WO2000017726A2

WO2000017726A2 - Switchable master/slave memory controller

Info

Publication number: WO2000017726A2
Application number: PCT/US1999/018849
Authority: WO
Inventors: Daehun David Chin
Original assignee: Computron
Priority date: 1998-09-18
Filing date: 1999-09-10
Publication date: 2000-03-30
Also published as: WO2000017726A3; AU6495299A

Abstract

A switching device (54) allows a user to select one of a plurality of memory devices (50 and 52) as a 'master' device, while the remaining memory devices (50 and 52) function as 'slave' devices. If a different operating system software is stored on each of the memory devices, the computer (40) will load and run the operating system stored on the master drive when the computer is first turned on. The system provides a fast and efficient method for data storage, loading of operating systems, and switching between operating systems.

Description

MULTIPLE OPERATING SYSTEM CONTROLLER FOR A COMPUTER BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a controller switch that allows a user to select one operating system from among a plurality of different operating systems. The invention also relates to a controller switch that allows a user to select one data storage device, from among a plurality of data storage devices, to act as the master data storage device.

2. Background of the Related Art In computer systems of the related art, a plurality of operating systems (e.g.,

Unix, Windows, OS/2) can be maintained on a single computer. The user can then select one of the operating systems for use at any given time. Typically, the software corresponding to the multiple operating systems are stored on a single data storage device, such as a hard disk. In this instance, the hard disk may require partitioning, where different operating systems are stored on different partitions, in order for the computer to operate properly.

An example of a background art computer system with two operating systems stored on the same hard disk is shown in Figure 1. The central processing unit 40 is connected to a display screen 42, a floppy disk drive 44, a pointing device 46, such as a mouse or a trackball, and a hard disk drive 48. The hard disk drive is partitioned, and a different operating system is stored on each partition.

A hard disk can be partitioned using conventional software to create two or more partitions on a single hard disk. While this allows the partitioned disk drive to simultaneously store two operating systems, such a configuration can result in increased wear, and even breakage of the hard disk, as well as a loss of data. The hard disk must then be repaired or replaced, and all the data stored on the disk drive may be lost. The hard disk wear problem can be quite severe in certain various circumstances. For instance, when two different language versions (i.e., Korean and English) of the -same operating system are stored on different partitioned sections of the same hard disk, the user can choose to use one or the other of the operating systems at any given time. However, because the machine-readable code is nearly identical for both versions, the computer experiences difficulty distinguishing between the different files of the two operating systems. As a result, an excessive amount of reading of the hard drive occurs as the computer attempts to distinguish between the different files of the two operating systems. The excessive amount of reading of the hard disk causes the above-mentioned wear problem.

In addition to the wear problems described above, when two operating systems are installed on the same hard disk, it can take longer for the computer to access files from the hard disk, resulting in slower operating speeds. Further, less space is available for data storage, thus decreasing the efficiency of the computer. As a result, overall system performance is negatively impacted.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a device for switching between a plurality of operating systems that substantially obviates at least one or more of the limitations and disadvantages of the related art. Another obj ect of the present invention is to provide a switching device capable of selecting an operating system from a plurality of operating systems stored on different memory devices.

Another object of the invention is to improve the efficiency and performance capabilities of a computer system that is configured to selectively run one of a plurality of different operating systems. Another object of the present invention is to provide a switching device capable of providing an effective countermeasure against losses due to the year 2000 problem (Y2K), network vandalism, computer viruses, and the like.

A device embodying the invention can be used for selecting and independently storing, loading, and operating a plurality of operating systems. A device embodying the invention can be used with a computer having a plurality of memory devices, each of which is used to store different operating system software. A device embodying the invention can also be used to switch between a main memory device and a backup memory device if the main memory device becomes corrupted to damaged. A device embodying the invention can comprise a switching device that is used to selectively designate one memory device, from among a plurality of memory devices, to be the master controlling memory device. The remaining memory devices are then designed as subordinate or secondary memory devices.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, and wherein:

Figure 1 is a block diagram of a background art computer system having two operating systems stored on different partitions of a single hard disk drive;

Figure 2 is a block diagram of a computer system using a device embodying the present invention; and

Figures 3A and 3B show a device embodying the invention in two different operational states. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In a typical personal computer system having multiple hard disk drives, one hard disk drive will be configured as the "master" drive, and the remaining disk drives will be designated as "slave" drives. When the computer is first switched on and booted up, the computer will look to the master disk drive for the operating system software. It will load the operating system software from the master disk drive, and the user can then operate the computer. Other programs and data files can be accessed from the master drive, or from the slave drives.

