Microsoft KB Archive/175378

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DOC: Interrupt 2Fh Function 1684h Name-based Usage

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Q175378

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The information in this article applies to:


 * Microsoft Win32 Device Driver Kit (DDK) Windows 95, on platform(s):
 * the operating system: Microsoft Windows 95

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SUMMARY
The Windows 95 Device Driver Kit documentation describes how a 16-bit ring 3 application can retrieve the entry point for a VxD's service functions, by specifying the VxD's unique device ID. The documentation omitted an alternate way to specify a VxD by indicating its VxD name. The sample below demonstrates how to do this:

  xor   bx, bx      ; bx = 0 indicates name-based les  di, lpName  ; Name of device being queried int  2Fh

mov  word ptr [DevAddr], di   mov   word ptr [DevAddr+2], es ; ES:DI contains entry point addr or   di, word ptr [DevAddr+2] ; or contains 0:0 on error jz   Error

In the documentation of the parameters, please add

DeviceID

Identifies a virtual device. If this value is zero, then the ES:DI registers point to an 8-character space-padded case-sensitive device name. Keywords : kbdocerr

Issue type :

Technology : kbAudDeveloper kbWinDDKSearch kbWin32sSearch kbWin32DDKSearch