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WD1770
The FD1771, sometimes WD1771, is the first in a line of floppy disk controllers produced by Western Digital. It uses single density FM encoding introduced in the IBM 3740. It is packaged in a 40-pin DIP."The FD1771 is a single-chip floppy disk formatter/controller that interfaces with most available disk drives and virtually all types of computers." The FD1771 was announced on July 19, 1976, and sold for $60 each in lots of 100. Later models in the series added support for MFM encoding and increasingly added onboard circuitry that formerly had to be implemented in external components. Originally packaged as 40-pin dual in-line package (DIP) format, later models moved to a 28-pin format that further lowered implementation costs. Derivatives The FD1771 was succeeded by many derivatives that were mostly software-compatible: *The FD1781 was designed for double density, but required external modulation and demodulation circuitry, so it could support MFM, M2FM, GCR or other dou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commodore 1581
The Commodore 1581 is a 3½-inch double-sided double-density floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ... drive that was released by Commodore International, Commodore Business Machines (CBM) in 1987, primarily for its Commodore 64, C64 and Commodore 128, C128 home computer, home/personal computers. The drive stores 800 kilobytes using an Modified Frequency Modulation, MFM encoding but formats different from the MS-DOS (720 kB), Amiga (880 kB), and Macintosh Plus, Mac Plus (800 kB) formats. With special software it's possible to read C1581 disks on an x86 PC system, and likewise, read MS-DOS and other formats of disks in the C1581 (using Big Blue Reader), provided that the PC or other floppy handles the size format. This capability was most frequently used to re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acorn Electron
The Acorn Electron (nicknamed the Elk inside Acorn and beyond) was a lower-cost alternative to the BBC Micro educational/ home computer, also developed by Acorn Computers Ltd, to provide many of the features of that more expensive machine at a price more competitive with that of the ZX Spectrum. It had 32 kilobytes of RAM, and its ROM included BBC BASIC II together with the operating system. Announced in 1982 for a possible release the same year, it was eventually introduced on 25 August 1983 priced at £199. The Electron was able to save and load programs onto audio cassette via a supplied cable that connected it to any standard tape recorder that had the correct sockets. It was capable of bitmapped graphics, and could use either a television set, a colour (RGB) monitor or a monochrome monitor as its display. Several expansions were made available to provide many of the capabilities omitted from the BBC Micro. Acorn introduced a general-purpose expansion unit, the Plus 1, off ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commodore 1571
The Commodore 1571 is Commodore's high-end 5¼" floppy disk drive, announced in the summer of 1985. With its double-sided drive mechanism, it has the ability to use double-sided, double-density (DS/DD) floppy disks, storing a total of 360 kB per floppy. It also implemented a "burst mode" that doubled transfer speeds, helping address the very slow performance of previous Commodore drives. Earlier Commodore drives used a custom group coded recording format that stored 170 kB per side of a disk. This made it fairly competitive in terms of storage, but limited it to only reading and writing disks from other Commodore machines. The 1571 was designed to partner with the new Commodore 128 (C128), which introduced support for CP/M. Adding double-density MFM encoding allowed the drive to read and write contemporary CP/M disks (and many others). In contrast to its single-sided predecessors, the 1541 and the briefly-available 1570, the 1571 can use both sides of the disk a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BBC Master
The BBC Master is a home computer released by Acorn Computers in early 1986. It was designed and built for the BBC, British Broadcasting Corporation (BBC) and was the successor to the BBC Micro, BBC Micro Model B. The Master 128 remained in production until 1993. Design The Master series featured several improvements on preceding BBC Micro models. The systems had RAM as standard, alleviating the shortage of available RAM which had amongst other things discouraged use of the best graphics modes in the original design. The Master 128 and its variants had two cartridge slots mounted behind the new numerical keypad, these employing sockets that provided a superset of the Acorn Electron Acorn Electron#Acorn Plus 1, Plus 1 cartridge interface capabilities, supporting the use of physically compatible Electron cartridges, but also supporting enhanced electrical characteristics for some of the cartridge connector pins. Rather than the MOS Technology 6502 Central processing unit, micropro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FD1771 FDC Datasheet
The FD1771, sometimes WD1771, is the first in a line of floppy disk controllers produced by Western Digital. It uses single density FM encoding introduced in the IBM 3740. It is packaged in a 40-pin DIP."The FD1771 is a single-chip floppy disk formatter/controller that interfaces with most available disk drives and virtually all types of computers." The FD1771 was announced on July 19, 1976, and sold for $60 each in lots of 100. Later models in the series added support for MFM encoding and increasingly added onboard circuitry that formerly had to be implemented in external components. Originally packaged as 40-pin dual in-line package (DIP) format, later models moved to a 28-pin format that further lowered implementation costs. Derivatives The FD1771 was succeeded by many derivatives that were mostly software-compatible: *The FD1781 was designed for double density, but required external modulation and demodulation circuitry, so it could support MFM, M2FM, GCR or other dou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Modulation Encoding
