MXPA97004391A

MXPA97004391A - Method and apparatus for controlling access to a regis disc

Info

Publication number: MXPA97004391A
Application number: MXPA/A/1997/004391A
Authority: MX
Inventors: Totsuka Takashi; Kato Yasunobu; Oya Noboru; Shioya Hiroyuki
Original assignee: Sony Corporation
Priority date: 1995-10-30
Filing date: 1997-06-13
Publication date: 1998-07-03

Abstract

The present invention relates to a method and apparatus for controlling access to a record disk, which determines a bias in such a way that a rotation delay time is minimized at an average distance of movement when a head has access to the record disk. registry. The methods and apparatuses determine the position of a data block in the record disk based on at least the determined bias, program an order of a plurality of requests to access the input disk in such a way that a quantity of movement of the head is it becomes small at the time of access to the record disk by the head, and the head has access to the record disk based on the result of programming

Description

METHODS AND APPARATUS FOR CONTROLLING ACCESS TO A RECORD DISC TECHNICAL FIELD The present invention relates to a method for controlling access to a record disk that requires high transfer speed and access to discontinuous disk positions ( random access) and a device for it. BACKGROUND OF THE TECHNIQUE Along with increasing the speed of computers, disk storage devices that allow high-speed random access have become increasingly important. In recent years, par- ticularly in multimedia technology, the focus now on so much attention, it is essential to have access to moving images and audio material stored on the disk in the form of digital data V a al speed and part r of separate positions. between them on the disk. That is, it requires a high speed of transfer and a property of real time for the storage of multimedia data such as moving images and audio. The high speed of transfer becomes naturally necessary when handling a large amount of data. of moving images and audio. In addition, the real-time property requires that an upper limit of processing time is not exceeded. For example, the movement becomes uncomfortable unless 30 blocks are deployed successively per second at constant intervals in a movie. Also, if you can not follow the disk capabilities and if there is insufficient audio data, sound interruptions and unpleasant noise are generated. In this way, if the multimedia data is not prepared and used in its specific time, the value of the information is an important way. Therefore, in the mediation process, it is important to guarantee the upper limit, that is to say that the process can be carried out in this time even in the worst case. From another far, »? , even if they meet the specifications in terms of average performance, it is possible that the data = _ arrive too late at some point. The guarantee of the maximum value of the processing time is known as the 3rd property of real time and e =. an essential function in the field of the mul imedi. In the storage of information for computers, the improvement of average performance has been the primary objective. The worst value na always remained low; that is, there is a large variation of storage processing time. This point contrasts sharply with the storage requirements for the medium. In addition, in the main fields of 3rd application of the multi edia, successive access to data in a specifically separated position (random access) must be able to be carried out at high speed. For example, video on demand (V'OD) is a system that allows a large number of visionaries to call and see the programs they want when they want it. To achieve this, it is necessary to process the requests of numerous seers in parallel and quickly prepare the data of the parties that the seer is currently viewing. For this reason, it becomes necessary to trace the sources of the films, et >; . stored in various locations on the disk, at al at speed. Also, in recent years, v? Deo- > and movies have been edited without using tapes or movies, but discs. With a tape, when you insert a scene of a few seconds in a cer position> For the minute of a program, for example, one hour, in order to avoid overwriting it is necessary to move back the entire video after the insertion position and therefore record a program. Unlike the high-speed playback of analog cassette audio tapes, the new video program record requires approximately the duration of the program, so efficiency is limited. With a disk, however, you uert that you can have random access, it is possible to place the insertion part in another position of the disc, jump once to this position and have access to the inserted video at the moment of the reproduction, and then return to the original position and follow the video playback. Taking this methodology a step further, we know of a technique where each scheme (cut) of the program is placed in different positions on the disk and tracks them at high speed at the moment of reproduction in such a way that pa rec e e eat if I was playing a single tape. By doing this, it is possible to change the scene / change lengths only by changing the order of tracking the data in the d? - =. or, and consequently the editing efficiency is ex postly a3ta. This is known as a non-linear edition. Note that, in this case too, it is necessary to physically track separate positions on the disk at high speed. Bed can be seen in these examples, in the areas of multimedia application, it is extremely important to have access to the data at high speed while tracking discontinuous positions in the iscus (this is known as random access), but the time for the movement of the head towards the desired cylinder, which is known as the search time, and the time to wait for the disk until the beginning of the 3rd appearance of the data in the cylinder, which is known as the delay time of rotation, are necessary for the movement towards unbalanced positions. These times are known as the access loading time. The greater this time compared to the time to actually access the data, the longer the time needed to transfer data from the disk and therefore the lower the performance. Now, when it is considered that the search time of the disk is Ts and the rotation delay time is Tr, the ca gga time of the disk access becomes Ts + Tr. When the disk head exists in the data and the time to actually access the Tt data, the efficiency compared to the case where there are no head jumps to a separate position becomes low as shown in the following equation (1): Tt / <; Tr + Ts + Tr > (1) It is deci, in comparison with a case in which you have access to the data on the disk sequentially 1 from the beginning to the end, in the case in which random access is made while tracking the data. data in separate positions, it is necessary to be aware of the reduction of performances by this amount. Therefore, the task with multimedia discs is to suppress performance reduction at the time of random access while maintaining the real-time property (to determine the upper limit of processing time and always guarantee a real-time operation equal to or more than short that this upper limit). In recent years, research has been conducted on the method to guarantee real-time ownership of disc access. For example, in D. Anderson, Y. Osawa, and R. Govindan, "A File System for Cantinuous Media," ACM Transac.tions on Computer Systems, vol. 10, na. 4, pgs. 311-337, 1992 (hereinafter referred to as "Anderson 92"), an attempt is made to improve the performance of a system by optimizing the ratio between the amount of the buffer to temporarily store the data read from the disk and the amount of data to be read in a single access. When it comes to the loading time of the disk access, however, to facilitate the analysis, it is considered that the worst conceivable values for both the search time and the rotation delay time occur at each random access. That is, the time when the search is made, from the internal ircunference to the outer circumference is adopted as the search time and the waiting time for exactly one rotation is adopted as the rotation delay time. Obviously, if this consideration is made, the estimate of the worst value of time - of processing is extremely safe, but such an operation is not carried out every time now and therefore the estimation of the worst value becomes very slow in comparison with the performance that it can actually be derived from the disk if such estimation has little significance as data of design. In addition, in V. Pangan and H. Vin, "Efficient Storage Technique for Digital Continuous Multimedia", IEEE Transactians on nowledge 3 nd Data Engineepng, vol. 5, no. 4, pgs. 564-573, 1993 a. continuation known as "Pangan 93"),, < and investigates how, when a video row is cut into several segments and the various segments are stored in different positions, to determine the lengths of the segments and the intervals between segments to maintain the property of the area. 1. Here too, however, when I-> jumps between segments (at the time of random access) it is considered that the worst load time is caused each time in the same way as described in "Anderson 92", therefore there is a problem if ilar. There have also been attempts to keep the worst value lower compared to these studies. they allow to grant a random access in real time with much higher performances. Each of N. Reddy and J. Wyllie, "Di k Scheduling in a Multimedia 1/0 System", ACM multimedia 93, pgs. 225-233, 1993 (hereinafter referred to as "Reddy 93"), J. Bemmel, J. Han, et al., "Delay-Sensi 1 ve Multimedia on Disk", IEEE Multi edia 1994, pp. "56 - 67, 1994 (hereinafter referred to as "Gemme3 94"), and M. Chen, D. Kandlur, and P. Yu, "Op ii za ion of the Grouped Sweeping Schedulmg (GSS) üiith Heterogeneous Multimedia Strea s", ACM Multimedia 93, pp. 235 - 242, 1993 fa continua as "Chen 93"), try to suppress the load time by using a head programming algorithm known as "EXPLORE." The "Channel ion program" is A method for reducing the search time by managing the order of access where it is necessary to have access to a plurality of positions on the disk The EXPLORING algorithm shown in Figure 1 is an algorithm in which a given plurality of input / output requests ( No. 1, No. 2, ...) are classified in the radiating direction 3 of the disk and processed sequentially. The re jective operation of the head, which will occur if the processing is carried out in the order of arrival of the applications of ent rad / sa 3 i da (No, 1, Na. 2, ...) can be and at the same time the respective search times can be reduced. With the head programming algorithm, numerous algorithms are known. These are mentioned in detail, for example, in H. Deitel, "Ope >; rat? ng System ", Add i on Wesl and, pp. 360 - 372, 19 ^ 0 All the documents of" Reddy 93"," Gemirte! 94", and" Chen 93"are based on the configuration of the use of an EXPLORING algorithm, and therefore can eliminate the search time, therefore, it is possible to decrease the worst value of the load time and guarantee a high performance in comparison with the documents "Anderson 92" and "Pangan 93." However, the only thing that the EXPLORING algorithm can suppress is the search time.No mention has been made to date regarding the reduction of the rotation delay time. "Reddy 93" considers that a special function known as a mechanism is a latency wax exists on the disk.The zero latency access mechanism is a method where the data is read successively even from the middle part of the data in? n time when the> head searches for the desired track and the front of the data that was not in time is again when the disc rotates once and this song returns, so when the disc rotates one Once, the The desired data can all be read reliably and therefore the total rotation delay and data access becomes maximum one rotation time. However, since few real disks used this mechanism, it may be that the consideration in "Reddy 93" na is rea 1 ista. On the other hand, "Gem 94" adopts a method of imaging the load time by always adding the maximum value, - as a result of the convention, that the rotation delay is an amount for which they can not be performed. control or prediction. This is to be sure, but there is a great loss, which poses a problem. In addition, the "Chen 93" document posits the rotation delay co or a correction term i. irrelevant, but this is not realistic. For example, in recent high-speed disks, the rotation site is 8.3 mS, whereas if the EXPLORE algorithm is used, the maximum value of the search time can be suppressed to approximately 6 ms or less. Therefore, the rotation delay is dominant. In addition, from the points of view of the air resistance and the. The electrical energy contained in the engine and the resultant heat generated, it is difficult to expect spectacular improvements in the speed of rotation from now on. The reduction of the rotation delay is the greatest p > robl.ema that should be solved. It is also stressed that in the usual file system for computers, the reduction of the rotation delay is important. S. N, "Improving Disk Performance Via Latency Reduc ion", IEEE TP.ansactions on Co piuters, vol. 40, no. January 1, 1991, p. 22-30, 1991 (hereinafter referred to as "Ng 91") mentions a method of reducing the average rotation delay time at the time of a reading operation by the method of preparing a copy of the data shifted in phase to the rotation rating, etc.

