INT 15 - MultiDOS Plus - GET TASK CONTROL BLOCK
        AH = 13h
Return: BX:AX -> task control block (see below)

Format of MultiDOS Plus v4.0 task control block:
Offset  Size    Description
 00h    DWORD   pointer to next TCB
 04h  8 BYTEs   ASCIZ task name
 0Ch  2 BYTEs   ???
 0Eh    WORD    task PSP segment
 10h    WORD    abort/suspend flags
 12h    WORD    current screen segment (see AH=0Bh,AH=0Ch)
 14h    WORD    priority level (0000h-FFFEh)
 16h    WORD    time slice counter
 18h  2 BYTEs   ???
 1Ah    WORD    suspend timer value
 1Ch    WORD    stack segment
 1Eh    WORD    stack pointer
 20h    WORD    display type
 22h    WORD    display memory
 24h  2 BYTEs   ???
 26h    WORD    termination count
 28h    WORD    equipment flag for BIO10 driver
 2Ah    BYTE    background CRT mode
 2Bh    WORD    screen width in columns
 2Dh    WORD    screen size in bytes
 2Fh    WORD    segment of physical screen memory
 31h 16 BYTEs   eight cursor positions
 41h    WORD    current cursor shape
 43h    BYTE    active display page
 44h    WORD    CRT controller I/O port base
 46h  2 BYTEs   ???
 48h    WORD    foreground task flag
 4Ah  6 BYTEs   ???
 50h    WORD    saved video segment (see AH=0Bh,AH=0Ch)
 52h    DWORD   old INT 22
 56h    DWORD   old INT 23
 5Ah    DWORD   old INT 24
 5Eh    WORD    top of memory for task
 60h  4 BYTEs   ???
 64h    WORD    DTA segment (see INT 21/AH=1Ah)
 66h    WORD    DTA offset
 68h  4 BYTEs   ???
 6Ch    BYTE    current ANSI.SYS attribute
 6Dh    BYTE    current ANSI.SYS column
 6Eh    BYTE    current ANSI.SYS row
 6Fh    BYTE    current ANSI.SYS display state
 70h    BYTE    maximum ANSI.SYS columns
 71h    BYTE    current ANSI.SYS page
 72h    WORD    saved ANSI.SYS cursor position
 74h    BYTE    ANSI.SYS parameter buffer index
 75h    BYTE    current ANSI.SYS screen mode
 76h    BYTE    ANSI.SYS wrap flag
 77h  6 BYTEs   ANSI.SYS parameter buffer
 7Dh    BYTE    ANSI.SYS keyboard DSR state
 7Eh  7 BYTEs   ANSI.SYS keyboard DSR buffer
 85h  3 BYTEs   ???
 88h 16 BYTEs   request header for DOS driver calls
 98h 14 BYTEs   ???
 A6h    WORD    segment of EMS map if EMS task
 A8h    WORD    flag: task makes EMS calls
 AAh    WORD    EMS handle for task
 ACh    WORD    keyboard shift state
 AEh 12 BYTEs   ???
 BAh    WORD    TCB of parent if child task
 BCh    WORD    termination code
 BEh    WORD    COM port number
 C0h  4 BYTEs   ???
 C4h    WORD    current IRQ number
 C6h  2 BYTEs   ???
 C8h    WORD    miscellaneous flag word
 CAh  2 BYTEs   ???
 CCh    DWORD   old INT 10
 D0h    WORD    EMS alternate map set number
 D2h 414 BYTEs  DOS current disk and directory context (optional)