A controller switch embodying the present invention is intended for use with a computer system that includes at least two different memory storage devices, such as hard disk drives. The controller switch is used to selectively designate one of the memory storage devices the master drive unit, and the remaining memory devices as slave units. The user of the system can move the controller switch to different positions to change the master drive designation from one memory device to another. An example of a system utilizing a controller switch embodying the invention is shown in Figure 2. The system includes a central processing unit 40 that is connected to a display screen 42, a floppy disk drive 44, a pointing device 46, a first hard disk drive 50, and a second hard disk drive 52. A controller switch 54 is connected to the central processing unit 40 and the first and second hard disk drives 50, 52. The controller switch 54 can be set to a first position, where the first hard disk drive 50 is designated the master drive and the second hard disk drive 52 is designated the slave drive. The controller can switch also be set to a second position, where the second hard disk drive 52 is designated the master drive and the first hard disk drive 50 is designated the slave drive. If software for a first operating system is stored on the first hard disk drive 50, and software for a second, different operating system is stored on the second hard disk drive 52, the controller switch 54 can be used to switch between the operating systems. If the user wanted to operate the computer system using the first operating system, the user would place the controller switch 54 in the first position, designating the first hard disk drive 50 as the master drive. The user would then switch the computer on, or re-boot the computer. This will cause the computer to load the software for the first operating system from the first disk drive 50. If the user wanted to switch to the second operating system, the user would place the controller switch 54 in the second position, designating the second hard disk drive 52 as the master drive, then the user would re-boot the computer. This would cause the computer to load and run the software for the second operating system from the second hard disk drive 52.

A controller switch embodying the invention can also be used to maintain one hard disk drive as the normal operating hard disk drive, while a second hard disk drive is maintained as a backup. For instance, in the system shown in Figure 2, if the controller switch 54 is set so that the first hard disk drive is designated as the master drive, and the computer is also configured to periodically copy all files from the first hard disk drive 50 to the second hard disk drive 52, the second hard disk drive 52 can be maintained as a backup drive. Then, if an error occurs in the first hard disk drive 50, or if a computer virus infects the first hard disk drive 50, the operating switch 54 can be changed to the second position, and the computer re-booted. This will get the computer system up and running again using the backup files stored on the second hard disk drive 52. The use of the controller switch 54 eliminates the need to re-load backup files from floppy disks or from a tape drive.

Typically, a hard disk drive used in a personal computer is set to master or slave status based on the presence or absence of a jumper on electrical output pins on a circuit board of the hard disk drive. For instance, a jumper can be used to electrically connect two pins to designate the hard disk drive as a master drive. The absence of a jumper across the two pins will eliminate any electrical connection between the pins, thereby designating the hard disk drive as a slave drive.

Figures 3A and 3B illustrate how a controller switch embodying the invention is used to selectively designate one hard disk drive as a master drive, and another hard disk drive as a slave drive. As shown in Figure 3A, the controller switch 54 includes first and second electrical switches 56, 58. The input and output lines of the first switch 56 are connected to the two pins 51 A, 5 IB on the first hard disk drive 50 which control the master/slave status of the first hard disk drive 50. Similarly, the input and output lines of the second switch 58 are connected to the two pins 53A, 53B on the second hard disk drive 52 which control the master/slave status of the second hard disk drive 52.

As shown in Figure 3A, when the first and second electrical switches 56, 58 are in position A, the first electrical switch 56 will electrically connect the pins 51 A, 5 IB on the first hard disk drive 50 to designate the first hard disk drive 50 as the master drive. The second electrical switch 58 will prevent any electrical connection between the pins 53A, 53B of the second hard disk drive 52, to designate the second hard disk drive 52 as a slave drive.

As shown in Figure 3B, if the first and second electrical switches are set to the B position, the master/slave status of the hard disk drives is reversed. When the first electrical switch 56 is set to the B position, it will prevent any electrical connection between the pins 51 A, 5 IB of the first hard disk drive 50, to designate the first hard disk drive 50 as a slave drive. When the second electrical switch 58 is in the B position, the switch electrically connects the pins 53 A, 53B of the second hard disk drive 52, to designate the second hard disk drive as the master drive.

A controller switch as described above can be any type of electrical switching device capable of selectively designating one memory device as a master device, and other memory devices as slave devices. The switch could be a mechanical switching device such as a sliding or pole-type rotating switch, the switch could be implemented as part of an integrated circuit based device, or the switch could take the form of software.

Furthermore, although the embodiments shown in Figures 3 A and 3B illustrate hard disk drives, whose master/slave status is controlled based on the electrical connections between output pins, other types of memory devices, and other methods of controlling the master/slave status of the memory devices are also possible without departing from the spirit and scope of the invention. For instance, a controller switch embodying the invention could be used to control the master/slave status of floppy disk drives, optical disk drives, magnetic tape drives, optical tape drives, flash memory devices, bubble memory devices, semiconductor chip based memory devices, or any other type of memory device. A controller switch embodying the invention would be configured to control the master/slave status of the memory devices according to their designs. Also, although the embodiments described above have treated the controller switch as though it is a separate element, in other embodiments of the invention, the controller switch could be implemented in software which is resident in a memory device of a computer. For instance, a controller system embodying the invention could comprise software in a computer that is used to selectively designate one flash memory device as a master unit, and a second flash memory device as a slave unit. The user of such a system would control the master/slave status of the flash memory devices by executing key strokes and/or making selections with a pointing device.

