1. A method comprising:
randomly selecting, by a computer executing a password manager, a first requirement for creating a password from a set of requirements;
providing the first requirement for creating the password;
receiving characters for the password;
determining whether the characters satisfy the first requirement;
providing information that indicates whether the characters satisfy the first requirement; and
randomly selecting, by the computer, a second requirement for creating the password from the set of requirements in response to the characters satisfying the first requirement, wherein the second requirement is selected independently of the first requirement.
2. The method of claim 1, wherein determining whether the characters satisfy the first requirement comprises determining whether the characters satisfy the first requirement as each of the characters are received.
3. The method of claim 1, wherein determining whether the characters satisfy the first requirement comprises:
buffering a set of received characters; and
determining whether the set of received characters satisfy the first requirement.
4. The method of claim 1, wherein providing information that indicates whether the characters satisfy the first requirement comprises providing information that indicates the characters fail to satisfy the first requirement.
5. The method of claim 1, wherein providing information that indicates whether the characters satisfy the first requirement comprises providing information that indicates the first requirement when the characters fail to satisfy the first requirement.
6. A non-transitory computer readable medium containing instructions that, when executed by a computer, cause the computer to perform a method comprising:
randomly selecting a first requirement for creating a password from a set of requirements;
providing the first requirement for creating the password;
receiving characters for the password;
determining whether the characters satisfy the first requirement;
providing information that indicates whether the characters satisfy the first requirement; and
randomly selecting a second requirement for creating the password from the set of requirements in response to the characters satisfying the first requirement, wherein the second requirement is selected independently of the first requirement.
7. The non-transitory computer readable medium of claim 6, wherein determining whether the characters satisfy the first requirement comprises determining whether the characters satisfy the first requirement as each of the characters are received.
8. The non-transitory computer readable medium of claim 6, wherein determining whether the characters satisfy the first requirement comprises:
buffering a set of received characters; and
determining whether the set of received characters satisfy the first requirement.
9. The non-transitory computer readable medium of claim 6, wherein providing information that indicates whether the characters satisfy the first requirement comprises providing information that indicates the characters fail to satisfy the first requirement.
10. The non-transitory computer readable medium of claim 6, wherein providing information that indicates whether the characters satisfy the first requirement comprises providing information that indicates the first requirement when the characters fail to satisfy the first requirement.
11. A computer comprising:
a memory to store instructions for a password manager; and
a processor, coupled to the memory, to execute the instructions, wherein the processor is configured to:
randomly select a first requirement for creating a password from a set of requirements;
provide the first requirement for creating the password;
receive characters for the password;
determine whether the characters satisfy the first requirement;
provide information that indicates whether the characters satisfy the first requirement; and
randomly select a second requirement for creating the password from the set of requirements in response to the characters satisfying the first requirement, wherein the second requirement is selected independently of the first requirement.
12. The computer of claim 11, wherein determining whether the characters satisfy the first requirement comprises determining whether the characters satisfy the first requirement as each of the characters are received.
13. The computer of claim 11, wherein determining whether the characters satisfy the first requirement comprises:
buffering a set of received characters; and
determining whether the set of received characters satisfy the first requirement.
14. The computer of claim 11, wherein providing information that indicates whether the characters satisfy the first requirement comprises providing information that indicates the characters fail to satisfy the first requirement.
15. The computer of claim 11, wherein providing information that indicates whether the characters satisfy the first requirement comprises providing information that indicates the first requirement when the characters fail to satisfy the first requirement.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A perpendicular magnetic recording medium comprising:
a substrate;
a first ferromagnetic layer on the substrate and having an out-of-plane easy axis of magnetization;
a second ferromagnetic layer having an out-of-plane easy axis of magnetization, the second ferromagnetic layer having an anisotropy field less than about 70% of the anisotropy field of the first ferromagnetic layer;
a first coupling layer between the first and second ferromagnetic layers and permitting ferromagnetic coupling of the first ferromagnetic layer with the second ferromagnetic layer;
a third ferromagnetic layer having an out-of-plane easy axis of magnetization, the third ferromagnetic layer having an anisotropy field less than about 70% of the anisotropy field of the first ferromagnetic layer; and
a second coupling layer between the second and third ferromagnetic layers and permitting ferromagnetic coupling of the second ferromagnetic layer with the third ferromagnetic layer.
2. The medium of claim 1 wherein the anisotropy field of the third ferromagnetic layer is greater than the anisotropy field of the second ferromagnetic layer.
