MOS Technology 6502
The MOS Technology 6502 is an 8-bit microprocessor, designed by a small team led by Chuck Peddle for MOS Technology. When it was introduced in 1975, the 6502 was, by a considerable margin, the least expensive microprocessor on the market, it sold for less than one-sixth the cost of competing designs from larger companies, such as Motorola and Intel, caused rapid decreases in pricing across the entire processor market. Along with the Zilog Z80, it sparked a series of projects that resulted in the home computer revolution of the early 1980s. Popular home video game consoles and computers, such as the Atari 2600, Atari 8-bit family, Apple II, Nintendo Entertainment System, Commodore 64, Atari Lynx, BBC Micro and others, used the 6502 or variations of the basic design. Soon after the 6502's introduction, MOS Technology was purchased outright by Commodore International, who continued to sell the microprocessor and licenses to other manufacturers. In the early days of the 6502, it was second-sourced by Rockwell and Synertek, licensed to other companies.
In its CMOS form, developed by the Western Design Center, the 6502 family continues to be used in embedded systems, with estimated production volumes in the hundreds of millions. The 6502 was designed by many of the same engineers that had designed the Motorola 6800 microprocessor family. Motorola started the 6800 microprocessor project in 1971 with Tom Bennett as the main architect; the chip layout began in late 1972, the first 6800 chips were fabricated in February 1974 and the full family was released in November 1974. John Buchanan was the designer of the 6800 chip and Rod Orgill, who did the 6501, assisted Buchanan with circuit analyses and chip layout. Bill Mensch joined Motorola in June 1971 after graduating from the University of Arizona, his first assignment was helping define the peripheral ICs for the 6800 family and he was the principal designer of the 6820 Peripheral Interface Adapter. Motorola's engineers could run digital simulations on an IBM 370-165 mainframe computer. Bennett hired Chuck Peddle in 1973 to do architectural support work on the 6800 family products in progress.
He contributed in many areas, including the design of the 6850 ACIA. Motorola's target customers were established electronics companies such as Hewlett-Packard, Tektronix, TRW, Chrysler. In May 1972, Motorola's engineers began visiting select customers and sharing the details of their proposed 8-bit microprocessor system with ROM, RAM, parallel and serial interfaces. In early 1974, they provided engineering samples of the chips so that customers could prototype their designs. Motorola's "total product family" strategy did not focus on the price of the microprocessor, but on reducing the customer's total design cost, they offered development software on a timeshare computer, the "EXORciser" debugging system, onsite training and field application engineer support. Both Intel and Motorola had announced a $360 price for a single microprocessor; the actual price for production quantities was much less. Motorola offered a design kit containing the 6800 with six support chips for $300. Peddle, who would accompany the sales people on customer visits, found that customers were put off by the high cost of the microprocessor chips.
To lower the price, the IC chip size would have to shrink so that more chips could be produced on each silicon wafer. This could be done by removing inessential features in the 6800 and using a newer fabrication technology, "depletion-mode" MOS transistors. Peddle and other team members started outlining the design of an improved feature, reduced size microprocessor. At that time, Motorola's new semiconductor fabrication facility in Austin, was having difficulty producing MOS chips and mid 1974 was the beginning of a year-long recession in the semiconductor industry. Many of the Mesa, employees were displeased with the upcoming relocation to Austin. Motorola Semiconductor Products Division's management was overwhelmed with problems and showed no interest in Peddle's low-cost microprocessor proposal. Chuck Peddle was frustrated with Motorola's management for missing this new opportunity. In a November 1975 interview, Motorola's Chairman, Robert Galvin, agreed, he said, "We did not choose the right leaders in the Semiconductor Products division."
The division was reorganized and the management replaced. New group vice-president John Welty said, "The semiconductor sales organization lost its sensitivity to customer needs and couldn't make speedy decisions."Peddle began looking for a source of funding for this new project and found a small semiconductor company in Pennsylvania. In August 1974, Chuck Peddle, Bill Mensch, Rod Orgill, Harry Bawcom, Ray Hirt, Terry Holdt and Wil Mathys left Motorola to join MOS Technology. Of the seventeen chip designers and layout people on the 6800 team, seven left. There were 30 to 40 application engineers and system engineers on the 6800 team; that December, Gary Daniels transferred into the 6800 microprocessor group. Tom Bennett did not want to leave the Phoenix area so Daniels took over the microprocessor development in Austin, his first project was a "depletion-mode" version of the 6800. The faster parts were available in July 1976; this was followed by the 6802 which added 128 bytes of an on-chip clock oscillator circuit.
