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Disk II
The Disk II Floppy Disk Subsystem, often rendered as Disk ] '', is a -inch floppy disk drive designed by Apple Computer, Inc. It went on sale in June 1978 at a retail price of US$495 for pre-order; it was later sold for $595 () including the Disk controller">controller card (which can control up to two drives) and cable. The Disk II was designed specifically for use with the Apple II personal computer family to replace the slower Cassette tape#Data recording, cassette tape storage. These floppy drives cannot be used with any Macintosh without an Apple IIe Card as doing so will damage the drive or the controller. Apple produced at least six variants of the basic -inch Disk II concept over the course of the Apple II series' lifetime: The Disk II, the Disk III, the DuoDisk, the Disk IIc, the UniDisk 5.25" and the Apple 5.25 Drive. While all of these drives look different, and use four different connector types, they're all electronically extremely similar. They can all use the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disk II
The Disk II Floppy Disk Subsystem, often rendered as Disk ] '', is a -inch floppy disk drive designed by Apple Computer, Inc. It went on sale in June 1978 at a retail price of US$495 for pre-order; it was later sold for $595 () including the Disk controller">controller card (which can control up to two drives) and cable. The Disk II was designed specifically for use with the Apple II personal computer family to replace the slower Cassette tape#Data recording, cassette tape storage. These floppy drives cannot be used with any Macintosh without an Apple IIe Card as doing so will damage the drive or the controller. Apple produced at least six variants of the basic -inch Disk II concept over the course of the Apple II series' lifetime: The Disk II, the Disk III, the DuoDisk, the Disk IIc, the UniDisk 5.25" and the Apple 5.25 Drive. While all of these drives look different, and use four different connector types, they're all electronically extremely similar. They can all use the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hewlett-Packard
The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components, as well as software and related services to consumers, small and medium-sized businesses ( SMBs), and large enterprises, including customers in the government, health, and education sectors. The company was founded in a one-car garage in Palo Alto by Bill Hewlett and David Packard in 1939, and initially produced a line of electronic test and measurement equipment. The HP Garage at 367 Addison Avenue is now designated an official California Historical Landmark, and is marked with a plaque calling it the "Birthplace of 'Silicon Valley'". The company won its first big contract in 1938 to provide test and measurement instruments for Walt Disney's production of the animated film ''Fantasia'', which allowed Hewlett and Packard to formally esta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PC Magazine
''PC Magazine'' (shortened as ''PCMag'') is an American computer magazine published by Ziff Davis. A print edition was published from 1982 to January 2009. Publication of online editions started in late 1994 and have continued to the present day. Overview ''PC Magazine'' provides reviews and previews of the latest hardware and software for the information technology professional. Articles are written by leading experts including John C. Dvorak, whose regular column and "Inside Track" feature were among the magazine's most popular attractions. Other regular departments include columns by long-time editor-in-chief Michael J. Miller ("Forward Thinking"), Bill Machrone, and Jim Louderback, as well as: * "First Looks" (a collection of reviews of newly released products) * "Pipeline" (a collection of short articles and snippets on computer-industry developments) * "Solutions" (which includes various how-to articles) * "User-to-User" (a section in which the magazine's experts answ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRS-80 Model I
The TRS-80 Micro Computer System (TRS-80, later renamed the Model I to distinguish it from successors) is a desktop microcomputer launched in 1977 and sold by Tandy Corporation through their Radio Shack stores. The name is an abbreviation of ''Tandy Radio Shack, Z80 icroprocessor'. It is one of the earliest mass-produced and mass-marketed retail home computers. The TRS-80 has a full-stroke QWERTY keyboard, the Zilog Z80 processor, 4 KB dynamic random-access memory (DRAM) standard memory, small size and desk area, floating-point Level I BASIC language interpreter in read-only memory (ROM), 64-character per line video monitor, and a starting price of US$600 (equivalent to US$ in ). A cassette tape drive for program storage was included in the original package. While the software environment was stable, the cassette load/save process combined with keyboard bounce issues and a troublesome Expansion Interface contributed to the Model I's reputation as not well-suited to serious ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byte (magazine)
