Terminate Disk Emulation (Fn 4Bh) - Western Digital T13/2132-D User Manual

T13/2132-D Revision 3

8.23 Terminate Disk Emulation (FN 4Bh)

This function returns the system to a configuration that does not include the emulated devices. If the CD booted
as a floppy disk, and the system floppy drive was pushed to be the second drive, or B:, the system floppy drive
shall now become the first drive, or A:. This could have implications for currently loaded drivers and software.
Affected drivers and software shall account for the change in this access method. If the CD booted as a hard
disk, the system hard disk was pushed to the second drive to allow the emulated hard disk to be the boot device.
If the emulation is terminated, the system hard disk shall move to become the first hard disk. This could have
implications for currently loaded drivers and software. Affected drivers and software shall account for the change
in this access method.
When the system is booted from a CD, software can determine the CD/DVD ROM drive that booted the system
by issuing Terminate Disk Emulation with AL=01h. This shall return a completed CD Specification Packet (see
table 27).
Entry
AH 4Bh
AL 00h, return status and terminate emulation, 01h = return status only, do not terminate
emulation.
DL Device number to terminate, 7Fh means terminate all devices.
DS:SI Pointer to empty CD Specification Packet (see table 27)
Exit
Carry Clear Function completed without error, emulation request was successful
Carry Set Function completed with an error, emulation not initiated
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AH Shall be cleared to zero
DS:SI Pointer to populated CD Specification Packet (see table 27)
AH Shall be set to the error code
Working Draft Enhanced Disk Drive - 4 (EDD-4)
June 23, 2010