However, it is difficult to apply this method for multimedia applications that involve a large amount of data. PRESENTATION OF THE INVENTION An object of the present invention is to provide a method and an apparatus for controlling access to a registration disk that can perform random access at high speed while maintaining the real-time property by suppressing both the search time and the rotation delay time. Such a method for controlling access to a record disk and to an apparatus is therefore required for data storage *. multimedia, whose demand is rementad. A method for controlling access to a record disk of the present invention determines a bias such that a rotation delay time is shortened by an average distance of movement when a head has access to the record disk; the position of the block of d is determined in the regsitro disk in base, at least the bias determined; an order of a plurality of input disk access sections is programmed in such a way that the amount of movement of the head becomes small at the time of access in relation to the record disk by the head; and it performs the access to the record disk by means of the head based on the result of the programming.

In addition, the method for controlling access to a record disk of the present invention is preferably carried out by determining the position of the data block on the record disk based on a gap indicating an angular difference between the start and the end. of the same data block in addition to the bias. In addition, the method of controlling access to a record disk of the present invention preferably provides data of a plurality of combinations of bias and separations and selectively uses the combination data in accordance with the position of the record disk. In addition, the method for controlling access to a record disk of the present invention changes the size of such data block. so that the separation is constant in the entire region from the outside to the inside of the record disk. In addition, the method for controlling access to a record disk of the present invention preferably determines the compliance bias with the change in separation of the generated data block due to a radius difference of the reverse track. In addition, the method to control the. access to a record disk of the present invention preferably has the programming change of the order of a plurality of requests for access to the disk in such a way that they are arranged in the order starting from the closest one when the registration head moves from the current position towards an internal circumference or an external ircunference of the record of registration and makes the determination of the position of the data block on the record disc determine the bias and the separation in such a way that a difference between the delay time Td (L) provided by the following equation < 2 and a search time in Ts (L) yields an average search distance The one provided by the following equation becomes sufficiently small in comparison with the rotation cycle: Td < L) ~ (l .BL < thet s + theta g + 2m pi) / omega < 2) La = Lt / íN-l) < 3) where, L is a search distance in units of the number of cylinders; B is a data block number that exists in a number 1; theta s is bias in units of radians theta g is a separation in units of radians; omega is »a rotation speed (rad íap / s c) of the disk; I is the maximum value in the distance between the access positions of the two groups when the access requests are arranged in order of units of the number of 1 inds; N is the number of accesses to be processed simultaneously; and m is selected to become smaller within a range where Td (L) exceeds the search time Ts <L) in the search distance L. In addition, the method for controlling the access to a record disk of the present invention causes the programming to change the order of a plurality of disk access requests in such a way that they are arranged in the. order of appearance when the. The head moves from the current position towards the internal circumference or the outer circumference of the record disk and makes the determination of the position of the data block in the record disk determine the bias and the separation in such a way that the time of The delay Td (L) provided by the following equation (4) is always longer than the search time Ts (L) and the difference between the delay time Td (L) and the search time Ts (L) becomes sufficient. slightly smaller compared to the rotation cycle: Td < L) = < L »Bc» theta s + theta g) / omega (4) In addition, the method of access control to the record disk of the present invention divides the memory disk into first regions used when the head travels from the circumference of the pyreference. internal tendency toward the outer circumference and second regions used when the head moves from the outer circumference to the inner circumference; makes the determination of the position of the data block on the record disc determine the optimal bias and separation in the respective regions based on the direction of movement of the head; and makes the programming selectively access only the first and second regions in accordance with the direction of movement of the head. Further, the method of access control to a record disk of the present invention preferably makes the first regions and the second regions on the record disk divide the disk into a plurality of at least two parts along the direction Radial and assign both the first regions and the second regions in such a way that they are dispersed from the internal circumference to the external ircunf renc on the disk. The apparatus for controlling access to a record disk of the present invention has a bias determination device to determine the bias in such a manner that the rotation delay time in the average movement distance when the head has access to the site of registration becomes small; a data block arrangement device for determining the position of a block of data on the record disk based on at least the determined bias; and a programming device for programming the order of a plurality of input disk access requests in such a manner that the amount of head movement becomes small at the time of access of the record disk by the head, where the head plays the access to the record disk for the head based on the results of the programming. In addition, the apparatus for controlling access to a disk of the present invention preferably makes the arrangement of the data block array perform the array based on a spacing that indicates the angular difference between the start and the end of the same data block in addition to the bias. In addition, the apparatus for controlling access to a record disk in the present invention preferably makes the data block array device have data in a plurality of combinations of bias and separations and uses only the combination data in accordance with the position on the record disk. In addition, the apparatus p > In order to control access to the record disk of the present invention, it is preferred that the data block array device change the size of the data block in such a way that the separation is constant throughout the region from the external part to the internal part. of the record disk. In addition, the device to control the. Access to a record disk of the present invention preferably makes the bias determination device determine the compliance bias with the change of separation of the generated data block due to a difference in the radius of the recording track. further, he. Apparatus for controlling access to a record disk of the present invention makes the reference that the programming device changes the order of a plurality of positions for access to the disk in such a way that they are arranged in order from the closest one when the registration head it is dislodged from the current piosition to an internal ircunference or an external circumference of the record disk and causes the data block array device to determine the. bias and separation in such a way that a difference between a delay time Td (L) provided by the following equation (5) and a search time Ts (L) near an average search distance is given by the following equation ( 6) it becomes sufficiently small compared to it. rotation cycle! Td (L) - (L .B <; theta s + theta g + 2m pi) / omega (5) l.a = Lt / (N ~ l) < 6) where, L is a search distance in units of the number of cylinders; B is a data block number that exists in a cylinder; theta s is a bias in units of ra ianes theta g is a separation in units of radians; omega is a rotation speed (radian / sec) of the disk; L t is the maximum value of the distance between access positions of the two extremes when the access requests are arranged in fire in units of the number of c i 1 ndros; N is the number of accesses to be processed simultaneously; and m is selected to become e3 smaller within a range where Td (L) exceeds the search time Ts (L) in the search distance L. In addition, the apparatus for controlling access to a record disk of this invention preferably makes the programming device change the order of a plurality of requests for disk access in such a way that they are arranged in the order of appearance when the head moves from the current position towards the internal ircunference or the outer circumference of the record disk and causes the data block array device to determine bias and separation in such a way that the delay time Td (L) provided by the following equation < 7) is always greater than the search time Ts (L) and the difference between the delay time Td < L) and the search time Ts (L) becomes sufficiently small compared to the rotation cycle. Td (L) = < L "Be • theta s + theta g) / omega (7) In addition, the apparatus for controlling access to a record disk of the present invention preferably divides the memory disk into first stacked regions when the head is moved from the circumference ia internal to the outer circumference and second regions used when the head moves from the outer circumference to the inner circumference; it causes the data block arrangement device to determine the optimum bias and separation in the respective regions based on the direction of movement of; head; and makes the programming device selectively access only the first and second regions in accordance with the direction of head movement. In addition, the apparatus for controlling access to a record disk of the present invention preferably makes the first regions and the second regions on the record disk divide the. disk in a plurality of at least two parts along the radial direction and assign both the first regions and the second regions in such a way that they are dispersed from the internal ircunference to the outer circumference of the disk. In the method for controlling access to a registration disk of the present invention and to the corresponding apparatus, when the data blocks are arranged, the blocks are arranged in a disjointed manner in the cipferencial direction (they are biased), consequently the control can be carried out in such a way that the start of the desired data does not pass in the position of the head during the 3rd search operation. For this reason, it is not necessary to wait for the return of the desired data, both the search time and the rotation delay time are deleted b a, and a a. Random processing can be performed at high speed while maintaining the real-time property. In addition, in the method ci access control to a record disk of the present invention and to. In the corresponding apparatus, the bias changes between the regions used when the head is displaced from the outer circumference to the internal circumference and the regions used when the head moves from the inner circumference to the external ircumference so that it can be thus an optimum seal regardless of the duration of movement of the head, BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects and features of the present invention will be more apparent from the following description of the preferred embodiments in relation to the accompanying drawings, in where: Figure 1 is a diagram to explain the related technique; Figure 2 is a block diagram of the configuration of an apparatus for controlling access to a record disk in accordance with the first embodiment of the present invention; Figure 3 is a flow diagram for explaining the processing in the block allocator shown in Figure 2; Fig. 4 is a flow chart for explaining the processing in the pragramadar shown in Fig. 2; Figure 5 is a graph showing a relation between a search time and a search distance of a unit; Figure 6 is a diagram for explaining a block arrangement method on a disk by means of the block allocator; Figure 7 is a graph to explain the contents of the block map; Figure 8 is a view to explain the. content of the processing in step S3 presented in Figure 3; Figure 9 is a graph for explaining the processing content in step S3 shown in Figure 3; Figure 10 is a graph to explain the loading time in the case in which both the search time and the rotation delay are considered; Figures 11A, 11B and 11C are views to explain an example of distribution of accesses in the day; Figure 12 is a graph to explain the loading time in a conventional EXPLORING algorithm; Figure 13 is a graph to explain the relationship between a search distance L and a delay in the case of the use of a convex ascending function involving the sawtooth function uri3; Fig. 14 is a view for explaining the procedure in the block agitator of the apparatus for controlling access to a record disk in accordance with a second embodiment of the present invention; Fig. 15 is a flow diagram for explaining the processing of the block allocator in the apparatus for controlling access to a record disk shown in Fig. 14; and Figure 16 is. A diagram will explain the content of the block map in the apparatus to control access to a record disk shown in FIG. 13. PREFERRED MODALITY OF THE INVENTION? .

Next, the method for controlling access to a record disk according to the embodiments of the present invention and a carresponder apparatus will be explained. FIRST MODALITY Figure 2 is a block diagram of a configuration of a device for controlling access to a record disk in accordance with the present embodiment. The apparatus for controlling access to a record disk in accordance with the present embodiment is performed by programmatic operation for example on a computer.

