METHOD AND APPARATUS FOR TRANSFERRING DATA FROM A VOLATILE DATA STORE UPON THE OCCURRENCE OF A POWER FAILURE IN A COMPUTER

• US 3,801,963 A
• Filed: 09/28/1972
• Issued: 04/02/1974
• Est. Priority Date: 09/28/1972
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Kun-Chao C. Chen
• Inventors: Chen, Kun-Chao C.
• Primary Examiner(s): Shaw, Gareth D.
• Assistant Examiner(s): Chapnick, Melvin B.
• Application Number:
  US05/292,968
• Time in Patent Office: 551 Days
• Field of Search: 340/172.5,174.1R 179/1.2E 235/153A,153R,151.11
• US Class Current: 360/5
• CPC Class Codes: G06F 1/00 Details not covered by groups G06F3/00 - G06F13/00 and G06F21/00 architectures of general purpose stored program computers G06F15/76
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1441 Resetting or repowering

Abstract

A method and apparatus for transferring data from or between computers in a data processing system, such method utilizing a circuit controlled tape cartridge containing a magnetic tape. One specific application of the disclosed data transfer technique arises upon failure of a computer having volatile data storage, such failure resulting either from internal malfunctioning or from a power failure. Upon the occurrence of these types of failures in computers having volatile memories, the contents of the failing computer'"'"''"'"'s memory can only be preserved by immediate transfer to some extraneous form in which it may be stored and later reapplied, as by transferring memory content to a tape cartridge for subsequent reading into the memory of a back-up computer or for re-entry into the memory of the failing computer upon correction of the malfunction or allevation of the power failure. It is to this particular data preserving need of volatile memory computers that the method and apparatus of the present invention is particularly directed.

Claims

1. Apparatus for use in conjunction with a computer having a volatile data store and effective for preserving stored data upon the occurrence of a power failure, said apparatus comprising:

a. an auxiliary power source associated with said computer, b. a read-write head coupled to said volatile data store, c. removably mounted auxiliary data storage means cooperably disposed relative to said read-write head, said auxiliary data storage means comprising a magnetic tape cartridge equipped with a magnetic tape transferable between a supply spool and a take-up spool thereof, d. a motor cooperably disposed relative to said auxiliary data storage means and to said auxiliary power source, and e. circuit means coupled to said auxiliary power source, to said volatile data source, and to said motor and effective upon the occurrence of a power failure in said computer to preserve the data stored in said volatile data store and to activate said magnetic tape of said auxiliary data storage means relative to said read-write head such that said stored data is preservably transferred to said magnetic tape cartridge comprising said auxiliary data storage means for subsequent re-entry into said volatile data store of said computer upon the alleviation of said power failure.

2. The apparatus defined in claim 1 wherein said auxiliary power source is a constantly charging D.C. battery.

3. The apparatus defined in claim 2 wherein said motor is provided with a motor shaft and a drive roller fixed to the outermost extremity thereof.

4. The apparatus defined in claim 3 wherein said removably mounted data storage means additionally comprises a drive pulley forming a part of said magnetic tape cartridge and effective for transferring said magnetic tape as between said supply spool and said take-up spool thereof.

5. The apparatus defined in claim 4 wherein the removable mounting of said auxiliary data storage means is effectuated by means of a receiving platform associated with said computer, said receiving platform serving to support and to establish a predetermined position for said read-write head and for said motor and said drive roller thereof.

6. The apparatus defined in claim 4 wherein said magnetic tape cartridge is provided with a predetermined path of travel of said magnetic tape between said supply spool and said take-up spool, a first portion of said path of travel traversing a first cut-out formed in said tape cartridge to accommodate said read-write head and a second portion of said path of travel traversing a second cut-out formed in said tape cartridge to accommodate said drive roller of said motor in the proximity of said drive pulley, said second portion of said path of travel lying between a pair of flanges of said drive pulley adjacent the periphery thereof disposed in driven contact with said drive roller.

7. The apparatus defined in claim 5 wherein said receiving platform supporting and establishing said predetermined position of said read-write head and said motor and drive roller comprises:

a. a pair of oppositely disposed upturned guides having a pair of overturned ends fixed thereto, said guides being effective for guidably receiving said magnetic tape cartridge onto said receiving platform, b. a biased Cartridge retaining clamp effective for abuttably and yieldably retaining said cartridge in operable relationship on said receiving platform such that said drive pulley thereof is disposed in driven contact with said drive roller of said motor shaft, said clamp being manually displaceable to permit the removal and insertable installation of said tape cartridge, and c. a light source and a photo-detector associated with said circuit means and with said computer and effective for detecting a break in said magnetic tape and the complete transfer of said tape from said supply spool to said take-up spool, said light source and said photo-detector being associated also with a reflector forming a part of said magnetic tape cartridge and effective for angularly directing a beam of light from said light source to said photo-detector upon the occurrence of a break in said tape or said complete transfer of said tape from said supply spool to said take-up spool.

