|
Floppy Disk Controller
A floppy-disk controller (FDC) is a hardware component that directs and controls reading from and writing to a computer's floppy disk drive (FDD). It has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit (IC or "chip") or a component thereof. An FDC is responsible for reading data presented from the host computer and converting it to the drive's on-disk format using one of a number of encoding schemes, like FM encoding (single density) or MFM encoding (double density), and reading those formats and returning it to its original binary values. Depending on the platform, data transfers between the controller and host computer would be controlled by the computer's own microprocessor, or an inexpensive dedicated microprocessor like the MOS 6507 or Zilog Z80. Early controllers required additional circuitry to perform specific tasks like providing clock signals and setting various options. Later designs included more of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM PC Original 5
International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is a publicly traded company and one of the 30 companies in the Dow Jones Industrial Average. IBM is the largest industrial research organization in the world, with 19 research facilities across a dozen countries; for 29 consecutive years, from 1993 to 2021, it held the record for most annual U.S. patents generated by a business. IBM was founded in 1911 as the Computing-Tabulating-Recording Company (CTR), a holding company of manufacturers of record-keeping and measuring systems. It was renamed "International Business Machines" in 1924 and soon became the leading manufacturer of punch-card tabulating systems. During the 1960s and 1970s, the IBM mainframe, exemplified by the System/360 and its successors, was the world's dominant computing platform, with the company p ... [...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. It was succeeded in 1980 by the IBM 5280 which added full programmability. The term "IBM 3740" is sometimes used metonymically to refer to the floppy disk recording format it introduced, which was the direct ancestor of the IBM PC floppy format which would become the industry standard in the 1980s and 1990s. 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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Frequency Modulation
In telecommunications, a line code is a pattern of voltage, current, or photons used to represent digital data transmitted down a communication channel or written to a storage medium. This repertoire of signals is usually called a constrained code in data storage systems. Some signals are more prone to error than others as the physics of the communication channel or storage medium constrains the repertoire of signals that can be used reliably. Common line encodings are unipolar, polar, bipolar, and Manchester code. Transmission and storage After line coding, the signal is put through a physical communication channel, either a transmission medium or data storage medium.Karl Paulsen"Coding for Magnetic Storage Mediums".2007. The most common physical channels are: * the line-coded signal can directly be put on a transmission line, in the form of variations of the voltage or current (often using differential signaling). * the line-coded signal (the ''baseband signal'') under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Recovery
Clock recovery is a process in serial communication used to extract timing information from a stream of serial data being sent in order to accurately determine payload sequence without separate clock information. It is widely used in data communications; the similar concept used in analog systems like color television is known as carrier recovery. Basic concept In serial communication data is normally transmitted and received as a series of pulses with well-defined timing constraints. In asynchronous serial communication this presents a problem for the receiving side: if their own clock is not precisely synchronized with the transmitter, they may sample the signal at the wrong time and thereby decode the signal incorrectly. Partially, the problem may be addressed with extremely accurate and stable clocks, like atomic clocks, but these are expensive and complex. More common low-cost clock systems, like quartz oscillators, are accurate enough for this task over short periods of ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clock Signal
In electronics and especially synchronous digital circuits, a clock signal (historically also known as ''logic beat'') is an electronic logic signal (voltage or current) which oscillates between a high and a low state at a constant frequency and is used like a metronome to synchronize actions of digital circuits. In a synchronous logic circuit, the most common type of digital circuit, the clock signal is applied to all storage devices, flip-flops and latches, and causes them all to change state simultaneously, preventing race conditions. A clock signal is produced by an electronic oscillator called a clock generator. The most common clock signal is in the form of a square wave with a 50% duty cycle. Circuits using the clock signal for synchronization may become active at either the rising edge, falling edge, or, in the case of double data rate, both in the rising and in the falling edges of the clock cycle. Digital circuits Most integrated circuits (ICs) of suffi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drive Head