Each block shown in Figure 2 depicts a main program module or main data structure. A block driver (device and array) 1 determined how the data is arranged on a disk 5 based on a given format parameter 10. The disk 5 can be, for example, a magnetic disk, a magneto-optical disk (MO), or a hard disk (HDD). The piarám t r > "t 10 of format includes the size of a first block of data, the distance of average head movement when programming EXPLORE, the function of search time Ts íl) of the unit to be used, and the physical format of the disk 5. The distance of average head movement is given by means of the following equation (8) from the total number of cylinders Lt of the disk and the number N of accesses processed by a browser: La = -Lt / ( N-1) (8) The search time Ts (L) of the unit is a function of the search distance L (number of cylinders), the value of which is determined by * the mechanical characteristics of the disk unit used. This example is shown in Figure 5. How many access requests are processed together by means of "n explorer s determined p > or the nature of the application used by this disk, the performance required there, the amount of buffer memory that can be implemented, and so on. The greater the number of access solids to explore together, the greater the number of random disc attempts, but e; I attach a collateral effect to it as the response volume increases as the amount of buffer memory required increases. These processors 10 for design and monitoring by a central processing unit (CPU) (not shown) that have a program of cort3 that handles the entire system, and these format parameters 10 are provided when assigning blocks 1. In the example in which the present modality is used for a non-linear edition, JM = 10 and La = 300 were supplied to the assignadsr of block 1. In addition, the size of the first data block corresponds to a of image data and is approximately 70 B (tilobites) in the case of the CCIP-601 format used in broadcasting stations, etc. And idently, this numerical value can be freely established in accordance with the object and several specifies required ions. The allocator of block 1 determines in what position of the disk the block must be placed based on the given parameter. In this example, a block is the same as a picture of an image, but the basic concept is still similar even with data obtained by dividing an MPEG or another compressed image into adequate lengths, or even with data from year. . You can have access to disk 5 for what is known as the "sector" region. A sector typically has a size of approximately 512 (bits) to approximately 4 KB. A donut-shaped region where these sectors are arranged in a circle is known as a "track". In addition, the cylindrical region that comprises the group of the ir. As tracks a plurality s? pterp? this magnetic means is known as a "cylinder". A block of video and audio data is generally larger1 than a sector, p >or consequently the assigned one! ' of blocks 1 allocates a plurality of sectors for each block. Figure 5 shows a simple e ect of a case in which there is a magnetic medium. L < A part indicated by the shading in figure 6, say an entire circumference of the track "1", and the sectors "o" to "6" of the track "2" correspond to a block. In this example, since there is only one medium, a "track" and a "cylinder" have the same meaning, but in the case of a disk drive where there are several magnetic media, if all parts of the same cylinder are completely employed, the L > birds will be assigned to use the adjacent cylinders. The allocation to the sectors is made for all the blocks. The result is written on a block map 3, whereby the assigning function of "block 1 ends. The assignor of block 1 designates a p> = => g> a sector by means of the set of cylinder number, number of medium (that ho a of medium), and the number of se .. However, in a unit of specification SCSI (Interface of Small Computer System ANSI), which has become the most popular-in recent years, serial numbers (local sector numbers, called "logical block di- ations" in SCST, but refer here to logical sector numbers so as to avoid confusion with the blocks of video data and a? dro) are provided to all sectors in the unit and this is used to access the data.For this reason, the correspondence between the log numbers determined by the unit and the physical addresses, e? s say, the cylinder numbers, number of means, and number ?. of sector, is stored in a preliminary way in a table 7 of physical addresses, The assignment of blocks 1 converts the desired physical address into the number of logical sector determined by the SCSI with reference to the table 7 of physical addresses and registers it in the apt of blocks 3.

