Method and system for transferring compressed bytes of information between separate hard disk drive units

• US 5,438,671 A
• Filed: 07/19/1991
• Issued: 08/01/1995
• Est. Priority Date: 07/19/1991
• Status: Expired due to Term

• Current Assignee: Dell USA LP (Dell Technologies Inc.)
• Original Assignee: Dell USA LP (Dell Technologies Inc.)
• Inventors: Miles, John C.
• Primary Examiner(s): Coleman, Eric
• Application Number:
  US07/732,842
• Time in Patent Office: 1,474 Days
• Field of Search: 395/200, 395/800, 395/275, 395/425, 395/500
• US Class Current: 709/247
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 2213/0004 Parallel ports, e.g. centronics

Abstract

A two-computer system and method wherein data is transferred between the computers as complete disk images rather than as files. The transfer is made between the parallel ports of the two computers, for greater speed; amd RLL data compression is used to increase the effective rate of data transfer.

Claims

1. A method, comprising the steps of:

(a.) providing a first personal computer, comprising a first CPU, a first hard disk drive, from which data is desired to be copied, and a first parallel port;

(b.) providing a second personal computer containing a second CPU, a second hard disk drive, onto which data is desired to be copied, and a second parallel port;

(c.) connecting said first and second parallel ports together by a multi-strand cable;

(d.) running a software process on said first CPU which reads out raw data from each respective individual sector of said first drive, compresses said raw data into substantially non-repeated bytes of compressed data, and transmits said compressed data through said first parallel port;

(e.) running a software process on said second CPU which receives said compressed data through said second parallel port, decompresses said compressed data to reproduce said raw data, and writes said raw data into individual sectors of said second drive which exactly correspond to said respective sectors of said first drive; and

(f.) continuing said steps (d.) and (e.), substantially simultaneously on said first and second CPUs, until substantially all of said first drive has been imaged onto said second drive.

2. The method of claim 1, wherein said multi-strand cable makes electrical connection between said first and second ports such that data transmission lines from said first port are routed into handshaking lines at said second port.

3. The method of claim 1, wherein said first and second CPUs are both microprocessors.

4. The method of claim 1, wherein said first and second computers are both at least downwardly compatible with the Industry Standard Architecture (ISA).

5. The method of claim 1, wherein said first computer also comprises a first serial port;

and wherein said first process can branch, in accordance with user command input, to send said compressed data over said first serial port.

6. The method of claim 1, wherein said first drive presents a respective Integrated Drive Electronics (IDE) interface to said first CPU, and said second drive presents a respective Integrated Drive Electronics (IDE) interface to said second CPU.

7. The method of claim 1, wherein said second process checks drive size and parameters of said second disk, and does not overwrite any of the sectors of said second disk if the drive size and parameters of said second disk are not closely compatible with the drive size and parameters of said first disk.

8. The method of claim 1, wherein said second computer further comprises a third disk, which has more than three times the storage capacity of said second disk.

9. A method, comprising the steps of:

(a.) providing a first personal computer, comprising a first CPU, a first hard disk drive, from which data is desired to be copied, and a first parallel port;

(b.) providing a second personal computer containing a second CPU, a second hard disk drive, onto which data is desired to be copied, and a second parallel port;

(c.) connecting said first and second parallel ports together by a multi-strand cable;

(d.) running a software process on said first CPU which reads out raw data from each respective individual sector of said first drive, compresses said raw data into substantially non-repeated bytes of compressed data, and transmits said compressed data through said first parallel port;

(e.) running a software process on said second CPU which receives said compressed data through said second parallel port, decompresses said compressed data to reproduce said raw data, and writes said raw data into individual sectors of said second drive which exactly corresponds to said respective sectors of said first drive, wherein said second process checks drive size and parameters of a second disk, and does not overwrite any of the sectors of the second disk if the drive size and parameters of said second disk are not identical to the drive size and parameters of said first disk; and

(f.) continuing said steps (d.) and (e.), substantially simultaneously on said first and second CPUs, until substantially all of said first drive has been imaged onto said second drive.

