摘要:
A data transfer apparatus for use with a replaceable disklike record medium such as a flexible magnetic disk having data storage tracks thereon, comprising a disk drive motor for imparting rotation to the record medium, and a head transport motor for transporting a transducer head or heads radially of the record medium so as to enable the transducer head or heads to access the individual data storage tracks on the record medium for data transfer therewith. Also included is a control and drive circuit for controllably energizing the head transport motor. When the disk drive motor is out of rotation, the control and drive circuit holds the supply voltage of the head transport motor zero, or lower than its normal operating voltage for head transportation, for saving power. Then, as the disk drive motor is set into rotation, the control and drive circuit applies the normal operating voltage to the head transport motor preparatory to the commencement of data transfer, thereby automatically recorrecting the head position on the record medium.
摘要:
An electric control system for an apparatus for writing and reading data on and from a flexible magnetic disk under the control of host equipment such as a central processor unit having an associated controller. The control system includes a time setting circuit responsive to stepping pulses, by which the magnetic head is transported from track to track on the disk, for determining an access time to be elapsed from the moment the head starts to be transported from any track on the disk to any other track thereon to the moment the head becomes stably positioned on the new track. Connected to the time setting circuit is an index pulse suppressor circuit which suppresses any index pulse, indicative of the rotation and angular position of the magnetic disk, that is generated during each access time and which permits the delivery to the host equipment of the subsequent index pulses that are generated after the lapse of the access time. A read data suppressor circuit is also provided which inhibits the delivery to the host equipment of any data read from the disk either during the access time or from the moment the transducer head starts moving toward a new track to the moment the first index pulse is generated after the lapse of the access time. Thus the host equipment is conditioned to commence the writing of data only after the head is stably positioned on each new track.
摘要:
Several data storage devices for use with flexible magnetic disks are daisy chained to a central processing unit via a controller to be selectively driven thereby for data transfer with the magnetic disks. Each storage device has a motor control circuit for setting the magnetic disk into rotation when a corresponding DRIVE SELECT signal from the controller assumes a prescribed state for the first time after and IN USE signal common to all the storage devices has assumed a prescribed state. Further the motor control circuits sets the magnetic disk out of rotation when the DRIVE SELECT signal assumes the prescribed state for the first time after the IN USE signal has been set out of the prescribed state. Thus the storage devices are held out of operation to avoid unnecessary power consumption even after the production of the IN USE signal, until the associated DRIVE SELECT signals are applied. Moreover, once set into operation, the storage devices remain so despite changes in the states of the DRIVE SELECT signals during the production of the IN USE signal, allowing ready access for data transfer.
摘要:
A microcomputer system having a flexible magnetic disk drive and a controller therefor, with the disk drive including a stepper motor for incrementally moving a transducer from track to track on a rotating magnetic disk, and a clock which is inherently unstable in operation during a predefinable startup period thereof after being powered on. In order to enable the disk drive to internally generate stepping pulses for driving the stepper motor at twice as high a rate as by external stepping pulses from the controller without being affected by unstable clock pulses during the startup period of the clock, the controller supplies external stepping pulses to the disk drive after imparting a predetermined delay, longer than the startup period of the clock, to each series of external stepping pulses with respect to the moment a power save signal, also supplied from the controller to the disk drive, indicates that the clock and other power consuming parts of the disk drive be powered. Within the disk drive a counter counts the clock pulses for a length of time equal to half the period of each series of external stepping pulses in response to each incoming external stepping pulse, thereby providing output pulses that rise with the respective external stepping pulses. A pulse generator circuit generates internal stepping pulses in synchronism with both leading and trailing edges of the counter output pulses. Additional embodiments are disclosed.
摘要:
A mold for manufacturing a skin covered foamed plastic article incorporating a hole, with which it is possible to place the skin cover at a desired position despite of the presence of the hole, without spoiling or damaging the skin cover, such that the skin covered foamed plastic article of a desired shape without any deficiencies such as wrinkles and dents can easily be manufactured. The mold includes a lower mold having a cylindrical bossing with a hollow inside, corresponding to the hole, around which the skin cover is placed in such a manner that an edge of a hole on the skin cover is located in the hollow inside the cylindrical bossing, the cylindrical bossing being in such a shape that the hollow inside the cylindrical bossing is shielded off from the cavity when the lower mold is assembled with the upper mold so that the liquid foam resin cannot enter into the hollow; and a fastening cap, to be attached to the cylindrical bossing over the skin cover, for fastening the skin cover to the cylindrical bossing at a desired position.