''Byte'' (stylized as ''BYTE'') was a microcomputer magazine, influential in the late 1970s and throughout the 1980s because of its wide-ranging editorial coverage. "''Byte'' magazine, the leading publication serving the homebrew market ..." ''Byte'' started in 1975, shortly after the first personal computers appeared as kits advertised in the back of electronics magazines. ''Byte'' was published monthly, with an initial yearly subscription price of $10. Whereas many magazines were dedicated to specific systems or the home or business users' perspective, ''Byte'' covered developments in the entire field of "small computers and software", and sometimes other computing fields such as supercomputers and high-reliability computing. Coverage was in-depth with much technical detail, rather than user-oriented. The company was purchased by McGraw-Hill in 1979, a watershed event that led to the rapid purchase of many of the early computer magazines by larger publishers. By this time t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VisiCalc
VisiCalc (for "visible calculator") is the first spreadsheet computer program for personal computers, originally released for Apple II by VisiCorp on 17 October 1979. It is often considered the application that turned the microcomputer from a hobby for computer enthusiasts into a serious business tool, prompting IBM to introduce the IBM PC two years later. VisiCalc is considered to be Apple II's killer app. It sold over 700,000 copies in six years, and as many as 1 million copies over its history. Initially developed for the Apple II computer using a 6502 assembler running on the Multics time sharing system, VisiCalc was ported to numerous platforms, both 8-bit and some of the early 16-bit systems. In order to do this, the company developed porting platforms that produced bug compatible versions. The company took the same approach when the IBM PC was launched, producing a product that was essentially identical to the original 8-bit Apple II version. Sales were initially brisk, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Frequency Modulation
In telecommunication, 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'') underg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft-sectored
Floppy disk format and density refer to the logical and physical layout of data stored on a floppy disk. Since their introduction, there have been many popular and rare floppy disk types, densities, and formats used in computing, leading to much confusion over their differences. In the early 2000s, most floppy disk types and formats became obsolete, leaving the -inch disk, using an IBM PC compatible format of 1440 KB, as the only remaining popular format. Different floppy disk types had different recording characteristics, with varying magnetic coercivity (measured in oersteds, or in modern SI units in amperes per meter), ferrite grain size, and tracks per inch (TPI). TPI was not a part of the physical manufacturing process; it was a certification of how closely cylinder-head-sector, tracks of data could be spaced on the medium safely. The term density has a double meaning for floppy disks. Originally, single density and double density indicated a difference in logical enc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Star Computers
North Star Computers Inc. (later styled as NorthStar) was an American computer company based in Berkeley, California existing between June 1976 (when according to popular rumor it was formed as "Kentucky Fried Computers") and 1989. Originally a mail order business for IMSAI computers, it soon developed into a major player in the early microcomputer market, becoming first known for their low-cost floppy disk system for S-100 bus machines, and later for their own S-100 bus computers running either the CP/M operating system or North Star's own proprietary operating system, NSDOS. North Star BASIC was a common dialect of the popular BASIC programming language. They later expanded their lineup with dual-CPU machines able to run MS-DOS, and a server version running either DOS or Novell NetWare. While initially successful, North Star's sales suffered from the company's adherence to hard sector floppy drives which made software difficult to port onto North Star machines. It was no longer a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steve Jobs
Steven Paul Jobs (February 24, 1955 – October 5, 2011) was an American entrepreneur, industrial designer, media proprietor, and investor. He was the co-founder, chairman, and CEO of Apple; the chairman and majority shareholder of Pixar; a member of The Walt Disney Company's board of directors following its acquisition of Pixar; and the founder, chairman, and CEO of NeXT. He is widely recognized as a pioneer of the personal computer revolution of the 1970s and 1980s, along with his early business partner and fellow Apple co-founder Steve Wozniak. Jobs was born in San Francisco to a Syrian father and German-American mother. He was adopted shortly after his birth. Jobs attended Reed College in 1972 before withdrawing that same year. In 1974, he traveled through India seeking enlightenment before later studying Zen Buddhism. He and Wozniak co-founded Apple in 1976 to sell Wozniak's Apple I personal computer. Together the duo gained fame and wealth a year later with produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
