INT 10,FE - Get DESQView/TopView Virtual Screen Regen Buffer

AH = FE

ES:DI = set to sentinel value (test for INT 10,FE supported)

returns:

ES:DI = address of DESQView/TopView video buffer, DI will always

be zero

- on return ES:DI should be tested against the original value;

the value will change if this function is supported (DESQView

or TopView loaded), otherwise it will remain unchanged

- if ES:DI changes this address can be used as the video screen

regen buffer