摘要:
A mold for manufacturing a skin covered foamed plastic seat capable of effectively dealing with the variations in shape and position of the trim ends. The mold includes stopper means for fastening the trim ends attached to the edges of the skin cover, located between the upper mold and lower mold separately from a space into which a liquid foam resin is to be poured, each of the stopper means having a slit through which one trim end is inserted, and a top face portion to which both ends of the trim end are to be hooked.
摘要:
A control system for a disk drive operating under the control of a host system for data transfer with a magnetic disk medium. The host system provides a signal indicative of whether the disk drive is in operation in a read-only mode or in a write-only or read-and-write mode. During operation in the write-only and read-and-write modes, the control system inhibits the delivery to the host system of both read data and index pulses during, for example, a disk start-up time, and access time and a transducer loading time, because the data recovered from the disk medium during such times may be inaccurate, inviting inaccurate writing. However, during operation in the read-only mode, the control system constantly permits the delivery of read data and index pulses to the host system with a view to the curtailment of the average read access time.
摘要:
A double capacity adapter circuit is connected between host equipment and one or more magnetic disk drives in order to adapt the host equipment, which has been programmed for use with relatively small capacity magnetic disks, for use with double capacity magnetic disks in the disk drives coupled thereto. As originally programmed, the host equipment formats one side of a small capacity magnetic disk with first format data in response to an index pulse from the associated disk drive, and the other side of the small capacity magnetic disk with second format data in response to another index pulse. In order to format the double capacity magnetic disks with the same program, the adapter circuit delays the index pulses by a time corresponding to half a revolution of the magnetic disk, thereby producing pseudo index pulses. The adapter circuit further enables the host equipment to cause each double capacity magnetic disk drive to write the first format data on a first half of one side of the double capacity magnetic disk in response to one true index pulse, and the second format data on a second half of the same side in response to one pseudo index pulse. Thus, for example, the complete format data that have been programmed to be written on four double sided small capacity disks can be written on two double sided double capacity disks.
摘要:
An apparatus for data transfer with a magnetic disk having a metal made hub attached centrally thereto, with the hub having a first opening defined centrally therein and a second opening defined eccentrically therein. The apparatus includes a turntable mounted on a drive spindle which is engageable in the first opening in the hub of the magnetic disk loaded on the turntable. A retractable drive pin is mounted eccentrically on the turntable so as to be sprung into engagement in the second opening in the disk hub upon register therewith. In order to assure engagement of the drive pin in the second opening in the disk hub immediately upon loading of the magnetic disk on the turntable, a disk drive motor for driving the turntable via the drive spindle is connected to a supply terminal via a power control switch. When the magnetic disk is loaded on the turntable while power is being supplied from the supply terminal, a switch control circuit closes the power control switch, for causing the rotation of the turntable relative to the magnetic disk, for a preassigned length of time sufficient for the drive pin to become engaged in the second opening in the disk hub. The magnetic disk can therefore be set into rotation for immediate commencement of data transfer upon delivery of a "motor on" signal from host equipment to the power control switch.
摘要:
A storage file for particular use with a flexible magnetic disk having a series of concentric magnetic tracks thereon, comprising a four phase stepping motor for moving a transducer head radially of the magnetic disk. The stepping motor has several sets of first, second, third and fourth phase windings arranged sequentially in the order named. A radial drive control circuit is provided which normally acts to cause energization of the stepping motor windings in a single phase drive mode to cause rotation of the rotor by discrete increments. In order to prevent the rotor from being trapped in alignment with the third phase windings, instead of being returned to the first phase windings, when the disk file is electrically turned on, the radial drive control circuit further functions to briefly energize a selected one or more of the second, third and fourth phase windings of each set, with the simultaneous or subsequent energization of the first phase windings. This makes it possible to positively return the transducer head to the outermost track zero position on the magnetic disk, for the commencement of proper data transfer therebetween, despite the unavoidable sensing errors of an optical "track zero" sensor commonly built into the device.