# US 5,349,479 A · Data transfer method of magnetic recording/reproducing apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,479 A - Document ID: US5349479A - Status: Granted - Kind: A - Application number: 08/210,103 - Filed: 1994-03-16 - Granted: 1994-09-20 - Earliest claimed: 1991-02-20 - Assignees: Alps Electric Co., Ltd. - Inventors: Noriji Arimura; Tatsumaro Yamashita - Web page: https://patentgrep.com/patent/US5349479A ## CPC - G06F 3/0601: {Interfaces specially adapted for storage systems} - G11B 15/1875: {adaptations for special effects or editing (signal processing or indexing therefor G11B27/00)} - G11B 20/10: Digital recording or reproducing - G11B 31/00: Arrangements for the associated working of recording or reproducing apparatus with related apparatus (with cameras or projectors G03B31/00 {; recording/reproducing of music for electrophonic musical instruments G10H1/0033; automatic arrangements for answering calls or for recording messages for absent subscribers H04M1/64; telephonic communication systems adapted for combination with dictation recording and playback systems H04M11/10; connection of TV recorder with other related apparatus, e.g. TV camera or receiver, in which the TV signal is significantly involved H04N, e.g. H04N23/00, H04N5/765; combination of radio or TV with other apparatus, e.g. with vehicles H05K11/00}) - G06F 3/0682: {Tape device} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract A data transfer method of a magnetic recording/reproducing apparatus which makes it unnecessary to repeatedly stop and start a recording operation or a reproducing operation in spite of changes in transfer interval and density of data transmitted between a host computer and the magnetic recording/reproducing apparatus, and which shortens the waiting time of the host computer to a minimum. When data transferred from a host computer is stored in a buffer memory and then transmitted to a rotary head, the number of revolutions of the rotary head and the feeding speed of a magnetic tape are changed by a switch control portion based on the amount of data stored in the buffer memory and the rate at which the amount of data increases or decreases. It is thereby possible to perform continuous recording regardless of the amount and density of the transferred data. When data is reproduced from the magnetic tape by the rotary head and transferred to the host computer, the number of revolutions of the rotary head and the feeding speed of a magnetic tape are also changed based on the amount of data stored in the buffer memory and the rate at which the amount of data is increasing or decreasing. ## Claims ### Claim 1 A method of transferring data to a magnetic tape recording/reproducing apparatus, the apparatus including a buffer memory for storing data and a read/write head mounted on a rotating drum for writing data from the buffer memory onto the magnetic tape, the read/write head being rotated by the rotating drum at a head rotating speed, the magnetic tape being driven over the rotating drum at a tape driving speed, the method comprising the steps of: determining an amount of data stored in the buffer memory; determining a rate at which the amount of data stored in the buffer is increasing or decreasing; and changing a rate at which data is written on the magnetic tape by selecting between a plurality of predetermined head rotating speeds and tape driving speeds in response to the determined amount of data and the determined rate of storage. ### Claim 2 (depends on 1) The method of claim 1 wherein the magnetic tape recording/reproducing apparatus includes a plurality of frequency dividers connected in series to an oscillator, each of the frequency dividers receiving an input frequency from one of the oscillator or a previous frequency divider, and generating an output frequency which is one-half of the input frequency; wherein the step of changing the rate at which data is written on the magnetic tape comprises selecting the output frequency generated by one of the frequency dividers. ### Claim 3 A method of transferring data from a magnetic tape recording/reproducing apparatus, the magnetic tape apparatus including a buffer memory for storing data and a read/write head mounted on a rotating drum for writing data from the buffer memory onto the magnetic tape, the read/write head being rotated by the rotating drum at a head rotating speed, the magnetic tape being driven over the rotating drum at a tape driving speed, the apparatus further including a plurality of frequency dividers connected in series to an oscillator, each of the frequency dividers receiving an input frequency from one of the oscillator or a previous frequency divider, and generating an output frequency which is one-half of the input frequency, the method comprising the steps of: determining an amount of data stored in the buffer memory; determining a rate at which the amount of data stored in the buffer is increasing or decreasing; and changing a rate at which the data is reproduced from the magnetic tape by selecting between a plurality of predetermined head rotating speeds and tape driving speeds in response to the determined amount of data and the determined rate of storage; wherein the step of changing the rate at which data is reproduced from the magnetic tape comprises selecting the output frequency generated by one of the frequency dividers.