Int 16 Fn 6F11  - Hp Vectras Rs/20c And Rs/25c - Get Memory Caching State  [b]

   AX = 6F11h

Return: AH = 00h (successful)
   AL bit 0 = cache state
       0 cache disabled
       1 cache enabled

See Also: AX=6F00h,AX=6F0Fh,AX=6F10h