Format of DOS 3.x disk buffer:
Offset Size Description )
00h DWORD pointer to next disk buffer, offset = FFFFh if last
least-recently used buffer is first in chain
04h BYTE drive (0=A,1=B, etc), FFh if not in use
05h BYTE buffer flags (see #01651)
06h WORD logical sector number
08h BYTE number of copies to write (1 for non-FAT sectors)
09h BYTE sector offset between copies if multiple copies to be written
0Ah DWORD pointer to DOS Drive Parameter Block (see #01395 at AH=32h)
0Eh WORD unused??? (almost always 0)
10h buffered data
SeeAlso: #01649,#01652,#01653,#01655