DOS 3.1-3.3 Specific Information

% Offset Size Description

10 word max sector size used by DOS prior to loading block

device drivers; limits allowable device sector size

12 dword pointer to DOS cache buffer header

16 dword pointer to drive information table

1A dword ~FCB~ file table pointer

1E word number of protected FCBs

20 byte number of block devices

21 byte value of LASTDRIVE command in CONFIG.SYS

22 18bytes NUL device header, first 4 bytes of device header

point to the next device in device chain

34 byte number of JOIN'ed drives