MOS Technology was formed in 1969 by three executives from General Instrument, Mort Jaffe, Don McLaughlin, John Pavinen, to produce metal-oxide-semiconductor integrated circuits. Allen-Br
Atari 8-bit family
The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 and manufactured until 1992. All of the machines in the family are technically similar and differ in packaging, they are based on the MOS Technology 6502 CPU running at 1.79 MHz, were the first home computers designed with custom co-processor chips. This architecture enabled graphics and sound capabilities that were more advanced than contemporary machines at the time of release, gaming on the platform was a major draw. Star Raiders is considered the platform's killer app; the original Atari 400 and 800 models launched with a series of plug-n-play peripherals that used the Atari SIO serial bus system, an early analog of the modern USB. To meet stringent FCC requirements, the early machines were enclosed in a cast aluminum block, which made them physically robust but expensive to produce. Over the following decade, the 400 and 800 were replaced by the XL series the XE; the XL and XE are much lighter in construction and less expensive to build, while having Atari BASIC built-in and reducing the number of joystick ports from 4 to 2.
The 130XE, released in 1985, increased the memory to 128K of bank-switched RAM. The Atari 8-bit computer line sold two million units during its major production run between late 1979 and mid-1985, they were not only sold through dedicated computer retailers, but department stores such as Sears, using an in-store demo to attract customers. The primary competition in the worldwide market came several years when the Commodore 64 was introduced in 1982; this was the first computer to offer similar graphics performance, went on to be the best selling computer of the 8-bit era. Atari found a strong market in Eastern Europe and had something of a renaissance in the early 1990s as these countries joined a uniting Europe. In 1992, Atari Corp. dropped all remaining support of the 8-bit line. Some time in 1975, Steve Jobs called his former boss at Atari, Al Alcorn, Vice President of Engineering. Jobs was sourcing components for the soon-to-released Apple II, asked Alcorn if he knew of a good switched mode power supply.
Such devices were commercially available. Alcorn instead suggested. Holt worked in Atari's consumer division and had become a leading expert on power supplies, at that time was between projects. Instead, Jobs hired Holt away from Atari, offering him "a ton of stock". Jobs began hiring many Atari engineers and refused to stop this behaviour when asked. In response, Joe Keenan, one of Atari's co-founders, began a project to make an Apple II clone machine, which Atari could produce for much less than Apple, they began design work. It was not long after that news of this project reached Jobs, two weeks he agreed to stop poaching Atari staff; the project was cancelled, ending Atari's first attempt at a personal computer. Design of the 8-bit series of machines started at Atari as soon as the Atari 2600 games console was released in late 1977. While designing the 2600 in 1976, the engineering team from Atari Grass Valley Research Center felt that the 2600 would have about a three-year lifespan before becoming obsolete.
They started blue sky designs for a new console that would be ready to replace it around 1979. What they ended up with was a updated version of the 2600, fixing its more obvious limitations but sharing a similar overall design philosophy; the newer design would be faster than the 2600, have better graphics, would include much better sound hardware. Work on the chips for the new system continued throughout 1978 and focused on much-improved video hardware known as the CTIA. During the early development period, the home computer era began in earnest in the form of the TRS-80, Commodore PET, Apple II family—what Byte Magazine would dub the "1977 Trinity". Nolan Bushnell sold Atari to Warner Communications for $28 million in 1976 in order to raise funds for the launch of the 2600. Warner had sent Ray Kassar to act as the CEO of the company. Kassar felt. In order to adapt the machine to this role, it would need to support character graphics, include some form of expansion for peripherals, run the then-universal BASIC programming language.
The 2600 had no bitmap graphics support or a character generator, all on-screen graphics were created using Player-Missile graphics and a simple background using fixed patterns. The CTIA was designed on the same model, mainly used sprites for drawing. Instead of expanding the CTIA to handle these tasks, the designers introduced an new chip for this purpose, the Alphanumeric Television Interface Controller, or ANTIC; the CTIA and ANTIC worked together to produce a complete display, with the CTIA in charge of sprites and producing color video output, the ANTIC in charge of bitmap and character graphics. Management identified two sweet spots for the new computers: a low-end version known as "Candy", a higher-end machine known as "Colleen"; the primary difference between the two models was marketing. Colleen included user-accessible expansion slots for RAM and ROM, two 8 KB ROM cartridge slots, RF and monitor output and a full keyboard. Candy was designed as a games console, lacking a keyboard and input/output ports, although an external keyboard was planned tha
A ROM cartridge referred to as a cartridge or cart, is a removable memory card containing ROM designed to be connected to a consumer electronics device such as a home computer, video game console and to a lesser extent, electronic musical instruments. ROM cartridges can be used to load software such as other application programs; the cartridge slot could be used for hardware additions, for example speech synthesis. Some cartridges had battery-backed static random-access memory, allowing a user to save data such as game progress or scores between uses. ROM cartridges allowed the user to load and access programs and data without the expense of a floppy drive, an expensive peripheral during the home computer era, without using slow and unreliable Compact Cassette tape. An advantage for the manufacturer was the relative security of the software in cartridge form, difficult for end users to replicate. However, cartridges were expensive to manufacture compared to making a floppy disk or CD-ROM; as disk drives became more common and software expanded beyond the practical limits of ROM size, cartridge slots disappeared from game consoles and personal computers.
