INT 20 P - Microsoft Windows - VDMAD - VxDA virtual device driver for Windows 3.x or 95.	So called because nearly all of the Windows 3.0 drivers had names of the form "VdeviceD". See also device driver. SERVICES
	VxDA virtual device driver for Windows 3.x or 95.	So called because nearly all of the Windows 3.0 drivers had names of the form "VdeviceD". See also device driver. = 0004h
Note:	the desired VxDA virtual device driver for Windows 3.x or 95.	So called because nearly all of the Windows 3.0 drivers had names of the form "VdeviceD". See also device driver. and service number are identified by the data
	  immediately following the INT 20 instruction, as in:
		INT	20h
		DW	service number
		DW	VxDA virtual device driver for Windows 3.x or 95.	So called because nearly all of the Windows 3.0 drivers had names of the form "VdeviceD". See also device driver. identifier
SeeAlso: INT 2F/AX=1684h"DEVICE API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes.",INT 30"Windows",#01265,#01340


(Table 01268)
Values for VDMAD (VxDA virtual device driver for Windows 3.x or 95.	So called because nearly all of the Windows 3.0 drivers had names of the form "VdeviceD". See also device driver. ID 0004h) service number:
 0000h	get version
 0001h	virtualize channel
 0002h	get region information
 0003h	set region information
 0004h	get virtual state
 0005h	set virtual state
 0006h	set physical state
 0007h	mask channel
 0008h	unmask channel
 0009h	lock DMAsee Direct Memory Access region
 000Ah	unlock DMAsee Direct Memory Access region
 000Bh	scatter lock
 000Ch	scatter unlock
 000Dh	reserve buffer space
 000Eh	request buffer
 000Fh	release buffer
 0010h	copy to buffer
 0011h	copy from buffer
 0012h	default handler
 0013h	disable translation
 0014h	enable translation
 0015h	get EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). address mode
 0016h	set EISA(Enhanced Industry-Standard Architecture) A 32-bit superset of the IBMInternational Busiuness Machines ATIBM PC AT's expansion bus (which is now known as the ISA or Industry-Standard Architecture bus). address mode
 0017h	unlock DMAsee Direct Memory Access region (ND)
 0018h	"VDMAD_Phys_Mask_Channel"
 0019h	"VDMAD_Phys_Unmask_Channel"
 001Ah	"VDMAD_Unvirtualize_Channel"
 001Bh	"VDMAD_Set_IO_Address"
 001Ch	"VDMAD_Get_Phys_Count"
 001Dh	"VDMAD_Get_Phys_Status"
 001Eh	"VDMAD_Get_Max_Phys_Page"
 001Fh	"VDMAD_Set_Channel_Callbacks"
 0020h	"VDMAD_Get_Virt_Count"
 0021h	"VDMAD_Set_Virt_Count"
 0021h	...last service for Windows95 SP1
SeeAlso: #01267,#02646,#02683 at INT 2F/AX=1684h/BX=0444h