Offset Size Description 00h DWORD pointer to array of chain heads (see below) 04h WORD number of disk buffer chains (referred to as NDBCH below) 06h DWORD pointer to lookahead buffer, zero if not present 0Ah BYTE number of lookahead sectors, else zero (the y in BUFFERS=x,y) 0Bh WORD ??? seems always to be zero 0Dh WORD EMS handle for buffers, zero if not in EMS 0Fh WORD EMS physical page number used for buffers (usually 255) 11h WORD ??? seems always to be 1 13h WORD segment of EMS physical page frame 15h WORD ??? seems always to be zero 17h 4 WORDs EMS partial page mapping information???