公开(公告)号：JPH03134732A

公开(公告)日：1991-06-07

申请号：JP26798689

申请日：1989-10-17

Applicant: IBM

Inventor： NUMATA TSUTOMU ,  OGAKI KAZUTAKA ,  YAMAGUCHI MARIO

IPC: G06F5/14 ,  G06F5/10

Abstract: PURPOSE: To improve the utilization efficiency of a buffer by writing data in an area where the data are not stored regardless of the size relation of the value of a write pointer and the value of a read pointer. CONSTITUTION: The write pointer for specifying a write address and the read pointer for specifying a read address are provided and the value of the write pointer and the value of the read pointer are compared at all times in a comparator 5. Then, when the value of the write pointer and the value of the read pointer match, a pointer which caught up later is discriminated by a discrimination circuit 6 and an auxiliary discrimination circuit 13, write to the buffer is inhibited at the time of discriminating that the write pointers caught up later and read from the buffer is inhibited at the time of discriminating that the read pointer caught up later inversely. Thus, the buffer is effectively utilized.

公开(公告)号：JPH0384767A

公开(公告)日：1991-04-10

申请号：JP21619889

申请日：1989-08-24

Applicant: IBM

Inventor： NAKAGAWA YOSHIHIRO ,  NUMATA TSUTOMU ,  OGAKI KAZUTAKA

IPC: G06F3/06 ,  G11B5/596 ,  G11B27/10

Abstract: PURPOSE: To shorten a track changeover time and to reduce a processor load by providing a head position control means by which a final sector indication means completes an access of a head to a detected track, according to the final sector detection signal. CONSTITUTION: A final sector of each track on a disk is provided with a final sector indication means. In a device which performs positioning control of a head 6 onto a disk 2 under a control of a processor 10 like, for example, a mask processor, the processor 10 can complete an access of the head 6 to a track of which a final sector has been detected, by inputting the detected signal for the final sector indication means to the processor 10 as an interrupt signal. Also, it can make the head 6 move to the next target track. Consequently, when reading or writing is performed over multiple tracks, a track changeover time can be shorten and, as a result, a processor load can be reduced.

公开(公告)号：JPH02158824A

公开(公告)日：1990-06-19

申请号：JP31204088

申请日：1988-12-12

Applicant: IBM JAPAN

Inventor： NAKAMURA TAKASHI ,  NUMATA TSUTOMU ,  OGAKI KAZUTAKA

IPC: G06F3/06

Abstract: PURPOSE:To effectively use the memory of a disk device by providing a shared storing means to write outputted data in conformity to prescribed preferential order and time division multiplex controlling means to read the stored data in conformity to the prescribed preferential order. CONSTITUTION:One storing means 10 is shared by a microprocessor 6, host computer 4 and the disk device 12, and the data to be outputted from the microprocessor 6, the host computer 4 and the disk device 12 is written in the shared storing means 10 in conformity to the prescribed preferential order. Then, the time division multiplex controlling means 8 to read the data stored in the shared storing means 10 to the microprocessor 6, the host computer 4 and the disk device 12 in conformity to the prescribed preferential order is provided. Namely, a memory function to store the data to be used by the microprocessor 6 to control the disk device 12 and the function to transfer the data between the disk device 12 and the host computer 4 are given to one storing means 10. Thus, the memory of the disk device 12 can be used effectively.