0FFF4h
        dw      Obsolete        ;function 0FFF5h
        dw      Obsolete        ;function 0FFF6h
        dw      Obsolete        ;function 0FFF7h
        dw      GetBlock        ;function 0FFF8h
        dw      Obsolete        ;function 0FFF9h
        dw      GetVersion      ;function 0FFFAh
        dw      DisableSave     ;function 0FFFBh
        dw      EnableSave      ;function 0FFFCh
        dw      SetSwapDrive    ;function 0FFFDh
        dw      GetInfo         ;function 0FFFEh
        dw      Obsolete        ;function 0FFFFh
 
 
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