INT 2F U - DOS 3+ internal - MAKE BUFFER MOST RECENTLY USED
AX = 120Fh
DS:DI -> disk buffer
SS = DOS DS (must be using a DOS internal stack)
Return: DS:DI -> next buffer in buffer list
Desc:   move the indicated buffer to the end of the disk buffer chain (least-
recently used is first); under DOS 3.3, the buffer is then moved to
the start of the disk buffer chain if it was marked unused
Note:   this function is the same as AX=1207h except that it returns a
pointer to the buffer following the specified buffer in the buffer
chain

See also: 2F1207

2F120F - DOS 3+ internal - MAKE BUFFER MOST RECENTLY USED