The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings,
The following detailed description of implementations consistent with the present invention refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead the scope of the invention is defined by the appended claims and equivalents.
Systems and methods consistent with the present invention provide mechanisms through which control of a long-term storage device, such as a hard drive, is switched between a plurality of hosts. In particular, a determination is made that the original host has “unlocked” a storage device and then control of the storage device is switched to a second host.
For ease of discussion the interfaces connecting the drive are industry standard IDE interfaces. One skilled in the art would understand that the principles taught here can be used for other interfaces, such as SATA. Additionally, one skilled in the art would understand that not all interfaces have to be of a similar type. For example, 120 and 105 could be an IDE interface while 130 could be a SATA interface.
Referring to
Switch A 140 and Switch B 150 may be comprised of CMOS Bus Switches, such as Integrated Device Technology's (IDT) IDTQS316211 24-Bit Bus Switch. Devices such as CMOS Bus Switches can isolate or connect data lines. In our device Control Circuit 110 controls these switches.
Control Circuit 110 may be comprised of a microcontroller, such as Microchip's 16LF88, with integrated FLASH, RAM and oscillator. In broad terms, the Control Circuit monitors the activity of the Xbox/original host to determine when the drive has been unlocked, and once the drive is unlocked to switch from the Xbox/original host to the forensic device/second host. There are a number of different embodiments possible to determine when the drive is unlocked and a switch may be made to the forensic device/second host.
In one embodiment, control lines 180 from the Xbox interface are connected to the Control Circuit 110. This allows the Control Circuit to determine when it is safe to switch control from one input to the other. For example, the Control Circuit can set a delay sufficient to allow the command to complete. In this way, the Control Circuit can insure that there are no pending commands that will need to be cleared after control is switched.
In another embodiment, the Control Circuit can monitor commands issued to the drive by the Xbox/original host. Once a command has been issued to unlock the drive, and the drive has provided the proper response the Control Circuit may automatically switch from Xbox/original host to forensic device/second host. This would have an additional benefit of insuring that the original host did not make any changes to the data on the drive after unlocking it.
In another embodiment, the Control Circuit performs a switch upon detecting a disable password command. The Control Circuit may insert a pre-determined delay between the detection of the disable password command and the switch.
In another embodiment, the Control Circuit performs a switch after detecting a write to command. The Control Circuit may insert a pre-determined delay between the detection of the write to command and the switch.
In a further embodiment of the above, the Control Circuit may substitute a “fake” command for the write to command from the Xbox/original host, and then perform a switch.
In another embodiment, a switch 190 is provided to provide user input. With this switch a user may specific or change whether the Xbox/original host or Forensic Device/second host is connected to the hard drive. That is, Switch 190 indicates to Control Circuit 110 whether to enable Switch A 140 and disable Switch B 150, or vice versa.
In a further embodiment, when a mechanical switch is used additional electronic “debouncing” circuitry is also used to take the irregular input from a mechanical switch and provide a clean signal.
In another embodiment feedback is provided to a user as to the state of the switches. This may be done by using Light Emitting Diodes (LED) among other methods.
The foregoing description of preferred embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. For example, systems and methods are discussed above in relation to an Xbox, the same teachings may be applied to similar devices such as an Xbox 360.
The following claims and their equivalents define the scope of the invention.
Number | Date | Country | |
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60822962 | Aug 2006 | US |