Figure 7 shows an example of a block map. The information corresponding to the line "O" corresponds to the shaded part of the figure. 6. On the other hand, the amateur program 2 operates in the following manner. First the CPU to handle the entire system determines the program parameter 20 and provides the program parameter 2 to the programmer 2. The program parameter 20 includes a constant N which indicates how many access requests are processed together by means of a scan. When the operator gives instructions for the start of the playback of a movie image recorded in disc 5, the CPU not illustrated that has a suitable control program of the requests »to have access to, or to the blocks where the images which consist of the movie image are stored for each image. These access requests 40 are stored in the buffer of requests 4. The programmer 2 to sequentially Try a number N of access requests 40 stored in the access request buffer 4 from the access requests that arrived first, finds the positions of the data corresponding to these requests on the disk 5 with reference to the block map 3, changes the order of the access requests so that the amount of movement of the key > It is minimized, and generates an instruction for access to the ISCO 5. The access instruction is prepared to match the disk unit's third-party interface, and therefore it becomes the SCSI protocol by the controller of the controller. SCSI device 6 and is transferred to the disk 5. The data read 3 from day 5 are stored temporarily in the intermediate memory to R and then transferred to the interface of the device. When the operator gives instructions for the recording of data representing images. of p? - »lc:? l3, the unillustrated CPU having a suitable control program issues requests to access the blocks where the images constituting the movie agent are stored for each image. These access requests 4 are stored in the intermediate memory 4 of access requests. At the same time, the image data 80 constituting the film is transferred from a video interfere (not shown) to the data buffer 8, and such image data is stored emptily in the buffer memory of the video. data 8. The programmer 2 performs a number N of access requests 40 stored in the access request buffer 4 from the access requests that arrived first. Then, the programmer finds on the disk 5 the position of the data corresponding to these requests, with reference to the map of blocks 3. In addition, the programmer 2 changes the order of the access requests that the amount of movement of the The head becomes minimal, and generates an instruction for disk access 5. The command for access is made to correspond to the external interface of the disk drive, and therefore becomes the SCSI protocol through the control of the disk. 6 of the SCSI device and is transferred to disk 5. Next, a detailed explanation of the operation of the assignment of blocks 1 will be presented. How the parameter of format 10 ert figure 2, when the size of? N block, the distance average of movement of the head when performing the Exploration program, the search time function Ts (L) of the unit to be used, the physical format of disk 5 (number of cylinders, number numbers of seers on a track, and number of media that make up the cylinder) are roporci nan, the L >giver; 1 determines the position of each block on disk 5 by means of the procedures of steps SI to S5 shown in FIG. 3. In step SI, it is calculated how many image blocks exist in a cylinder (Be). The total number of sectors in a cylinder is obtained by multiplying the number of sectors, in the track the number of the media. When this is divided by the number of sectors necessary to store a block, they are Be. Theta separation g is found in step S2. The separation is the angular difference between the front sector and the final sector of the block. As the example, in the case of the block indicated by shading in figure 6, the start is the sec "or" 0"of the p > ist = t "1", and the end is the sect "6" of the track "2", therefore the = .epar ^ c? ón theta g is 5 / 12th of the ci deference, that is to say radiate of 5 p ? / 6. The Aheta s bias is found in step S3 based on the above data. Here, the theta s bias means the angular difference in the direction c i rcufet-enc la 1 between the heads of adjacent blocks ». First, by using the position of l. calteza when the reading of a certain block ends as a starting point, when it is represented by means of an ecuat. When the head of the data reaches the same angle in the circumferential direction at the position at which the head has moved from the starting point by an amount of L cylinders, the following equation (9) is obtained: Td (L) = (L »Bc« theta s + theta g + 2.m «p?) / omega (9) where, L is the search distance in units of the numbers of cylinders; Be is the number of blocks that exist in a cylinder; theta s is the bias in units of radians; theta g is the separation ert units, of radians; omega is the rotation speed (radian / sec) of the disk; and e any integer where Td (L) becomes po i t i vo. Figure 8 explains the meaning of equation (9) on the disk. In figure 8, it is considered that the access of block "0" has just finished. The head is considered to be cyclic in the direction of the angle 70 when viewed from the center. Now, when it is desired to have access to the same block "0", it is necessary to spin until the disk rotates exactly by the amount of the separator theta g, therefore the delay time theta g / omega is caused. Also, for the head in block "n", it is necessary to wait until the disk rotates exactly by the angle of the sum of the separation g from block "0" and a number n of bias blocks ). This requires a time n theta s / omega. Since the disk is rotating, the beginning of the allo reaches the position where the head placed in a time obtained by adding a whole multiple of the rotation site to the moment obtained in this way. When the head is moved by? N number of blocks, this corresponds to the movement of n / Bc cylinders in terms of the number of cylinders, therefore drawing a graph while plotting the number of cylinders on the abscissa and plotting the time of delay until reaching the beginning in the ordinate, figure 9 is obtained. The greater the bias, the greater the inclination of the group of lines. Note that, in the previous theory, it was considered that the position (angle) of the head in the ci-directional direction seen from the center was constant, regardless of the distance from the center. In 3a present, xi te? a case in which the position is not correctly constant according to the mechanism of the head, but the influence of the head is sufficiently small, and therefore it may have been ingorable. As shown in Fig. 9, the time until the end of the block ll gu or of the block in each cylinder is obtained by equation (9). However, since the head must move towards the desired cylinder d n! At this time, the delay time becomes the time until the start of the block appears the first time after the search operation. That is to say, the load type Td (L) that considers both the search type and the rotation delay. Figure 10 shows an example of this and equation 1 shows the definition of it. The actual charging time (delay time) is indicated by the thick line in Figure IO. Note that the function of the search time is indicated by the dotted line. In the figure, Trat, - »& ur? rotational ion cycle. In step 33-1, the formula of the straight line of m - in equation 3 and figure 9, that is, the formula indicated by the following equation (10), you find Td (I.) = • (I. • Be • theta s + theta g) / omega (10) the subsequent steps S3-2, S3-3, and 53- 4 are the steps, to select the theta s bias so that this straight line is always higher (larger) than the Ts (L) function of the search time and s? startc ía Try in contact with the search time function. The straight line of m = of Figure 10 is obtained using theta s selected in this picture. The plates S4 and S5 determine the position of ca to block in the disk over the entire surface of the disk by using the bias and separation obtained in this way. In step S4, the pointer of the physical address is initialized to (0/0/0) at the beginning. Then step S5 is a repeated loop for all blocks. In the loop, pi ero, in step 55-1, the logical sector number is obtained from the physical address with reference to the table of physical dimensions. In step S5-2, the information such as this and the physical address are written in the map of blocks 3. The contents of the map of block 3 apiate in figure 7. When the processing is finished, the pointer of the physical address is moved to elan e ert preparation of-1! processing of the next block. The pointer Ppa of the physical address is a > tualized in the pia so S5-3. In step S5-4, it is decided for all blocks whether or not the processing of steps S5-1 to S5-3 has been performed. If it has not been done, the processing of steps S5-1 to S5-3 is carried out for the blocks for which the process has not been carried out. Here, the arrangement of the N th block in the di is: (1) Backward from the assigned block and (2) In a region in which the sector has the angular difference from the beginning of the 0-th block plus close is defined N theta s corito the beginning. Still, the worst time to fall in the method of access control to a record disk in accordance with the current fashion will be explained. In general, the request for ^ access 40 is signaled in relation to all positions on the disk. The positions processed by an explorer have distribution irregularity as shown in Figure HA or 11B and are distributed in the reverse uniformly as shown in Figure 11C. In this example, the head is defaced before six access requests 40, consequently 5 random accesses and the associated