10. A method, comprising the steps of:

(a.) providing a first portable personal computer, comprising a first CPU, at least one input device, at least one output device, a first hard disk drive incorporating Integrated Drive Electronics (IDE) interface electronics, at least one battery connected to power said CPU under at least some conditions, a first serial port and a first parallel port;

(b.) providing a second personal computer containing a second CPU, a keyboard, a monitor, a second hard disk drive incorporating IDE interface electronics, a second serial port, and a second parallel port;

(c.) connecting said first and second parallel ports together by a multi-strand cable, which makes electrical connection between first and second ports such that data transmission lines from said first port are routed into handshaking lines at said second port;

(d.) running a software process on said first CPU which reads out raw data from each respective individual sector of said first drive, compresses said raw data into substantially non-repeated bytes of compressed data, and transmits in parallel said compressed data through said first parallel port and into said multi-strand cable;

(e.) running a software process on said second CPU which

(i.) checks drive size and parameters of said second disk, and, IF said checking step indicates that the size and parameters of said second disk are closely compatible with the drive size and parameters of said first disk,

(ii.) receives in parallel said compressed data from said multi-strand cable and through said second parallel port,

(iii.) decompresses said compressed data to reproduce said raw data,

(iv.) and writes said raw data into individual sectors of said second drive which exactly correspond to said respective sectors of said first drive; and

(f.) continuing said steps (d.) and (e.), substantially simultaneously on said first and second CPUs, until substantially all of said first drive has been imaged onto said second drive.

11. The method of claim 10, wherein said first and second CPUs are both microprocessors.

12. The method of claim 10, wherein said first and second computers are both at least downwardly compatible with the Industry Standard Architecture (ISA).

13. The method of claim 10, wherein said first process can branch, in accordance with user command input, to send said compressed data over said first serial port.

14. The method of claim 10, wherein said second process checks drive size and parameters of said second disk, and does not overwrite any of the sectors of said second disk if the drive size and parameters of said second disk are not identical to the drive size and parameters of said first disk.

15. The method of claim 10, wherein said second computer further comprises a third disk, which has more than three times the storage capacity of said second disk.

16. A system, comprising:

a portable personal computer, comprising a CPU, at least one disk drive, a serial port, a parallel port and software, stored in a nonvolatile medium, which can control said CPU so that;

in response to a first user command sequence, said CPU executes instructions from said software to read out raw data from substantially all respective individual sectors of said drive, to compress said raw data into substantially non-repeated bytes of compressed data, and to transmit in parallel said compressed data through said parallel port;

in response to a second user command sequence, said CPU executes instructions from said software to receive in parallel data through said parallel port, to decompress said data according to a substantially predetermined algorithm to produce corresponding uncompressed data, and to overwrite said substantially all individual sectors of said drive with said decompressed data, without regard to the file structure of said drive.

17. The system of claim 16, wherein said nonvolatile medium is a floppy disk.

18. The system of claim 16, wherein said nonvolatile medium is a hard disk.

19. The system of claim 16, wherein said nonvolatile medium is a semiconductor memory.

20. The system of claim 16, wherein said portable personal computer is a laptop computer.

21. The system of claim 16, wherein, in response to a third user command input sequence, said CPU executes instructions from said software to read out raw data from each respective individual sector of said drive, to compress said raw data to produce compressed data, and to transmit said compressed data through said serial port.

22. The system of claim 16, wherein,

in response to a third user command input sequence, said CPU executes instructions from said software to read out raw data from each respective individual sector of said drive, to compress said raw data to produce compressed data, and to transmit said compressed data through said serial port;

and wherein,

in response to a fourth user command input sequence, said CPU executes instructions from said software to receive data through said parallel port, to decompresses said data according to a substantially predetermined algorithm to produce corresponding decompressed data, and to overwrite the individual sectors of said drive with said decompressed data, without regard to the file structure of said drive.

23. The system of claim 16, wherein,

in response to a third user command input sequence, said CPU executes instructions from said software to read out raw data from each respective individual sector of said drive, to compress said raw data to produce compressed data, and to transmit said compressed data through said serial port;

and wherein,

in response to a fourth user command input sequence, said CPU executes instructions from said software to receive data through said parallel port, to decompresses said data according to a substantially predetermined algorithm to produce corresponding decompressed data, and to overwrite the individual sectors of said drive with said decompressed data, without regard to the file structure of said drive; and

wherein,

in response to a fifth user command input sequence, said CPU executes instructions from said software to send executable code for said software out through said serial port.