Int 10 Fn EF  - Video - MSherc.com - Get Video Adapter Type And Mode       [V]

   AH = EFh

Return: DL = video adapter type
       00h original Hercules
       01h Hercules Plus
       02h Hercules InColor???
   DH = memory mode byte
       01h "half" mode
       03h "full" mode
Program: MSHERC.COM is a support program for the Microsoft Quick languages which
     makes their graphics libraries compatible with a Hercules card by
     adding video modes 08h and 88h, and supporting text in the new
     graphics modes.

Notes: while in mode 08h or 88h, INT 10 supports the Hercules card much like
     a CGA.
   MSHERC performs an installation check by setting DL=FFh and testing
     whether it has been changed on return
Index: installation check;MSHERC