Int FF  - Pc/forth - Graphics Api - Video Status Change                    [V]

   BX = 0000h
   DS:SI -> FORTH program counter
   SS:BP -> FORTH parameter stack
   SS:SP -> FORTH return stack
   DS:DX -> FORTH video parameter area
Desc:  called to inform graphics driver of any status changes such as video
     mode changes, character color changes, graphics XOR mode turned on
     or off, etc.; also used as an installation check
Index: installation check;PC/FORTH