INT 10 - TopView - UPDATE SCREEN FROM SHADOW BUFFER
AH = FFh
CX = number of consecutive changed characters
ES:DI -> first changed character in shadow buffer
Notes:  avoid CX=0000h
DESQview will discontinue the automatic screen updating initiated by
AH=FEh after this call
not supported (ignored) by DESQview/X 1.0x

See also: 10FE

10FF - TopView - UPDATE SCREEN FROM SHADOW BUFFER