Format of PC-MOS/386 Task Control Block:
Offset	Size	Description	)
 00h	BYTE	signature byte "H" if allocated from system memory pool
 01h	BYTE	header block ID, "T" = TCB
 02h	WORD	length of block in paragraphs
 04h	WORD	segment address of next header block (0000h if last)
 06h	WORD	segment address of previous header block (0000h if first)
 08h	WORD	pointer to next TCB
 0Ah	WORD	pointer to previous TCB
 0Ch	WORD	pointer to associated TCB (if applicable)
 0Eh	WORD	reserved
---TCB---
 10h	WORD	TCB task ID
 12h	WORD	native context save area
 14h	WORD	start address of task
 16h	WORD	end address of task
 18h	BYTE	task priority
 19h	BYTE	task time slice
 1Ah	BYTE	"TCBWAIT" run status of task
 1Bh	BYTE	"TCBSTAT" what the task is waiting for
 1Ch	DWORD	address of polling routine
 20h	BYTE	error code from last function call
 21h 11 BYTEs	name of currently executing task
 2Ch  4 BYTEs	???
 30h	BYTE	keyboard disabled if bit 1 set
 31h	BYTE	current shift state and toggles
 32h  2 BYTEs	???
 34h	BYTE	current video mode
 35h	BYTE	current video page
 36h	BYTE	number of text columns per screen
 37h	BYTE	number of text rows per screen
 38h	WORD	length of video buffer
 3Ah	WORD	video page length
 3Ch	WORD	apge start address in video RAM
 3Eh  4 WORDs	current cursor positions for four screen pages
 46h  8 BYTEs	???
 4Eh	WORD	current cursor type
 50h	BYTE	current palette setting
 51h	BYTE	original video mode
 52h	BYTE	start CRT row (00h or 01h)
 53h	BYTE	video RAM in task active
 54h	WORD	handle of video save area
 56h	WORD	page count of video save area
 58h	WORD	segment address of video save area
 5Ah	WORD	poitner to first Task File Block (see #04009)
 5Ch	WORD	pointer to first Current Directory Block (see #04012)
 5Eh	WORD	pointer to active Current Directory Block (see #04012)
 60h	BYTE	number of drives
 61h	BYTE	current drive (0=A:, etc.)
 62h	DWORD	disk transfer address
 66h  4 BYTEs	???
 6Ah	BYTE	verify flag (nonzero = on)
 6Bh	BYTE	break flag (nonzero = on)
 6Ch	WORD	share/lock retry count
 6Eh	WORD	ticks between share/lock retries
 70h	BYTE	remote printer flags (see #04007)
 71h	BYTE	ETX/ACK delay count
 72h	WORD	spooler segment address
 74h  2 BYTEs	???
 76h  3 BYTEs	remote printer redirection for LPT1 through LPT3 (see #04008)
 79h  2 BYTEs	???
 7Bh	DWORD	offset of username in TCB
 7Fh	BYTE	current output class
 80h  7 BYTEs	protection access rights, 2 bits per class (writeable!)
 87h 122 BYTEs	???
101h	BYTE	TCB sleep downcounter value
102h 20 BYTEs	???
116h	BYTE	last scan code
	...
5D0h	DWORD	far pointer to Device Driver Terminal's entry point
5D4h	WORD	offset of logical screen
5D6h	WORD	segment of logical screen
5D8h	WORD	cursor offset within page
5DAh	BYTE	screen columns
5DBh	WORD	async port number (0000h = none)
5DDh	DWORD	physical baudrate
5E1h 19 BYTEs	reserved for Device Driver Terminal (DDT)
	...
7A6h	DWORD	far pointer to unregister calling chain