DE8814802U1 - Electromechanical data storage device - Google Patents

Description

/ Electromechanical data storage device

The innovation relates to an electronic data storage device, comprising a first and a second storage unit, each with a storage medium adjustable by a drive, a drive control and a write/read device associated with the storage medium, wherein the storage units are arranged in a common frame.

A data storage device of the type mentioned above, known from EP-A-69 545, comprises two functionally separate self-contained storage units. One is a hard disk drive and the other is a cassette tape drive that can be completely inserted into the frame of the hard disk drive. Both can be connected via a suitable

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interface. Since the two storage units form spatially and functionally completely independent units that can also be manufactured independently of each other, the space required for both units is still relatively high. Functionally, they behave like any two storage media that can be connected to each other via an interface.

A higher level of integration of two storage units is implemented in the data storage device described in EP-A-20 176. Here, a hard disk drive and a tape drive are also combined, with the write/read drum for the magnetic tape of the tape drive being arranged on the shaft of the hard disk drive. A functional connection is provided between the two storage units, which allows data to be transferred directly from one storage unit to the other. This embodiment enables the spatially dense and compact arrangement of the storage units. In functional terms, however, this embodiment has the disadvantage that the storage units cannot be operated independently of one another. This significantly limits the possible uses of the storage units and thus also the performance of the entire data storage device.

The innovation is based on the task of specifying a data storage device of the type mentioned above, which is spatially so compact that it does not exceed a height of 41.3 mm (so-called half height) without thereby reducing the performance of the data storage device.

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This task is solved in a new way by arranging both storage units on the two sides of a common base plate of the frame and at least parts of the electronic control circuits of both storage units on a common circuit board. This enables an extremely compact arrangement of the data storage, since the common base plate can be shaped in such a way that hollow spaces in one storage unit can be used to accommodate components of the other storage unit. This makes it possible to accommodate a hard disk drive and, for example, a tape drive in a device slot with a height of 41.3 mm, i.e. the so-called half height, which previously could only accommodate a hard disk drive alone. Instead of a tape drive, a removable disk drive (floppy disk drive) or a device for optical storage of data can also be provided, the storage medium of which is interchangeable.

Due to the spatially close arrangement of the two storage units and the accommodation of electronic circuit parts of both storage units on a common circuit board, it is possible in a particularly simple manner to also connect the storage units closely to one another functionally by connecting the two storage units to one another and to a common interface via an internal bus, via which the data storage can be connected to a data processing system, and by providing both storage units with a common execution sequence.

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Bus control with buffer function arranged in sequence control can be controlled.

The main advantage of this solution is that, on the one hand, each storage unit can be accessed via the interface, and, on the other hand, data can be exchanged between the storage units via the internal bus without data having to be transported via the interface. The bus control and the sequence control common to both storage units ensure that the time available for data transport between the interface and the individual storage units, between the storage units themselves, and between the interface and the bus control is used optimally.

Preferably, a bus protocol unit is arranged between the internal bus and the interface, isolating the latter from the internal bus. This has the task, for example, of first completely collecting and building up commands arriving via the interface and only then passing them on to the bus controller via the internal bus, in order to keep the internal bus free for internal data transport for as long as possible. A SCSI interface can be used as an interface, for example.

Preferably, a read/write memory is connected to the internal bus, which serves as a buffer for the data read from a storage unit or to be stored in a storage unit. This enables the data to be transferred easily from one storage unit to the other.

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While the hard disk drive is mainly used as background storage due to its short access times, the other storage units with their removable data carriers enable either the data on the hard disk drive to be backed up or data sets and programs to be transferred to the hard disk drive, whereby the functional connection of the two storage units via the internal bus ensures extremely short transfer times and the computer bus is not burdened.

The following description, in conjunction with the attached drawings, explains the innovation using practical examples. They show:

Fig. 1 is a block diagram of the data storage device according to the invention,

Fig. 2 shows a section through a data storage device according to a first embodiment of the innovation along line II-II in Figure 3,

Fig. 3 is a plan view of the device shown in Figure 2 in the direction of arrow A,

Fig. 4 is a plan view of the device according to Fig. 2 in the direction of arrow B,

Fig. 5 to 7 show representations corresponding to Figures 2 to 4 of a second embodiment of the data storage device according to the invention and

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Fig. 8 to 10 corresponding to Figures 2 to 4

Representations of a third embodiment of the data storage device according to the invention.