8. The apparatus defined in claim 4 wherein said circuit means includes a power loss detector effective for sensing a loss of power in said computer and for activating said auxiliary power source upon said sensing, said activation of said auxiliary power source being effective to feed D.C. power to said volatile data store of said computer and to activate said motor to thereby transfer said magnetic tape from said supply spool to said take-up spool past said read-write head and to thereby preservably transfer said data stored in said volatile data store to said magnetic tape of said cartridge.

9. Apparatus for transferring data as between discrete and non-interfaced computer systems each having a data store, said apparatus comprising:

a. removably mounted auxiliary data storage means individually associated with each of said computer systems, each of said auxiliary data storage means comprising a magnetic tape cartridge equipped with a magnetic tape transferable between a supply spool and a take-up spool thereof, b. means associated with each of said computer systems and effective for readably transferring data from said data store thereof to said magnetic tape of said individually associated auxiliary data storage means, and for writably transferring data from a said magnetic tape to its said data store, c. means associated with each of said computer systems and effective for activating said transferring means thereof whereby said data stored in its said data store is readably transferred to said magnetic tape cartridge of said individually associated auxiliary data storage means, and said data stored in a said magnetic tape cartridge is writably transferred to its said data store, and d. means for arranging said data stored on a said magnetic tape cartridge of a said auxiliary data storage means as readably transferred from the data store of one of said discrete and non-interfaced computer systems, such that said data may be writably transferred to the data store of another of said computer systems upon the mounting of said magnetic tape cartridge thereon.

10. The apparatus defined in claim 9 wherein each of said removably mounted auxiliary data storage means additionally comprises a drive pulley forming a part of said magnetic tape cartridge and effective for transferring said magnetic tape as between said supply spool and said take-up spool thereof.

11. The apparatus defined in claim 10 wherein the removable mounting of said auxiliary data storage means is effectuated by means of a receiving platform associated with each of said computer systems.

12. The apparatus defined in claim 11 wherein said data transferring means comprises a read-write head associated with each of said computer systems and coupled to said data store thereof, said read-write head being supported by said receiving platform of said auxiliary data storage means.

13. The apparatus defined in claim 12 wherein said activating means associated with each of said computer systems comprises:

a. an auxiliarY power source, b. a motor coupled to said auxiliary power source and comprising a motor shaft and a drive roller fixed thereto, and c. circuit means coupled to said auxiliary power source and to said motor, said motor and drive roller thereof being supported by said receiving platform of said auxiliary data storage means.

14. The apparatus defined in claim 13 wherein said circuit means includes a manually actuatable external override effective for activating said auxiliary power source and said motor such that said magnetic tape is transferred from said supply spool to said take-up spool past said read-write head and to thereby readably transfer the data stored in said data store to said magnetic tape of said auxiliary data storage means, or to writably transfer data stored on said magnetic tape to said data store of one of said computer systems.

15. The apparatus defined in claim 13 wherein said data arranging means comprises a receiving platform and an actuatable motor disassociated from any of said discrete computer systems and effective for transferring the magnetic tape of a magnetic tape cartridge from its said take-up spool to its said supply spool whereby by mounting said magnetic tape cartridge on said receiving platform of one of said computers said data stored on said tape may be writably transferred to the data store thereof.

16. In a computer having a volatile data store, the method of preserving the contents of said data store upon the occurrence of a power failure, comprising the steps of:

a. sensing said power failure by means of a power loss detector and associated circuitry forming a part of said computer, b. activating an auxiliary power source coupled to said power loss detector and to said data store to supply D.C. power to said data store and to activate a motor upon sensing a said power failure, and c. transferring, by means of said activated motor, a magnetic tape contained in a magnetic tape cartridge removably mounted on a supporting platform of said computer from a supply spool to a take-up spool past a read-write head coupled to said data store to thereby record said contents of said data store on said magnetic tape, said recorded contents being readably transferable from said magnetic tape by means of said read-write head for subsequent re-writing in said data store of said computer by manually activating said circuitry and said motor to again transfer said tape from said supply spool to said take-up spool after having first rewound said tape from said take-up spool to said supply spool.

17. In a family of discrete and non-interfaced computer systems each having a data store, the method of transferring the data from the data store of a first of said computer systems to the data store of a second of said computer systems, said method comprising the steps of:

a. manually activating an auxiliary power source of said first computer system to thereby activate an auxiliary data storage means removably mounted on said first computer system, b. readably transferring the data stored in the data store of said first computer system to a magnetic tape cartridge forming a part of said auxiliary data storage means removably mounted on said first computer system, said transfer being accomplished by the movement of a magnetic tape of said cartridge from a supply spool to a take-up spool thereof past a read-write head of said first computer system, c. removing said magnetic tape cartridge from said first computer system and rewinding said magnetic tape from said take-up spool to said supply spool, d. installing said rewound magnetic tape cartridge on said second computer system, d. manually activating an auxiliary power source of said second computer system to thereby activate said installed rewound magnetic tape cartridge, and f. writably transferring the data stored on said magnetic tape of said magnetic tape cartridge, said transfer being accomplished by the movement of said magnetic tape from said supply spool to said take-up spool past a read-write head of said second computer system.