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2F12FFBX0006

Category: memory management
Flags: Undocumented function

INT 2F - DR DOS 6+, Novell DOS 7+ - EMM386.EXE - VIDEO MEMORY SPACE CONTROL

	AX = 12FFh
	BX = 0006h
	DX = 0000h
	CX = function
	    0000h get status of video memory space (MEMMAX /V)
	    0001h map memory into video memory space (MEMMAX +V)
	    0002h unmap memory from video memory space (MEMMAX -V)
Return: CF clear if successful
	    AX = 0000h (successful)
	    BX = segment of reserved video RAM
	    CX = segment of used video RAM
	    DX = segment of first upper MCB
Notes:	this functionality is provided by EMM386, and partially supported by
	  HIDOS.SYS
	BL specifies which program handles the call, BH is the function number
BUG:	4DOS 5.51(a) often hangs the system (reported to be reproducable), if
	  MEMMAX +V is issued from the 4DOS prompt.  To avoid this, one should
	  temporary load COMMAND.COM followed by MEMMAX +v , starting the
	  application, MEMMAX -v and EXIT.  4DOS 5.5c does not show this
	  phenomena on the same systems where 5.51a hangs.
SeeAlso: AX=D201h/BX=4849h


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