In Figure 1, two storage units are designated by the dashed rectangles 10 and 12. The storage unit 10 can be, for example, a hard disk drive, while the storage unit 12 is, for example, a removable disk or diskette drive (floppy disk drive), a tape drive or an optical storage device, as will be described in more detail with reference to Figures 2 to 10. The two storage units 10 and 12 are connected to one another via an internal bus 14 and via an interface 15 to a peripheral bus 16, which can be, for example, a SCSI bus. The connection between the internal bus 14 and the peripheral bus 16 is made via a bus protocol unit 18, _which is able to independently receive and temporarily store a command with its auxiliary parameters and by means of which the internal bus 14 is isolated from the peripheral bus 16. The data transport on the internal bus 14 is controlled by a bus controller 20 with buffer function. The bus control is connected via a processor bus 22 with a

Microprocessor 24 is connected, which is responsible for the sequence control of the entire data storage device. The microprocessor 24 contains a small internal read/write memory and receives commands from a residual value memory 26 via the processor bus 22. By separating the processor bus 22 from the internal bus 14, this can take place independently of any data transport taking place at the same time on the internal bus 14.

Each of the storage units 10 and 12 comprises a formatter 28 or 30, which communicates with the internal bus 14 and can convert the data format on the internal bus 14 into that of the storage medium and vice versa and can send data to or receive data from a data channel 32 or 34. The data channels 32 and 34 encode or decode the data between the NRZ format (non return to zero) and the write format on the storage medium. Write/read devices 36 or 38 connected to the data channels 32 and 34 write/read the encoded data to or from the respective storage medium. The storage media are each moved by a mechanism with an associated control 40 or 42, which in turn receive their commands from the microprocessor 24 via lines 44, 46 and send status messages to them.

When a command arrives from the peripheral bus 16, it is initially buffered in the bus protocol unit 18 until it has arrived in full. During this time, the internal bus 14 and the microprocessor 24 are free for other tasks. After the command has arrived in full, the microprocessor 24 is prompted to process the command and, if necessary, to send commands to the mechanical controls 4Ö and 42. To use the peripheral bus

In order to keep the data storage device free for as long as possible and to place as little strain as possible on it through processes within the data storage device, when writing information to the storage media, a read/write memory 48 connected to the internal bus 14 is first filled and only then is the respective storage medium written from this read/write memory 48. Conversely, data that is read from the storage medium is first stored in the read/write memory 48 and then transferred at maximum speed via the bus protocol unit 18 to the peripheral bus 16.

With skilful organization of the accesses by the bus controller 20, it is even possible to transfer a newly arrived command from the bus protocol unit 18 to the microprocessor 24, while at the same time one of the formatters 28 and 30 transfers data to or from the read/write memory 48.

The data paths 18, 14, 20 and 48 common to both storage units 10 and 12 as well as the central sequence control by the microprocessor 24 allow a special mode of operation which makes the data storage device shown particularly suitable for producing backup copies. Using a special command, data can be copied from one storage medium to the other without the peripheral bus 16 being burdened with the data transfer. In this case, one formatter 28, 30 fills the read/write memory 48 when reading from its storage medium, while the other (30, 28) leaves the read/write memory 48 when writing to the corresponding storage medium.

The microprocessor 24 knows for each of the mechanical controls 40, 42 when an interruption in the data flow to or from the respective storage unit 10, 12 is likely to occur (e.g. due to pulsation times, starting or braking of the belt, etc.). If these unusable times are coordinated with one another so that the read/write memory 48, which works as a buffer, is filled and emptied as evenly as possible, this results in good utilization of this buffer memory and rapid processing of this special type of command.

Figures 2 to 10 now show three embodiments of a data storage device with two storage units, which are combined with one another in a particularly space-saving manner and are functionally connected to one another in the manner described above.