3. The medium of claim 1 wherein the thickness of the third ferromagnetic layer is less than the thickness of the second ferromagnetic layer.
4. The medium of claim 1 wherein the substrate has a generally planar surface and wherein each of the first, second and third ferromagnetic layers is a hexagonal-close-packed material with its c-axis oriented generally perpendicular to the substrate surface and each of the first and second the coupling layers is a hexagonal-close-packed material with its c-axis oriented generally perpendicular to the substrate surface.
5. The medium of claim 1 wherein at least one of the first and second coupling layers is formed of a material selected from the group consisting of (a) a RuCo alloy with Co less than about 65 atomic percent, (b) a RuCoCr alloy with Co less than about 65 atomic percent, and (c) an alloy of Co and one or more of Cr and B with the combined content of Cr and B greater than about 30 atomic percent.
6. The medium of claim 5 wherein said at least one coupling layer further comprises one or more oxides of one or more elements selected from the group consisting of Si, Ta, Ti, Nb, Cr, V and B.
7. The medium of claim 1 wherein at least one of the first and second coupling layers comprises a material selected from the group consisting of Pt, Pd, Pt-based alloys, and Pd-based alloys.
8. The medium of 1 further comprising an underlayer of magnetically permeable material on the substrate and an exchange break layer between the underlayer and the first ferromagnetic layer for preventing magnetic exchange coupling between the underlayer and the first ferromagnetic layer.
9. The medium of claim 1 wherein each of the first, second and third ferromagnetic layers is a granular polycrystalline cobalt alloy.
10. The medium of claim 9 wherein at least one of the first, second and third ferromagnetic layers further comprises an oxide of one or more of Si, Ta, Ti, Nb, Cr, V and B.
11. The medium of claim 1 wherein at least one of the first, second and third ferromagnetic layers is a multilayer selected from the group consisting of CoPt, CoPd, FePt and FePd multilayers.
12. A perpendicular magnetic recording disk comprising:
a substrate having a generally planar surface;
an underlayer of magnetically permeable material on the substrate surface;
a first ferromagnetic layer of granular polycrystalline cobalt alloy on the underlayer and having an out-of-plane easy axis of magnetization;
a second ferromagnetic layer of granular polycrystalline cobalt alloy having an out-of-plane easy axis of magnetization, the second ferromagnetic layer having an anisotropy field less than about 70% of the anisotropy field of the first ferromagnetic layer;
a first coupling layer between the first and second ferromagnetic layers and permitting ferromagnetic coupling of the first ferromagnetic layer with the second ferromagnetic layer;
a third ferromagnetic layer of granular polycrystalline cobalt alloy having an out-of-plane easy axis of magnetization, the third ferromagnetic layer having an anisotropy field less than about 70% of the anisotropy field of the first ferromagnetic layer; and
a second coupling layer between the second and third ferromagnetic layers and permitting ferromagnetic coupling of the second ferromagnetic layer with the third ferromagnetic layer.
13. The disk of claim 12 wherein the anisotropy field of the third ferromagnetic layer is greater than the anisotropy field of the second ferromagnetic layer.
14. The disk of claim 12 wherein the thickness of the third ferromagnetic layer is less than the thickness of the second ferromagnetic layer.
15. The disk of claim 12 wherein at least one of the first and second coupling layers is formed of a material selected from the group consisting of (a) a RuCo alloy with Co less than about 65 atomic percent, (b) a RuCoCr alloy with Co less than about 65 atomic percent, and (c) an alloy of Co and one or more of Cr and B with the combined content of Cr and B greater than about 30 atomic percent.
16. The disk of claim 15 wherein said at least one coupling layer further comprises one or more oxides of one or more elements selected from the group consisting of Si, Ta, Ti, Nb, Cr, V and B.
17. The disk of claim 12 wherein at least one of the first and second coupling layers comprises a material selected from the group consisting of Pt, Pd, Pt-based alloys, and Pd-based alloys.
18. The disk of 12 further comprising an exchange break layer between the underlayer and the first ferromagnetic layer for preventing magnetic exchange coupling between the underlayer and the first ferromagnetic layer.
19. The disk of claim 12 wherein at least one of the first, second and third ferromagnetic layers further comprises an oxide of one or more of Si, Ta, Ti, Nb, Cr, V and B.
20. A perpendicular magnetic recording system comprising:
the disk of claim 12;
a write head for magnetizing regions in the ferromagnetically coupled first, second and third ferromagnetic layers of said disk; and
a read head for detecting the transitions between said magnetized regions.