Frequency modulation encoding, or simply FM, is a method of storing data that saw widespread use in early floppy disk drives and hard disk drives. The data is modified using differential Manchester encoding when written to allow clock recovery to address timing effects known as "jitter" seen on disk media. It was introduced on IBM mainframe drives and was almost universal among early minicomputer and microcomputer floppies. In the case of floppies, FM encoding allowed about 80 kB of data to be stored on a -inch disk. IBM began introducing the more efficient modified frequency modulation, or MFM, starting in 1970. They referred to this format as "double density", with the original FM retroactively becoming "single density". MFM was more difficult to implement and it was not until the early 1980s that low-cost all-in-one MFM floppy drive controllers like the WD1770 emerged. This led to the rapid demise of FM encoding in favor of MFM by the mid-1980s. Underlying storage m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM 3740
IBM 3740 Data Entry System was a data entry system that was announced by IBM in 1973. It recorded data on an 8" diskette, a new recording medium from IBM, for fast, flexible, efficient data entry to either high-production, centralized operations or to decentralized, remote operations. The "Diskette" was more commonly known as an 8-inch floppy disk. History The system was announced in January, 1973; became available in the second quarter of that year; and was withdrawn from marketing in December, 1983. It was developed by IBM's General Systems Division facility in Rochester, Minnesota. The IBM 3740 system was intended to replace the traditional unit record equipment, using the IBM card. Configuration The IBM 3740 system consisted of the following equipment: (IEEE Computer Societ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fujitsu
is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the largest in Japan, in 2021. The hardware offerings from Fujitsu are mainly of personal and enterprise computing products, including x86, SPARC and mainframe compatible server products, although the corporation and its subsidiaries also offer a diversity of products and services in the areas of data storage, telecommunications, advanced microelectronics, and air conditioning. It has approximately 126,400 employees and its products and services are available in approximately 180 countries. Fujitsu is listed on the Tokyo Stock Exchange and Nagoya Stock Exchange; its Tokyo listing is a constituent of the Nikkei 225 and TOPIX 100 indices. History 1935 to 2000 Fujitsu was established on June 20, 1935, which makes it one of the oldest operating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Digital
Western Digital Corporation (WDC, commonly known as Western Digital or WD) is an American computer drive manufacturer and data storage company, headquartered in San Jose, California. It designs, manufactures and sells data technology products, including data storage devices, data center systems and cloud storage service A file-hosting service, cloud-storage service, online file-storage provider, or cyberlocker is an internet hosting service specifically designed to host user files. It allows users to upload files that could be accessed over the internet afte ...s. Western Digital has a long history in the electronics industry as an integrated circuit maker and a storage products company. It is one of the largest computer hard disk drive manufacturers, along with producing solid state drives and flash memory devices. Its competitors include the data management and storage companies Seagate Technology and Micron Technology. History 1970s Western Digital was founded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinclair ZX Spectrum
The ZX Spectrum () is an 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer. Referred to during development as the ''ZX81 Colour'' and ''ZX82'', it was launched as the ''ZX Spectrum'' to highlight the machine's colour display, which differed from the black and white display of its predecessor, the ZX81. The Spectrum was released as six different models, ranging from the entry level with 16 KB RAM released in 1982 to the ZX Spectrum +3 with 128 KB RAM and built in floppy disk drive in 1987; altogether they sold over 5 million units worldwide (not counting unofficial clones). The Spectrum was among the first home computers in the United Kingdom aimed at a mainstream audience, and it thus had similar significance to the Commodore 64 in the US and the Thomson MO5 in France. The introduction of the ZX Spectrum led to a boom in companies producing software an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DISCiPLE
A disciple is a follower and student of a mentor, teacher, or other figure. It can refer to: Religion * Disciple (Christianity), a student of Jesus Christ * Twelve Apostles of Jesus, sometimes called the Twelve Disciples * Seventy disciples in the Gospel of Luke * Christian Church (Disciples of Christ), a Protestant denomination in North America descended from the Campbell movement * Disciples of Christ (Campbell Movement), a Christian group that arose during the Second Great Awakening * Disciples of `Abdu'l-Bahá, 19 Western Bahá'ís * The ten principal disciples of Buddha * Disciples of Confucius * Disciples of Jesus in Islam * Student of Kriya Yoga, of direct lineage to Mahavatar Babaji * Sahabah, the disciples of Muhammad * Follower of Paramahansa Yogananda * Śishya, the disciple in the Guru–shishya tradition of Hinduism * ''Śrāvaka'' (Sanskrit) or ''savaka'' (Pali), disciples in Buddhism and Jainism * Tarmida ('disciple'), a junior priest in Mandaeism Books, games, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAM Coupé
Sam, SAM or variants may refer to: Places * Sam, Benin * Sam, Boulkiemdé, Burkina Faso * Sam, Bourzanga, Burkina Faso * Sam, Kongoussi, Burkina Faso * Sam, Iran * Sam, Teton County, Idaho, United States, a populated place People and fictional characters * Sam (given name), a list of people and fictional characters with the given name or nickname * Sam (surname), a list of people with the surname ** Cen (surname) (岑), romanized "Sam" in Cantonese ** Shen (surname) (沈), often romanized "Sam" in Cantonese and other languages Religious or legendary figures * Sam (Book of Mormon), elder brother of Nephi * Sām, a Persian mythical folk hero * Sam Ziwa, an uthra (angel or celestial being) in Mandaeism Animals * Sam (army dog) (died 2000) * Sam (horse) (b 1815), British Thoroughbred * Sam (koala) (died 2009), rescued after 2009 bush fires in Victoria, Australia * Sam (orangutan), in the movie ''Dunston Checks In'' * Sam (ugly dog) (1990–2005), voted the world's ugliest dog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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