Drive or The Drive may refer to: Motoring * Driving, the act of controlling a vehicle * Road trip, a journey on roads Roadways Roadways called "drives" may include: * Driveway, a private road for local access to structures, abbreviated "drive" * Road, an identifiable thoroughfare, route, way, or path between two places Science * Drive theory, a diverse set of motivational theories in psychology * Drive reduction theory (learning theory), a theory of learning and motivation * Prey drive, in the study of animal behavior, the predictable tendency of a carnivore to pursue and capture prey * Gene drive, in genetics, a type of bias in the inheritance of a gene Arts, entertainment, and media Films * ''Drive'' (1997 film), an action film starring Mark Dacascos * ''Drive'', a 2002 Japanese film starring Ren Osugi * ''Drive'' (2011 film), an American crime drama film starring Ryan Gosling * ''Drive'' (2019 film), an Indian romantic drama film * ''Drive'' (2024 film), a South K ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southbridge (computing)
In computing, a southbridge is a component of a traditional two-part chipset architecture on motherboards, historically used in personal computers. It works alongside the northbridge to manage communications between the central processing unit (CPU) and lower-speed peripheral interfaces. The northbridge typically handled high-speed connections such as RAM and GPU interfaces, while the southbridge managed lower-speed functions. The southbridge controls a range of input/output (I/O) functions, including USB, audio, firmware (e.g., BIOS or UEFI), storage interfaces such as SATA, NVMe, and legacy PATA, as well as buses like PCI, LPC, and SPI. Southbridge and northbridge components were often designed to work in pairs, though there was no universal standard for interoperability. In the 1990s and early 2000s, they commonly communicated via the PCI bus; more recent chipsets use Direct Media Interface (Intel) or PCI Express (AMD). Intel referred to its southbridge as the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super I/O
Super I/O (sometimes Multi-IO) is a class of I/O controller integrated circuits that began to be used on personal computer motherboards in the late 1980s, originally as add-in cards, later embedded on the motherboards. A super I/O chip combines interfaces for a variety of low-bandwidth devices. Now it is mostly merged with EC. Functions The functions below are usually provided by the super I/O if they are on the motherboard: * A floppy-disk controller * An IEEE 1284-compatible parallel port (commonly used for printers) * One or more 16C550-compatible serial port UARTs * Keyboard controller for PS/2 keyboard and/or mouse Most Super I/O chips include some additional low-speed devices, such as: * Temperature, voltage, and fan speed interface * Connect temperature and voltage sensors via SMBus * Thermal Zone * Chassis intrusion detection * Mainboard power management, including control voltage regulator module * LED management * PWM fan speed control * An IrDA Port cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM Personal Computer
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on August 12, 1981, it was created by a team of engineers and designers at International Business Machines (IBM), directed by William C. Lowe and Philip Don Estridge in Boca Raton, Florida. Powered by an x86-architecture Intel 8088 processor, the machine was based on open architecture and third-party peripherals. Over time, expansion cards and software technology increased to support it. The PC had a substantial influence on the personal computer market; the specifications of the IBM PC became one of the most popular computer design standards in the world. The only significant competition it faced from a non-compatible platform throughout the 1980s was from Apple's Macintosh product line, as well as consumer-grade platforms created by companies like Commodore and Atari. Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Digital FD1771
The FD1771, sometimes WD1771, is a floppy disk controller chip, the first in a line of floppy disk controllers produced by Western Digital. It uses single density FM encoding introduced in the IBM 3740. 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,"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 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 doubl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Woz Machine
The Integrated Woz Machine (or IWM for short) is a single-chip version of the floppy disk controller for the Apple II. It was also employed in Macintosh computers. History When developing a floppy drive for the Apple II, Apple Inc. co-founder Steve Wozniak felt that the existing models available on the market were too complicated, expensive and inefficient. Rather than use the existing floppy drives from Shugart Associates, Wozniak decided to use the drive mechanism – but develop his own electronics separately for the both drive and the controller. Wozniak successfully came up with a working floppy drive with a greatly reduced number of electronic components. Instead of storing 8–10 sectors (each holding 256 bytes of data) per track on a 5.25-inch floppy disk — something standard at that time, Wozniak utilized group-coded recording (GCR), and with 5-and-3 encoding he managed to squeeze as many as 13 sectors on each track using the same mechanics and the same stor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
