Int 31/AX=FF00h

CauseWay - Info - GET SYSTEM SELECTORS/FLAGS

AX = FF00h

Return:
AX = selector for flag address space (base 00000000h, limit 4GB)
BX = selector for current PSP segment (limit 0100h)
(E)CX = size of DOS transfer buffer (max 64K)
DX = real-mode segment address of DOS transfer buffer
ES:(E)SI = protected-mode address of DOS transfer buffer
EDI = system flags (see #03162)

Program: CauseWay is a 386 DOS extender by Michael Devore and John Wildsmith for use with Watcom C++ or assembly language programs

Notes: The entire transfer buffer can be addressed with a 16-bit offset in protected mode. CauseWay always maps selector 0040h to the BIOS data segment at real-mode segment 0040h; when not running under a DPMI host, CauseWay also provides selectors A000h, B000h, and B800h mapped to video memory

See Also: AX=FF25h

Bitfields for CauseWay system flags: Bit(s) Description (Table 03162) 0 32-bit code 1 virtual memory manage enabled

3-2 mode:
00 raw extended memory, 01 VCPI, 10 DPMI 4 DPMI available 5 VCPI available 6 no memory managers

7 application descriptor table type:
0 = GDT, 1 = LDT 14-8 reserved 15 debugging engine present

Category: DOS Extenders - Int 31h - C

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