Format of data at start of STACKS code segment (if present)

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Offset	Size	Description
00h	WORD	???
02h	WORD	number of stacks (the x in STACKS=x,y)
04h	WORD	size of stack control block array (should be 8*x)
06h	WORD	size of each stack (the y in STACKS=x,y)
08h	DWORD	pointer to STACKS data segment
0Ch	WORD	offset in STACKS data segment of stack control block array
0Eh	WORD	offset in STACKS data segment of last element of that array
10h	WORD	offset in STACKS data segment of the entry in that array for the next stack to be allocated (initially same as value in 0Eh and works its way down in steps of 8 to the value in 0Ch as hardware interrupts pre-empt each other)

Note:

The STACKS code segment data may, if present, be located as follows:

DOS 3.2 : The code segment data is at a paragraph boundary fairly early in the IBMBIO segment (seen at 0070:0190h).

DOS 3.3 : The code segment is at a paragraph boundary in the DOS data segment, which may be determined by inspecting the segment pointers of the vectors for those of interrupts 02h, 08h-0Eh, 70h, 72-77h which have not been redirected by device drivers or TSRs.

DOS 4.0+ : Identified by sub-segment control block type "S" within the DOS data segment.

See Also:

#01636,INT B4"STACKMAN"