Format of HMA Memory Block (DR DOS 6.0 kernel loaded in HMA): Offset Size Description ) 00h WORD offset of next HMA Memory Block (0000h if last block) 02h WORD size of this block in bytes (at least 10h) 04h BYTE type of HMA Memory Block (interpreted by MEM) 00h system 01h KEYB 02h NLSFUNC 03h SHARE 04h TaskMAX 05h COMMAND 05h var TSR (or system) code and data. DR DOS TSR's, such as KEYB, hooks interrupts using segment FFFEh instead FFFFh.