Anti-theft alarm for portable computer

Abstract

A laptop computer is supplied with special-purpose software that detects when the cover is being closed by an unauthorized person. When the cover is closed, an alarm sounds using the speaker integral the laptop. The closed-cover condition is detected. The software operates on either interrupt-driven devices or polled devices which have some means for detecting that the cover is closed. The software includes a password feature and a hot-key feature for overriding the alarm so that an authorized person may close the cover without disturbing other persons or to stop the alarm if the authorized person forgets to disable the alarm.

1. A method for causing a speaker to sound an audible alarm in a portable computer having a cover, a main computer body, a hinge between said cover and said body, and an interrupt vector, said method comprising:
 a) detecting foldable closing of said cover relative to said body;  
 b) causing an interrupt to occur within said portable computer;  
 c) said interrupt causing branching control to a fixed address in said interrupt vector following said detecting; and  
 d) generating said audible alarm from said speaker following said interrupt;  
 and further comprising; detecting whether said speaker is enabled; and detecting whether said alarm is activated by an authorized user.  
 
     
     
       2. The method according to  claim 1 , wherein a computer designer assigns said fixed address in said interrupt vector for interrupt handling said interrupt upon detection of said foldable closing of said cover to said body. 
     
     
       3. The method according to  claim 2 , said fixed address in said interrupt vector comprising an original address for branching control of said portable computer upon occurrence of said interrupt upon detection of said foldable closing of said cover to said body. 
     
     
       4. The method according to  claim 3 , further comprising a first instruction segment at said original address contained in said fixed address in said interrupt vector, control branching to said instruction segment of said portable computer upon detecting said foldable closing of said cover to said body. 
     
     
       5. The method according to  claim 4 , further comprising a second instruction segment. 
     
     
       6. The method according to  claim 5  wherein said second instruction segment is located at a second address. 
     
     
       7. The method according to  claim 6 , wherein said second instruction segment causes said speaker to generate said audible alarm. 
     
     
       8. The method according to  claim 7 , further comprising trapping said interrupt caused by said foldable closing of said cover of said portable computer. 
     
     
       9. The method according to  claim 8 , wherein said trapping occurs at boot time. 
     
     
       10. The method according to  claim 9 , wherein said interrupt is trapped by resetting said original address in said interrupt vector to an indirect address of said second address of said second instruction segment. 
     
     
       11. The method according to  claim 10 , wherein said detecting of said foldable closing of said cover occurs subsequent to boot time. 
     
     
       12. The method according to  claim 11 , wherein a volume for said alarm is set by said authorized user. 
     
     
       13. The method according to  claim 12 , wherein said authorized user may deactivate said alarm. 
     
     
       14. The method according to  claim 13 , wherein said authorized user may select one of a plurality of passwords for deactivating said alarm. 
     
     
       15. The method according to  claim 13 , wherein said authorized user may select one of a plurality of hot-keys for deactivating said alarm. 
     
     
       16. The method according to  claim 12 , wherein said authorized user may activate said alarm. 
     
     
       17. The method according to  claim 16 , wherein said authorized user may select one of a plurality of passwords for activating said alarm. 
     
     
       18. The method according to  claim 16 , wherein said authorized user may select one of a plurality of hot-keys for activating said alarm. 
     
     
       19. A method for causing a speaker to sound an audible alarm in a portable computer having a cover, a main computer body, a hinge between said cover and said main computer body, a status location indicating foldable closing of said cover against said body, and an instruction segment, said method comprising:
 a) polling said status location to detect said foldable closing of said cover against said main computer body;  
 b) causing execution of said instruction segment following detection of said status location indicating said foldable closing of said cover against said main computer body;  
 c) said instruction segment generating said audible alarm;  
 and further comprising: detecting whether said speaker is enabled; and detecting whether said alarm is activated by an authorized user.  
 