charging times are generated. The total sum of the caga times in relation to these five random accesses becomes the worst in the case in which all accesses are evenly distributed when the load access function shows a convex upward shape (Figure 11C). When there is irregularity in the distribution, the total sum of the load times becomes smaller. In other words, when the load time in the average movement distance of the head is generated repeatedly, the total sum of the load weights becomes the worst (longest). Td (L) of Fig. 10 is a sawtooth function. If Td (L) is replaced by a function that has a convex shape upwards it is wrapped up from the top, the theory mentioned above remains basically valid. An example of the function appears in Figure 1 7. That is, the worst load time per access becomes the value obtained by reading the value Td L) in the position where the distance is La in the graph of the figure 10 (Tmax in the figure). As mentioned above, this is an approximation, but as in the example of Figure 10, the approximation of Td (L) and the envelope function from the upper parter usually coincide in that it is close to La, therefore, it can be considered at present that there is no error. further, the approximation is on the safe side (side on which the load time is estimated to be greater than it is), therefore there is no risk of imaging the worst value lower than the original value. In step 5 presented in FIG. 3, the bias was selected in such a way that some of the group of straight lines of the rotational delay provided by equation (9) are located in a higher position than the Ts function. (L) of the search time but as close as possible to this. In this way, Td (L) can be small near the distance l, and therefore the worst time of rga T ax can be made smaller. Figure 12 shows the loading time in the conventional EXPLORE algorithm. In the conventional EXPLORE algorithm too, 3? The total sum of the times of caga becomes the worst when the ones are distributed in an unformed way. However, unlike the present modality, no - >It is considered in terms of the rotation delay, therefore even after the search operation of the head is completed, it must be considered that a rotation delay of a rotational ion is generated in the worst case. For this reason, a value obtained by adding the Trot cycle of a rotation to the search time Ts (La) in La becomes the worst load time. As is evident from the comparison of Figure 12 and Figure 10, this becomes a value considerably greater than the value of the method according to the present embodiment. In these experiments, it was confirmed that the worst loading time became almost half in the present modality in comparison with the worst c a rga time obtained by the conventional EXPLORING algorithm. As explained above, in the apparatus for controlling access to a record disk according to the present embodiment, by means of the appropriate selection of the bias and the separation, it is possible to suppress the loading time TdlL) in the distance The average movement of The head has the lowest level and the rotation delay time can be made small in this way. In the flow chart illustrated in Figure 3, the size of the block at a given fixed-value, were for this purpose, the size of the block can be selected within a certain range. In this case, red separation theta g as the theta s bias can be changed, and therefore the position of the straight line can be finely controlled in such a way that it approaches the search time near La. By means of the above method, the loading time that accompanies the movement along the blocks improves greatly. When a block is large and extends in a plurality of tracks or has a plurality of cylinders, however, the time that accompanies the track time and the time of movement towards the adjacent cylinder must also be taken into consideration. The times necessary for a change of tracks and the movement towards the adjacent cylinder are constant as well, therefore giving a bias between the tracks of cylinders in such a way that the data continues just below the head after these times have passed, it is possible avoid generating a long rotation delay in the block along with the change of tracks and the movement between? the cylinders. For this purpose, the assignment of block-1 1 has another set of bias and separation for access in a block at the higher speed other than the bias and separation of movement between the processes already explained. In steps S4 and 55 in Figure 3, it is sufficient to rreg the blocks by using the last bias and sepia tion when .1 fixes a block on the disk. It is possible to make the last separation zero at all times and simply use the bias to absorb the change of tracks and movement time between the cylinders. An explanation of the operation of the programmer 2 will be given below. Figure 4 shows an operation flow diagram of the programmer 2. In step Sil, the disk head moves to the cylinder "No. 0" at the beginning . Then, the processing routine proceeds to step S12 where the actual programming is carried out. In step S12, an N number of access requests is read and searched from the access request buffer in the order from the previous (old) requests at the time in step S12-1. In a request for access, the number of blocks that should be accessed and the initial diiections of the data buffer used for the data transfer is described. In addition, the number N is a prima facie constant based on another control program (not illustrated). In step SI 2-2, block map 3 is referenced each of the number N of access requests, and the physical addresses of the blocks must be accessed (cylinder number, number of media, and sector numbers) are confirmed. Subsequently, in step S12-3, this number N of access requests is reset in an order from the smallest cylinder number to the largest one. Through this operation, the operation of the EXPLORE algorithm is performed. In step S12-4, this rearranged array requests are sent to the disk through the device eont-roader in the order from the smallest to the largest cylinder number and real access and data transfer are performed. When access instructions corresponding to a block are provided, the end of the transfer is expected in step S12-5, and then the new access instruction is displayed. By repeating this number N times (S12-6), processing of an N number of action requests is terminated. In step S12-7, does the control program re-e warning? that the processing of the access number N has ended, and the processing sequence related to the number N of acr requests ends. Finally, in step S12-8 it is determined if an access number N of access requests is not stored in the access request buffer 4. If this is not the case, the programmer-2 returns to step S12-3, takes the next N number of access requests, and continues the processing. If there is no N number of requests in the access request buffer, the proposal is suspended at this stage. Note that, for example, the assigner of block 1 arranges the blocks and changes the sizes of the blocks in such a way that the separation is constant in the whole area from the outside to the inner part of disk 5, so What can be improved ad t? ona Try the access property lt lempo rea 1. SECOND MODALITY Programmer 2 of the first modality explained above is raised to the most external access position at the start of the next scan. That is, when the last access was made in steps S12-4 and S12-5 in Figure 4, the head performed the most internal access between the access number N. By means of the first access of the loop for the processing of the next number N of accesses, the movement towards the external cylinder with the smaller cylinder number is caused, Frt regarding e. = >; you > In this case, a search operation of the greater length from the internal circumference towards the external circumference and a rotation delay of a rotation are generated in the worst case. Since these occur for each number N of ac ce and since the data arc can not be performed during this time, this must be added to the total sum of the load times of the total scan. And, obviously, performance decreases by that amount. Obviously it is possible to have access to the disk even during the movement from the internal circumference to the external circumference, but since the direction of movement of the head becomes inverted, the first term of equation (15) is to go, the sign of the term of the bias, is reversed. For this reason, the optimal bias and separation in the case of the movement from the external cipher to the internal circumference does not always become adequate parameters for the movement in the reverse direction. This becomes a cause of performance reduction when the head travels in the reverse direction. The apparatus for controlling access to a record disk in accordance with the second embodiment of the present invention, which will be explained below, also for this problem and provides a method for performing a high-speed data transfer even when It is possible to return from the c: J-internal tandem to I3 ac 1 rcunferenc 1 to external. First, the block allocator 1 divides the cylinders into cylinders 50 indicated by the part that is being used when it is being carried out, n3 exploration from the outside part to the internal part and the cylinders used. the internal part towards the external part as shown in figure 14. In figure 14, the cylinders 50 marked by the letters F are used when a scan is made from the external part towards the inner part, and the cylinders 50 marked by the letters B are used ita do a scan from the inside to the outside. In Figure 14, the cylinders are divided into groups of two cylinders, but the number of cylinders in a group is not limited to this. Cylinders can be divided into groups of suitable units.

