Int 2F/AX=1210h

AX = 1210h DS:DI -> first disk buffer to check

Return:
ZF clear if found DS:DI -> first unreferenced disk buffer ZF set if not found

Note: In DOS 5+, this has become essentially a NOP, invoking the same code used by AX=1224h (SHARING DELAY)

See Also: AX=120Eh

Category: DOS Kernel - Int 2Fh - D