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#define INCL_VIO
 
USHORT VioGetPhysBuf(pviopb, usReserved)
PVIOPHYSBUF pviopb;    /* pointer to structure for physical video buffer */
USHORT usReserved;     /* must be zero                                   */
 
The VioGetPhysBuf function retrieves the selector of the physical video
buffer. The physical video buffer contains the text or graphics information
that defines the current screen image. In text mode, the buffer contains the
character and attribute for each character cell. In graphics mode, the
buffer is a bitmap (in one or more planes) of the image on the screen. The
content of the screen depends on the current screen mode and the type of
display adapter.
 
The VioGetPhysBuf function is a family API function.
 
Parameter   Description
────────────────────────────────────────────────────────────────────────────
 
pviopb      Points to the VIOPHYSBUF structure that specifies the address
            and length of the physical video buffer, and receives the
            selector(s) used to address the video buffer.
 
usReserved  Specifies a reserved value. This parameter must be zero.
 
Return Value
 
The return value is zero if the function is successful. Otherwise, it is an
error value, which may be one of the following:
 
     ERROR_VIO_EXTENDED_SG
     ERROR_VIO_IN_BG
     ERROR_VIO_INVALID_HANDLE
 
Comments
 
Since the physical video buffer is subject to change by the current
foreground process, only the foreground process should access the buffer. To
ensure that the foreground process has complete control of the physical
buffer, use the VioScrLock function.
 
If a background process calls VioGetPhysBuf, the function will return
ERROR_VIO_IN_BG. If a background process attempts to access the physical
video buffer, it will be terminated.
 
Only a full-screen application can call the VioGetPhysBuf function. If an
application running in a VIO window calls this function, the function will
return ERROR_VIO_EXTENDED_SG.
 
Example
 
This example locks the screen, calls VioGetPhysBuf to retrieve the address
of the physical video buffer, unlocks the screen, and assigns the address of
the physical video buffer to a pointer:
 
VIOPHYSBUF viopb;
PCH pchScreen;
USHORT fStatus;
 
viopb.pBuf = (PBYTE) 0xB8000L;
viopb.cb = 4000L;
VioScrLock(LOCKIO_WAIT, (PBYTE) &fStatus, 0);
VioGetPhysBuf(&viopb, 0);
VioScrUnLock(0);
pchScreen = (PCH) MAKEP(viopb.asel[0], 0);
 
See Also
 
VioGetBuf, VioScrLock, VioScrUnLock, VioShowBuf, VIOPHYSBUF
 
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