In the same manner as in the apparatus for controlling access to a record disk according to the aforementioned first mode, the processing of steps S4 and S5 shown in figure 3 after finding the bias and separation in accordance with step SI of figure 3 changes bed is shown in figure 15. In figure 15, the initial step S33 picks up the pointing of the physical address to be assigned in the same way as in the first mode. Subsequently, the respective blocks are assigned to the disk in platform S32. Step 532 is a repeated loop for all blocks. In step S32-1, it is analyzed whether an entire block belongs to the regions of F or to the regions of B based on the physical di rection of the block during processing. Step S32-2 is a branch based on the result of this site. If a whole block belongs to the regions of S, steps S32- through S32-7 are carried out. In them, step 532-3 is the same as step S5-1 in Figure 3 and it is a way to examine the number of corresponding logical sectors by using the table of physical addresses, while step S32 -4 performs the writing prompt on the block map 3 in the same manner as step 55-2 in figure 3. In comparison with the block map 3 of the first embodiment presented in figure 7, in the apt of blocks 3 in the present embodiment, an indicator is added that indicates whether this block is in the regions of F or in the regions of B. This situation appears in figure 16. Step S32-5 is a step and write F in this part. When a block a belongs entirely to the regions of F ert the branch of step S32-2, the allocation to this physical di ree r ion is not made, and a physical address is sought that completely returns within the regions of F. In step S32-6, the following physical address is found from -session and separation, and it is examined ad 1 on the basis of which regions it belongs. Step S32-7 determines whether or not the internal reading has been read. If this is not the case, the processing routine jumps to step S32-1, after which the JUDGE is carried out again in step 532-2. In this way, new attempts are repeated during which a physical address is obtained for the total block qu > ? belonging to. the regione-, dt- F. This address is assigned to the block. For example, in Figure 16, e the case of system e, arrangement of the first modality, the next block no 5 was placed in the physical address (1/5/8), but the last mi of the block extends on the cylinder no. 2 for this. The cylinder does not. 2 is the regions of B, therefore regions are not assigned, and the address that may be applied later is found sequentially. The physical address pointer is successively advanced and the physical address (4/2/0) is assigned to the block no. 5. As in the case of the first modality, both in the method to assign 1 > In this way, the relationship between the distance (number of cylinders) of the radial direction and the amount of bias must be kept constant, Consequently, the assignment method is used as explained above. It is the reason why the use does not start from the front piarte (4/0/0) of the cylinder or. 4. The previous pirocesami is repeated until the physical direction reaches the extreme inner circle. Steps 533 to S36 perform a procedure. ent .. similar in laugh.-, ion to the regions of B. The beginning of the regions of B is the illicit no. 2 co or e = > In Figure 14, therefore, the one physical direction is 3 or the one in the direction in step 533, Subsequently, the sign is biased and invested in the country. of B are milked from the internal circumference to the circumference, therefore the amount of cylinder movement becomes negative. Consequently, when the sign of the bias corresponding to this is also inverted, the optimal bias for the movement of the head from the internal part to the external part is obtained. Step S35 is the step to actually write the data in the block map. This part is imilar to steps 532-1 to S32-6. Observe, however, that this - >; different from steps 532-3 through 532-7 of the ways; (3) The data-s, are written in the block map only when the whole block is in the regions of F;. Otherwise, another attempt is made for a new typical di ection. (2) B is written in the blocks apa. Finally, step S36 determines if all the blocks to be processed have been processed. If na is the case, the processing returns to step 533. If tcr > do =. the blocks to be processed have been processed, the process is defined in this step. Figure 16 shows an example of a case where 5012 blocks are -isigrtHn to regions e B in l. At this moment, the number of blocks of the regions of B starts from 5013, and the allocation of the blocks st-repeats until the head reaches again the internal circumference and emi. Since the block allocator 1 has the configuration described above, the scheduler 2 only retrieves the requests to access the regions of B from the address requests buffer to be programmed when the head is moved from the outer circumference towards the internal circumfusion direction and retrieves only the requests to access the regions of B from the address requests buffer to be scheduled when this is finished and the head moves from the internal ciunference to the outer circumference. In this way, regardless of the direction of movement of the head, the rotation delay can always be suppressed at the minimum level. In the first modality, therefore, while a delay time was caused so that the head that reached the internal ccference reaches the circumference, there is no such delay in the second current modality, in such a way that the performance of the disc is improved. It should be noted that, in the embodiment, it was mentioned that when a block was large and spread out in a plurality of tracks and rectors, the efficiency was good and another bias was provided in these times. In the present second embodiment, the use of a similar technique is possible. In the present second fashion, when the head is dislodged from the internal ircunference to the external circumference, the action is transferred to the mind from the inner third beat the external cylinder also in the accesses within a block, consequently a bias may be provided to obtain the time necessary for the cylinder movement in a direction reverse to the direction of movement from the circumference towards the internal cunference. Note that, chrome is shown in Figure 14, providing the cylinders 5 and cylinders 53 of the way that they are dispersed from the extreme internal circumference to the extreme internal circumference in the disk, the performance of disk access can be improved over time. i onally. As previously mentioned, of conformities > In the method of access control to a record disk of the present invention and to the corresponding apparatus, the time of loading the record disk, ie the sum of the search time and the rotation delay time, can be reduced. Additionably, it can be guaranteed that the maximum value) of said loading time is a value linked. In addition, it provides a bias for the control method of aer a record disk in accordance with the present invention and the corresponding apparatus, providing a bias corresponding to the direction of movement of l a. b r for each region, it is possible to reduce the charging time independently in 1A di ci n of movement of the head.