Furthermore, although in the embodiments described above the controller switch is used to control the master/slave status of two hard disk drives, in other embodiments of the invention, the controller switch could control the master/slave status of more than two memory devices.

Embodiments of the present invention have various applications. As discussed above, a plurality of operating systems can be electronically isolated from each other. For example, bilingual systems for English/Chinese and English/Korean versions of an operating system can effectively be loaded, stored and operated on electronically separate hard drives in a single computer. Embodiments of the invention can also be used to allow a computer to easily and rapidly switch from a main memory device to a backup memory device. Embodiments of the invention may also be useful in dealing with disruptions caused by the year two thousand (Y2K) problem. While many Y2K software problems have been resolved, it has become apparent that a significant amount of software will not have been fixed until well after January 1, 2000. As a result, many computer users will experience software failure in operating systems and other applications.

A computer system with a controller switch embodying the invention can be used to temporarily avoid problems caused by Y2K software bugs. In this system, important data and programs would be stored on a backup disk drive, and the files would be back dated with dates that occur before January 1, 2000. Then, if a Y2K software bug causes a system error, the computer can be temporarily configured with a date earlier than January 1, 2000, the controller switch can be set to designate the backup disk drive as the master drive, and the computer can be re-started.

The present invention has various advantages. By electronically isolating "master" and "slave" drives prior to booting the computer, the BIOS of the computer automatically searches the desired drive for the desired operating system. Additionally, random access memory space is saved by re-booting the computer prior to switching between operating systems. The increased efficiency of the hard drives reduces excess wear and breakdown of the drives, as well as increasing data storage and retrieval speed. A system configured according to the invention permits more efficient storage of data, a more efficient loading of an operating system, and thus produces a computer system with greater memory storage efficiency and faster operating speeds.

The foregoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus- function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.

Claims

WHAT IS CLAIMED IS:

1. A controller for selectively controlling the master/slave status of memory devices of a computer system, wherein the controller is configured to designate a first memory device of the computer system as either a master memory device or a slave memory device, wherein the controller is configured to designate a second memory device of the computer system as either a master memory device, or a slave memory device, and wherein the controller is configured such that when the first memory device is designated as a master memory device, the second memory device is designated as a slave memory device.

2. The controller of claim 1, wherein the controller is also configured such that when the second memory device is designated as a master memory device, the first memory device is designated as a slave memory device.

3. The controller of claim 1, wherein the controller comprises: a first designating device configured to selectively designate a first memory device of the computer system as either a master memory device or a slave memory device; and a second designating device configured to selectively designate a second memory device of the computer system as either a master memory device, or a slave memory device.

4. The controller of claim 3, wherein the first designating device and the second designating device comprise first and second electrical switches, respectively.

5. The controller of claim 4, wherein the controller is configured such that the first and second electrical switches operate together in response to movement of a selector mechanism.

6. The controller of claim 3, wherein first designating device and the second designating device comprise devices for electrically coupling and de-coupling terminals of memory devices.

7. The controller of claim 1, wherein the controller is also configured to selectively designate additional memory devices of the computer system as either master memory devices or slave memory devices, and wherein the controller is configured such that only a single memory device is designated as a master memory device, and all other memory devices of the computer system are designated as slave memory device.

8. A switching device for controlling the operation of a computer system having a plurality of memory devices, wherein the switching device is configured to select one of the plurality of memory devices to be a master memory device, and the remaining memory devices to be slave memory devices, based on an input.

9. The device of claim 8, wherein the plurality of memory devices comprise a plurality of hard disk drives, and wherein the switching device is configured to select one of the hard disk drives to be a master drive and remaining hard disk drives to be slave drives, based on the input.

10. The device of claim 8, wherein different operating system software is stored on each of the plurality of memory devices, and wherein selecting one of the memory devices to be the master memory device causes the computer system to load and run the operating system software stored on the memory device that was selected to be the master memory device.

11. A computer system, comprising: a processor; a first memory device that stores first software; a second memory device that stores second software; and a user operable switching device configured to select one of the first and second memory devices to be a master memory device, and the other of the first and second memory devices to be a slave memory device based on a user input.

12. The computer system of claim 11, wherein the processor is configured to load and run the software stored on the memory device that is selected as the master memory device when the processor is first switched on, or when the processor is re-booted.

13. The computer system of claim 12, wherein the first software stored on the first memory device comprises first operating system software, wherein the second software stored on the second memory device comprises second operating system software, and wherein the processor is configured to load and run the operating system software stored on the memory device that is selected as the master memory device when the processor is first switched on, or when the processor is re-booted.

14. The computer system of claim 11, wherein the processor is configured to periodically copy files stored on the memory device that is selected as the master memory device to the memory device that is selected as the slave memory device.

15. The device of claim 11, wherein the processor is configured to backdate any data stored to at least one of the memory devices so that the stored data reflects a date that is before a user-specified date.