Format of MultiDOS Plus 4.0 system block:
Offset	Size	Description	)
 00h	WORD	segment of system control block
 02h	WORD	redirection flag set by /NOREDIRECT
 04h	WORD	no-INT 10 flag set by /NO10
 06h	DWORD	old INT 10
 0Ah	DWORD	new INT 10
 0Eh	DWORD	pointer to WORD with current TCB offset (see #00456)
 12h	DWORD	pointer to WORD with idle task TCB offset
 16h	DWORD	pointer to WORD with foreground TCB offset (see #00456)
 1Ah	DWORD	pointer to WORD with MultiDOS TCB offset (see #00456)
 1Eh	WORD	Task Control Block size
 20h	WORD	number of TCBs
 22h	WORD	flag: EMS present
 24h	WORD	EMS page frame base segment
 26h	WORD	16K pages in EMS page frame
 28h	WORD	base segment for conventional memory tasks
 2Ah	WORD	conventional memory size in paragraphs
 2Ch	DWORD	pointer to list of queue pointers