Int 20  P - Microsoft Windows - Vdmad - Vxd Services                       [W]

   VxD = 0004h

Note:  the desired VxD and service number are identified by the data
     immediately following the INT 20 instruction, as in:
       INT 20h
       DW  service number
       DW  VxD identifier

See Also: INT 2F/AX=1684h"DEVICE API",INT 30"Windows",#0961,#1032

(Table 0964)
Values for VDMAD (VxD 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 DMA region
 000Ah unlock DMA 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 address mode
 0016h set EISA address mode
 0017h unlock DMA 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

See Also: #0963,#2333,#2370 at INT 2F/AX=1684h/BX=0444h