Int 67 Fn 2763  - Videms.sys V1.50+ - Return Video Ram Size                [m]

   AX = 2763h
   CL = 06h
   BX = signature AAFFh

Return: AH = 00h
   DX = total amount of video RAM
Desc:  beginning with version 1.50, VIDEMS can use more adapter memory on
     some chipsets, and is no longer limited to the first 240K.

Notes: this call is not officially documented, and Conea programmers use it
     mainly for debugging purposes.