The embodiment shown in Figures 2 to 4 shows a combination of a hard disk drive 50 with a tape drive 52. The hard disk drive comprises a housing lower part 54 with a base plate 56 on which the drive motor 60 carrying two magnetic disks 58 is arranged. Furthermore, a drive 62 for support arms 64, which carry the magnetic heads 66 for the individual magnetic disks 58, is mounted on the base plate 56. The housing lower part is closed by a housing cover 68. A hard disk drive of the type described above is known in its structure per se, so that further explanations of the drive are not necessary.

The basic structure of the tape drive is also known. It comprises a tape drive with a drive motor 70 and a gear 72, with motor 70

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and the elements of the gear 72 are attached or mounted on the base plate 56. As can be seen in Figures 2 and 3, the base plate 56 has a recess 74 in a corner area which projects into an unused cavity of the hard disk drive 50. This creates enough space to accommodate the tape drive motor 70 so that the tape drive 52 can be kept very flat overall.

Between an intermediate plate 76 covering the tape mechanism 70, 72 and the cover surface of a drive housing 73, a slot 80 is formed which serves to accommodate a tape cassette 82 which can be inserted into the slot 80 in the direction of arrow C in Figure 2.

The above description shows that the use of the same base plate 56 for supporting the mechanical parts of both drives 50 and 52 and the use of hollow spaces in one drive to accommodate parts of the other drive results in a very low overall height of the entire data storage device. This effect is further enhanced by the fact that the electronic controls for both drives are arranged on a common circuit board 84 which is screwed to the housing cover 68 of the hard disk drive 50 and carries an electrical connection device 86 via which both storage units 50 and 52 can be connected to a data processing system.

The embodiment according to Figures 5 to 7 differs from that according to Figures 2 to 4 only in that instead of the tape drive 52, a floppy disk drive 88 is now combined with the hard disk drive 50.

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The parts that correspond to the arrangement according to Figures 2 to 4 are again provided with the same reference numerals. The disk drive 88 is also known per se and is therefore only explained schematically. It comprises a drive motor 90 arranged on the base plate 56 for a disk 93, which can be inserted into a guide slot in the direction of arrow D in Figure 5. Write/read heads 94, which can be positioned via a positioning drive 96, are used to write and read data to and from the disk. Space was gained for accommodating the positioning drive 96 by accommodating it in a protuberance 98 of the base plate 56, which protrudes into an unused cavity of the disk drive 50. The electronic components common to the two drives 50 and 88 are in turn arranged on a circuit board 84 which is attached to the hard disk drive 50.

In the embodiment shown in Figures 8 to 10, a disk drive for an optical storage disk is combined with the hard disk drive 50. This storage unit 100, which is also known in principle, comprises a drive motor 102 for an optical storage disk 106 that can be inserted into a guide slot 104. The optical read/write head 108 can be positioned relative to the optical storage disk 106 via a positioning drive 110, the positioning drive 110 being arranged in a depression 112 of the base plate 56 that extends into the hard disk drive 50 in order to reduce the height of the entire storage arrangement. Otherwise, the embodiment according to Figures 8 to 10 corresponds to the embodiment according to Figures 2 to 4 and 5 to 7.

Claims (4)

Il · » f t» «4 ·< al * « ■ » « » 4 .t 4 t» fe* Protection claims 1. Electronic mechanism data storage device comprising a first and a second storage unit (10, 12), each with a storage medium adjustable by a drive, a drive control (40, 42) and a write/read device (36, 38) assigned to the storage medium, wherein one of the storage units is an encapsulated hard disk drive and the storage units (10, 12) are arranged in a common frame, characterized in that the storage units (50, 52; 50, 88; 50, 100) are arranged on the two sides of a common base plate (52) of the frame and at least parts of the electronic control circuits of both storage units (50, 52; 50, 88; 50, 100) are arranged on a common circuit board (84). 2. Data storage device according to claim 1, characterized in that the second storage unit is a magnetic tape storage device (52). 3. Data storage device according to claim 1, characterized in that the second storage unit is a removable disk drive (88). 4. Data storage device according to claim 1, characterized in that the second storage unit has an optical storage medium (106) to which or from which data can be transferred or removed by means of an optical write/read device (108 _; 110).