It is understood that during or after the period during which the head has access to the disc, the programming is determined for the next movement of head ac- cession. When it is possible for the access movement to start, the head is detuned to an initial position which is defined by the schedule determined for such movement of the next step of the head. In the case the first movement of > > that of the cabwza after activating the apiatato df figure 2, 33 head moves to a starting position defined by the first program ion determined after the start. While the present invention has been described with reference to the preferred embodiments, said invention is not limited to these embodiments but includes all apparent modifications to the experts in the art.

Claims

CLAIMS 1. A method for controlling access to a record disk, comprising the steps of: determining a bias that minimizes a rotation delay time to an average distance of movement when a head has access to the record disk; determine a position of a block of data in the record disk based on the lie to the determined bias; scheduling an order of a plurality of requests for access to the input disk to minimize an amount of movement of the head when the head has access to the control dial; and have access to the record disk through the head based on the result.- of the programming.
2, A method to control access to a record disk in accordance with that established in rei ication 3, where the determination of the position of the data block in the record disk is based, in addition to being based on the bias d finished, in? rt3 separation indicating an angular difference between a start and end of the same block of data.
3. A method for controlling access to a registration disk in accordance with that set forth in claim 2, further comprising the steps of: determining combination rates for each combination of bias and separation for a plurality of data blocks; and selectively using the combination data in accordance with a position of each data block on the reg- ister disk.
4. A method to control access to a record disk in accordance with that established in claim 1, where the size of the data block changes in such a way that the separation is constant throughout the region from the outside to the the internal piarte of the record disk.
5. A method for controlling access to a record disk in accordance with what is set forth in claim 3, wherein the bias is determined in accordance with a change in the ep r ra on of the data block based on a radio difference of the registration track.
6. A method for controlling access to a record disk in accordance with that set forth in claim 1, from the step of programming changes in the order of a plurality of solids to disk access in such a way that they are arranged in an order starting from the closest to the head when the head moves from the current position to one of an internal ciunference and external circumference of the record disc; and the step of determining the position of the block of data on the record disk is based on, in addition to the bias, a separation indicating an angular difference between a start and an end of the same block of data, such that a difference between a delay time Td (l) and a search time Ts (L) close to a distance The average search time becomes sufficiently small in comparison with a rotation cycle, where Td (L) = íl 4 Be. heta s + theta g + 2 m pi) / omega, and l = L t í N- 1) where, L is a search distance in units of the number of c 111 n ros; Be is a block number of data that exists in a c i 1 i nd r-o; theta s is a bias in units of radians; theta cj is a separation in units of radians; omega is a rotation speed (radian / sec) of the disk; 1.1 is a maximum value of the distance between access positions of dus we enter when arranging the access solie tudes in order in units of the number of cylinders; N is a number of accesses to be processed simul aneously; and m is selected to become the smallest within a range where Td (L) exceeds the search time Ts (L) in the search distance L.
7. A method for controlling access to a record disk in accordance with plant.eado in claim 1, wherein: the programming step changes the order of a plurality of requests for disk access in such a way that they are arranged in an order of appearance when the abeza moves from the current position towards an internal circumference and circumference;; and the step of determining the position of the data block on the record disk will be < * in, in addition to the bias, a separation in such a way that a delay time Td (L) is always greater than a search time Ts (L) and the difference between delay time Td (L) and the search time ? eda Ts (L) becomes sufficiently small compared to a rotation cycle, where Td (I) - (L »Bc. theta s + tlteta g) / omega, and where, L is a search distance ert units of the number of c 111 n ro; B is a number of blocks clc- > data that exists in a cylinder; theta s is a bias in units of radians; theta g is a separation in units of radians; and omega is a rotation speed (radian sec) of the disk.
8. A method to control the access to a record of compliance with what is stated in section 3, where: the record disk is divided into first regions for use when the head moves from the internal circumference towards Circumference and third regions will be used when the head moves from the outer circumference to the inner circle; the step of determining the position of the data block ert the record disc determines the position of the data block on the record disk based on an optimal bias and ... separation separation between the respective regions based on the direction of movement from a .-. abe-a; and the step of selectively programming accesses only to the first and second regions in accordance with the direction of motion of the start.
9. A method for controlling access to a record disk in accordance with that set forth in rei indication 8, wherein the first regions and the second regions in the record area identify the disk in a plurality of ways. two parts, along the radial direction and both the first regions and the second regions are assigned so that they are dispersed from the extreme internal circulation to the extreme circumference of the disk. 30.
An apparatus for controlling access to a record disk, which comprises a device for determining the bias to determine a bias in such a way as to minimize a rotation delay time in the average distance of movement when a head has access to the Retriever disk; a data block arrangement device for determining the position of a block of data on the disk of king i at least on the basis of which it is deter- mined; and a prain-ain device for programming an order of a plurality of requests for the -display of input discs in such a way that the amount of movement of the head becomes small at the time of access of the registration data by the head, and where the head has access to the record disk based on the results of the programming. 33.
An apparatus for controlling the 3rd or to a record disk in accordance with that set forth in claim 11, wherein the data block arrangement device determines the position of the data block based on, in addition, the bias, a separation indicating the angular difference between a mu IO and an end I of the same data block.
12. An ap > It will be possible to control access to a record disk in accordance with what is stated in rei indication 13, where the data block arrangement position determines the combination of data in relation to each combination of sescjo and separation for a plurality of data blocks and selectively fuses the combiner data in accordance with the position of each data block on the record disk.
13. An apparatus to control a < You will be able to access a record disk in accordance with the provisions of the JO reiication. where the arrangement device of data blocks changes the size of the data block of t so that the separation is constant throughout the region from the external plane to the internal part of the regi a ro disk.
14. A device for controlling the access to a record disk in accordance with the provisions of claim 30, wherein the bias correction device determines the compliance bias with the change of separation of the data block based on a radio difference of the register register.
15. An apparatus for controlling the action of a recording disk in accordance with that established in the re v i n c i-1, where; The programming device changes the order of a plurality of requests for disk access in such a way that they are arranged in an order starting from the one closest to the head when the head moves from the current position to one of "the internal circumference and circumference e? terna of the record disk; and the data block arrangement device determines the position of the data block in the record disk in Liase a, in addition to the bias, a separation indicating an angular difference between a start and an end of the same block cié datéis, of such that a difference between a given delay time Td (L) and a search time Ts (i) of an average search distance The one given by the following equation (2) becomes sufficiently small in comparison with the cycle of rotac in, where, Td (L);: (l.Pe H theta s + heta g + 2 pi) / omega íl) la = lt / (Nl) where, L is a search start in units of the number of er 111 nd ro; B is a block number of data that exists in a • r 11 mdro; theta s is a bias in units of radians; Theta g is a separation of radio units; omega is a speed of rotation radian / sec) of the disk; Lt is a maximum value of the distance between access positions of two ends when the requests are arranged and access in order in units of the number e cylinders; N is a number of accesses to process if at the end; and it is selected that it becomes as small as possible within a range where Td (L) exceeds the search time Ts (I) in the search distance L.