     
     
       20. The method according to  claim 19 , wherein a volume for said alarm is set by said authorized user. 
     
     
       21. The method according to  claim 20 , wherein said authorized user may deactivate said alarm. 
     
     
       22. The method according to  claim 21 , wherein said authorized user may select one of a plurality of passwords for deactivating said alarm. 
     
     
       23. The method according to  claim 21 , wherein said authorized user may select one of a plurality of hot-keys for deactivating said alarm. 
     
     
       24. The method according to  claim 20 , wherein said authorized user may activate said alarm. 
     
     
       25. The method according to  claim 24 , wherein said authorized user may select one of a plurality of passwords for activating said alarm. 
     
     
       26. The method according to  claim 24 , wherein said authorized user may select one of a plurality of hot-keys for activating said alarm. 
     
     
       27. A method for causing a speaker to sound an audible alarm in a portable computer having a cover, a main computer body, a hinge between said cover and said body, the method comprising:
   detecting foldable closing of the cover relative to the main computer body of the portable computer;        detecting whether the speaker is enabled;        detecting whether an alarm instruction is activated; and        generating the audible alarm from the speaker if the alarm instruction is activated, the speaker is enabled, and a foldable closing is detected.     
     
     
       28. The method of  claim 27  wherein the step of detecting foldable closing comprises:
   trapping a interrupt associated with a closed position of the cover relative to the main computer body; and        activating the alarm instruction when the cover is closed.     
     
     
       29. The method of  claim 27  wherein the step of detecting foldable closing comprises:
   causing an interrupt to occur within the portable computer when the cover is closed; and        causing branching control based on the interrupt to a fixed address in said interrupt vector.     
     
     
       30. The method of  claim 27  wherein the step of detecting foldable closing comprises:
   triggering a microswitch while the cover is foldably closing; and        executing the alarm based on a signal from the microswitch.     
     
     
       31. The method of  claim 27 , wherein before the step of detecting foldable closing, the method further comprising:
   executing a portion of the alarm instruction during a boot process of the portable computer.     
     
     
       32. The method of  claim 27  wherein the step of detecting foldable closing comprises:
   polling a status indicator associated with the foldable closing of the cover; and        executing an instruction segment when the status indicator is true.     
     
     
       33. The method of  claim 27  wherein a volume for the audible alarm is set by an authorized user. 
     
     
       34. The method of  claim 27  wherein an authorized user may deactivate the audible alarm. 
     
     
       35. The method of  claim 27  wherein an authorized user may deactivate the alarm instruction. 
     
     
       36. The method of  claim 34  wherein the authorized user uses a password to deactivate the audible alarm. 
     
     
       37. The method according to  claim 34  wherein the authorized user uses one or more hot- keys to deactivate the audible alarm.   
     
     
       38. The method according to  claim 27  wherein before detecting foldable closing, the method further comprising:
   executing an instruction segment according to an action taken by an authorized user, the instruction segment for activating the alarm instruction.     
     
     
       39. A method for causing a speaker to sound an audible alarm in a portable computer having a cover, a main computer body, a hinge between the cover and the main computer body, the method comprising:
   executing an alarm instruction for monitoring a position status of the cover relative to the main computer body;        detecting an unauthorized closing of the cover;        detecting whether the speaker is enabled;        detecting whether the alarm is activated; and        generating an audible alarm programmatically if the speaker is enabled, the alarm is activated, and an unauthorized closing of the cover is detected.     
     
     
       40. The method of  claim 39  wherein the step of detecting an unauthorized closing of the cover comprises:
   trapping a cover - closed interrupt; and        triggering an alarm sequence when the status of the cover - closed interrupt changes.     
     
     
       41. The method of  claim 39  wherein the step of executing the alarm instruction comprises:
   executing a portion of the alarm instruction segment with a boot process of the portable computer.     
     
     
       42. The method of  claim 39  wherein the step of executing the alarm instruction comprises:
   executing automatically the alarm instruction segment with the operating system of the portable computer.     
     
     
       43. The method of  claim 39  wherein the step of executing the alarm instruction comprises:
   executing the alarm instruction segment by an action of an authorized user.