Cartridges are still used today with handheld gaming consoles such as the Nintendo DS, Nintendo 3DS, PlayStation Vita, the tablet-like hybrid console Nintendo Switch. Due to its widespread usage for video gaming, ROM cartridges were colloquially referred to as a game cartridge. ROM cartridges were popularized by early home computers which featured a special bus port for the insertion of cartridges containing software in ROM. In most cases the designs were crude, with the entire address and data buses exposed by the port and attached via an edge connector; the Texas Instruments TI 59 family of programmable scientific calculators used interchangeable ROM cartridges that could be installed in a slot at the back of the calculator. The calculator came with a module that provides several standard mathematical functions including solution of simultaneous equations. Other modules were specialized for financial calculations, or other subject areas, a "games" module. Modules were not user-programmable.
The Hewlett-Packard HP-41C had expansion slots which could hold ROM memory as well as I/O expansion ports. Notable computers using cartridges in addition to magnetic media were the Commodore VIC-20 and 64, MSX standard, the Atari 8-bit family, the Texas Instruments TI-99/4A and the IBM PCjr; some arcade system boards, such as Capcom's CP System and SNK's Neo Geo used ROM cartridges. The modern take on game cartridges was invented by Jerry Lawson as part of the Fairchild Channel F home console in 1976; the cartridge approach gained more popularity with the Atari 2600 released the following year. From the late 1970s to mid-1990s, the majority of home video game systems were cartridge-based; as compact disc technology came to be used for data storage, most hardware companies moved from cartridges to CD-based game systems. Nintendo remained the lone hold-out. SNK still released games on the cartridge-based Neo Geo until 2004, with the final official release being Samurai Shodown V Special. Nintendo's handheld consoles, continued to use cartridges due to their faster loading times and minimal equipment for data reading being beneficial for playing video games in short, several-minute intervals.
ROM cartridges can not only additional hardware expansion as well. Examples include the Super FX coprocessor chip in some Super NES game paks, The SVP chip in the Sega Genesis Version Of Virtua Racing, voice and chess modules in the Magnavox Odyssey². Micro Machines 2 on the Genesis/Mega Drive used a custom "J-Cart" cartridge design by Codemasters which incorporated two additional gamepad ports; this allowed players to have up to four gamepads connected to the console without the need for an additional multi-controller adapter. The ROM cartridge slot principle continues in various mobile devices, thanks to the development of high density low-cost flash memory. For example, a GPS navigation device might allow user updates of maps by inserting a flash memory chip into an expansion slot. An E-book reader can store the text of several thousand books on a flash chip. Personal computers may allow the user to boot and install an operating system off a USB flash drive instead of CD ROM or floppy disks.
Digital cameras with flash drive slots allow users to exchange cards when full, allow rapid transfer of pictures to a computer or printer. Storing software on ROM cartridges has a number of advantages over other methods of storage like floppy disks and optical media; as the ROM cartridge is memory mapped into the system's normal address space, software stored in the ROM can be read like normal memory. Software run directly from ROM uses less RAM, leaving memory free for other processes. While the standard size of optical media dictates a minimum size for devices which can read disks, ROM cartridges can be manufactured in different sizes, allowing for smaller devices like handheld game systems. ROM cartridges can be damaged, but they are more robust and resistant to damage than optical media.
In computing, spooling is a specialized form of multi-programming for the purpose of copying data between different devices. In contemporary systems it is used for mediating between a computer application and a slow peripheral, such as a printer. Spooling allows programs to "hand off" work to be done by the peripheral and proceed to other tasks, or do not begin until input has been transcribed. A dedicated program, the spooler, maintains an orderly sequence of jobs for the peripheral and feeds it data at its own rate. Conversely, for slow input peripherals, such as a card reader, a spooler can maintain a sequence of computational jobs waiting for data, starting each job when all of the relevant input is available; the spool itself refers to the storage area where they are held. In many cases the spooler is able to drive devices at their full rated speed with minimal impact on other processing. Spooling is a combination of queueing. Nowadays, the most common use of spooling is printing: documents formatted for printing are stored in a queue at the speed of the computer retrieved and printed at the speed of the printer.