16. An apparatus for controlling access to a record disk of according to the provisions of claim 10, wherein: the programming device changes the order of a plurality of requests for disk access in such a way that they are arranged in the order of appearance when the head moves from the current position towards a of a data set in the internal and external circumference of the record disk and the data block arrangement device determines the position of the data block in the record disk based on, in addition to the bias, a separation such that a The delay time Td (L) provided by the following equation is always greater than the search time Ts (L) and the difference between the delay time Td íl) and the search time T ~. (L) becomes suffciently small in comparison with the rotation cycle, where, Td (L) = IL.Be "theta s + theta) / omega (1) La = L / iN-3) eionde, L is a distance search in units of number 1 i nd ro; Be is a data block number that e; istep in a cylinder; theta s is a bias in units of radians; theta g is a separation in units of radians; and omega is a rotation speed rad radian / sec) of the disk.
17. A device can control the access to a record disk in accordance with the one proposed in Chapter 3. where: the record disk! it is divided into first regions for use when the head moves from the internal circumference to the external circle and second regions for its use when the movement moves from the external circumference to the internal circum- ference; the data block arrangement device determines the position of the data block in the record disk based on an optimum bias and a separation in the respective regions, based on the direction of movement of the head; and the programming device and selectively access only the first regions and the second regions in accordance with the direction of movement of the head.
18. An apparatus for controlling access to a record disk according to Claim 17, wherein the first regions and the second regions on the record disk divide the disk ert a plurality of at least two portions along of the radial direction and both the first-, regions and second regions are assigned to what is dispersed from the extreme internal circumference to the outer extreme circumference of the disk.
19. A method to control access to a disk, comprising the. steps of: determining a position of a number of items. on the disk, to minimize a time of rotation delay at an average distance of movement each time a head has access to the dial; scheduling a tub order plurality of access requests to reduce the amount of head movement when the head has access to the disc; and have access to the disc by the head and on the basis of the result of the programming. 2 .
A method according to the provisions of the rei indication 19, wherein said step of determining a position further comprises the steps of: determining a bias in such a way as to minimize the time of rotation delay in the average distance of movement at the time of disk access by the head; determining the position of the data block on the disk based on at least the determined bias, where said bias indicates an angular difference in a circumferential direction between the start of adjacent blocks.
21. A method according to the provisions of the rei indication 20, wherein said determining step determines the position of the data block on the disk based on, in addition to the bias, a separation, said - =. Ep? A rae i ón indicates an angular difference between a start and an end of the same block of data.
22. An apparatus for controlling access to a disk, which comprises a device for determining a position of a block > .ie data on the disk to minimize a rotation delay time and an average grinding distance each time a disk has access to the disk; disposition to program an order of a number of requests for disk access to minimize an amount of head movement when the head has access to the d > -; and willing to have access to the disc by the head of the head based on the result of the programming.
23. An apparatus according to claim 22, wherein a device for determining a position further comprises: a device for determining a bias in such a manner as to minimize the rotation delay time in the average distance of movement at the moment of access of the di cro by the head; and device to determine the position of the data block in the disk based on at least the determined bias, so that said bias indicates an angular difference in a c cferential direction in the beginning of blocks adjacent s.
24. An apparatus of compliance with the provisions of claim 23, where said device for determining determines the position of the data block on the disk based on, in addition to the bias, an awareness, said separation indicates an angular difference between? n start an end of the same block of .Jatos.
25. An apparatus for controlling access to a register, comprising: a device for determining bias to determine a bias in such a way that ._ >It minimizes a time of retreat, a citation of the average distance of movement when a head has a record disk; ? ri assigned from block to determine the position of a block of data on the record disk based on at least the determined bias; and a programmer! an order of a plurality of disk access requests entered in such a manner that the amount of movement of the head becomes small at the time of access of the record disk by part of the head, and where the head has access to the head; record disk based on the results of the programming.
26. An apparatus for controlling access to a record disc in accordance with that set forth in the indication 25, where the allocator determines the position of the data block based on, in addition to the bias, a separation indicating the difference - Ang angle between a start and a row of the same data block.
27. A device for controlling access to a record disk in accordance with claim 26, wherein the block allocator determines the character of the dator. in relation to each combination of bias and separation for a plurality of-? data blocks and selectively uses the combination data according to the onion of the data block in the data of 1 ec tur.
28. An apparatus for controlling the access to a record disk in accordance with that set forth in claim 25, wherein the block node changes the size of the data block so that the separation is constant throughout the region from the external part towards the internal pair of the record disc.
29. An apparatus for controlling access to a record disk in accordance with that set forth in claim 25, wherein the device to determine the bias determines the compliance bias with a change of separation of the data block based on a difference of radio track of re ist va.
30. An apparatus for controlling access to a record disk in accordance with that set forth in claim 25, wherein: the programmer- changes the order of a plurality of disk access requests in such a manner as to be arranged ert an order starting a paiti from the one closest to the head when the head is moved from the current position to one of an internal circumference and external circumference of the registration head; and the block identifier determines the position of the data block, in the registration disk ert base a, in addition to the bias, a separation that indicates an angular difference between a start and a same block of data, of so that a difference between a given delay time Td (L) and a search time Ts (1.) near an average search distance The one given by the following equation (2) becomes sufficiently small in comparison with the rotation cycle, where, Td (L) = L. Be, heta s + theta g + 2 pi) / omega (1) La = Lt / (N-1) (2) where, L is a search distance in units of the number of c 111 nd ros; Be is a block number of data «that exist in a c 111 nd ro; theta s is a ses.ge > units of radians; theta g is a separator in units of radians; omega is a rotation speed (radian / ^ ec) of the disk; Lt is a value plus i or the distance between access positions of do = enter when the requests for ac are arranged in order in uni dictes of the number of cases; N is a number of accesses simultaneously; and it is selected so that it becomes as small as possible in a range where Tdl.) exceeds the search time Ts (L) in the search distance L.
31. A computer can control access to a record disk in accordance with what is stated in claim 25, where: the programmed? - changes the order of a plurality of requests for access to disk in such a way that they are subject to the order of appearing when the head is discarded from the current position becomes one of internal circumference and the external register of the record; and the block allocator determines the position of the data block on the record disk based on, in addition to the bias, a separation such that a delay time Td d.) provided by the following equation is always greater than the search time Ts (L) and the difference between the delay time T (L> and the search time Ts (I.) becomes sufficiently small in comparison with the broken cycle »ion, where, Tcl íL) - (L. Be. «Theta s + theta) / omega and where, l. is a search distance in units of the number of er i 1 indros; Be is a data block number that is-istert in a c i 11 ndro; theta s is a bias in units and radians; theta g is a separation in units of radians; and omega is a rotation speed (radian / sec) of the disk;
32. An apparatus for controlling access to a registration disk of identity with that set forth in claim 2, wherein: the record disk is divided into first regions for use when the head is moved from the internal circumference towards the outer circumference and second regions for its use when it is possible to move from the external circumference to the internal circumference; the block allocator * determines the position of the data block on the record disk based on an optimum bias and a separation in the respective regions based on the direction of movement of the head; and the programmer and access only to the first and second regions of conformity in the direction of movement of the cabinet.
33. An appliance for >; or controlling access to a record of registration in accordance with that set forth in claim 32, on the first-; regions and the second regions in the disk. The record divides the disk into a plurality of at least two parts along the radial direction and both the first regions and the second regions are allocated in such a way that ^ tert di sp? er - =. a =. from- »the inner circle rtferertc the e t row towards the outer circumference e: row in the i se.