Output Status (Device-Driver Function 0Ah)

STATUSREQUEST STRUC

srLength db ? ;length of record, in bytes

srUnit db ? ;not used

srFunction db 0Ah ;function number

srStatus dw ? ;status

srReserved db 8 dup(?) ;reserved

STATUSREQUEST ENDS

Output Status (Device-Driver Function 0Ah) specifies whether any characters are in the device-output buffer.

This function is required for character-device drivers only.

Fields

srLength

Specifies the length, in bytes, of the STATUSREQUEST structure.

srUnit

Not used.

srFunction

Specifies the Output Status function: 0Ah.

srStatus

Specifies the status of the completed function. If the output buffer has any characters, the driver must set the busy bit (bit 9), indicating that the device is busy. If the output buffer has no characters, the busy bit must be zero. In both cases, the driver must set the done bit (bit 8).

If the function is not successful, the driver must set both the error and done bits (bits 15 and 8) and copy an error value to the low-order byte.

srReserved

Reserved; do not use.

See Also

Device-Driver Function 06h Input Status
Interrupt 21h Function 4407h Check Device Output Status