The following video IOCtls are defined and supported by the SCREENDD$ device driver, by way of the DosDevIOCtl call. The IOCtl category code is 80h (defined as SCREENDD_CATEGORY).
The function codes within the SCREENDD_CATEGORY are:
旼컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿑unction 쿏escription � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �00h 쿒et Current Video Memory Bank � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �01h 쿞et Current Video Memory Bank � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �02h-07h 쿝eserved � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �08h 쿝eturn Adapter Video Configuration � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �09h 쿝eturn Manufacturer-Specific Adapter Data � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �0Ah 쿢pdate Adapter Video Memory Information � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �0Bh 쿝eturn Linear Address Mapped to Physical Address � 쳐컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �0Ch-7Fh 쿝eserved � 읕컴컴컴컴컨컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
An example of the DosDevIOCtl calling convention for the Screen IOCtls follows:
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int PASCAL near videoIoctl(VOID *data,VOID *parm,USHORT function)
{
unsigned hScreenDD; /* handle of SCREENDD$ dev driver */
unsigned OpenAction; /* action taken to open device */
unsigned rc; /* function return code */
if (!(rc = DosOpen(SCREENDD_NAME, (PHFILE)&hScreenDD, (PUSHORT)&OpenAction,
NO_SIZE, NO_ATTRIBUTES, OPEN_IF_EXISTS, NO_INHERIT+DENY_NONE+READ_WRITE,
RESERVED_LONG)))
{
rc = DosDevIOCtl(data,
parm,
function,
SCREENDD_CATEGORY,
(HFILE)hScreenDD);
DosClose(hScreenDD);
}
return (rc);
컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