INT 20 P - Microsoft Windows - VDD - 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. = 000Ah 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 01273) Values for VDD (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 000Ah) service number: 00h get version 01h PIF state 02h get GrabRtn 03h hide cursor 04h set VMsee Virtual Machine type 05h get ModTime 06h set HCurTrk 07h message clear screen 08h message foreground color 09h message background color 0Ah message output text 0Bh message set cursor position 0Ch query access 0Dh "VDD_Check_Update_Soon" 0Eh "VDD_Get_Mini_Dispatch_Table" 0Fh "VDD_Register_Virtual_Port" DX = base I/O port number CL = number of contiguous ports??? 10h "VDD_Get_VM_Info" 11h "VDD_Get_Special_VM_IDs" Return: ESI = ??? EDI = ??? 12h "VDD_Register_Extra_Screen_Selector" 13h "VDD_Takeover_VGA_Port" DX = VGAVideo Graphics Array(Video Graphics Array) The video adapter introduced with the IBMInternational Busiuness Machines PS/2IBM PS/2, any model series of computers. I/O port number (03C2h, etc.) ECX -> routine to call on I/O access Return: ECX -> previous handler (to be jumped to at end of new handler) 14h ??? 15h ??? 16h ...last service for Windows95 SP1 SeeAlso: #01272,#01274,#02648