Multiple processes can write documents to the spool without waiting, can perform other tasks, while the "spooler" process operates the printer. For example, when a large organization prepares payroll cheques, the computation takes only a few minutes or seconds, but the printing process might take hours. If the payroll program printed cheques directly, it would be unable to proceed to other computations until all the cheques were printed. Before spooling was added to PC operating systems, word processors were unable to do anything else, including interact with the user, while printing. Spooler or print management software includes a variety of related features, such as allowing priorities to be assigned to print jobs, notifying users when their documents have been printed, distributing print jobs among several printers, selecting appropriate paper for each document, etc. A print server applies spooling techniques to allow many computers to share the same printer or group of printers. Print spoolers can be configured to add a banner page to the front of each document.
These separate documents from each other, identify each document and also state who printed it. Banner pages are valuable in office environments. Depending on the configuration, banner pages might be generated on each client computer, or on a centralized print server, or by the printer itself. On printers using fanfold continuous forms a leading banner page would be printed twice, so that one copy would always be face-up when the jobs were separated; the page might include lines printed over the fold, which would be visible along the edge of a stack of printed output, allowing the operator to separate the jobs. Some systems would print a banner page at the end of each job, assuring users that they had collected all of their printout. Spooling is used to mediate access to punched card readers and punches, magnetic tape drives, other slow, sequential I/O devices, it allows the application to run at the speed of the CPU while operating peripheral devices at their full rates speed. A batch processing system uses spooling to maintain a queue of ready-to-run tasks, which can be started as soon as the system has the resources to process them.
Some store and forward messaging systems, such as uucp, used "spool" to refer to their inbound and outbound message queues, this terminology is still found in the documentation for email and Usenet software though messages are delivered nowadays. Peripheral devices have always been much slower than core processing units; this was an severe problem for early mainframes. For example, a job which read punched cards or generated printed output directly was forced to run at the speed of the slow mechanical devices; the first spooling programs, such as IBM's "SPOOL System" copied data from punched cards to magnetic tape, from tape back to punched cards and printers. Hard disks, which are faster and support random access, started to replace this use of magnetic tape in the middle 1960s, by the 1970s had eliminated this use of tape; because the unit record equipment on IBM mainframes of the early 1960s was so slow, it was common to use a small offline machine such as a 1401 instead of spooling. The term "spool" originates with the Simultaneous Peripheral Operations On-Line software.
Its derivation is uncertain. Simultaneous peripheral operations on-line may be a backronym. Another explanation is that it refers to reels of magnetic tape. IBM SPOOL System, 7070-IO-076 Integrated facility of various operating systems, e.g. GCOS, OS/360 Attached Support Processor in OS/360 and OS/VS2. Houston Automatic Spooling Priority, prominent in the 1960s Job Entry Subsystem 2, a follower of HASP Job Entry Subsystem 3, a follower of ASP Priority Output Writers, Execution Processors and Input Readers GRASP The Spooler, IBM DOS/360, DOS/VS, DOS/VSE spooler, 1975–1980s The Berkeley printing system CUPS VM/370 RSCS
Antic was a home computer magazine devoted to the Atari 8-bit family. It was named after the ANTIC chip; the magazine was published from April 1982 until June/July 1990. Antic printed type-in programs and tutorials, among other articles; each issue contained one type-in game as "Game of the Month." Its main rival in the United States was ANALOG Computing, another long-lived magazine devoted to the Atari 8-bit line. COMPUTE! and Family Computing served Atari 8-bit owners with type-in programs, though they covered other 8-bit home computers as well. NASA programmer Jim Capparell was an early Atari 8-bit owner, he quit his job on 15 January 1982 to found a magazine for the computer. Companies such as On-Line Systems and Synapse Software agreed to purchase advertising in the new publication, Capparell's staff distributed the first issue of 30 pages at the March 1982 West Coast Computer Faire; the first issue of Antic was published in April 1982. While it began as a bimonthly magazine, within a year it had gone monthly.
By Christmas 1983 the magazine was 148 pages, but in 1984 Antic saw advertising sales drop by 50% in 90 days. The Antic Software catalog, bound into each issue, contained public domain software, re-released products from the Atari Program Exchange after it folded, original titles, it helped the company avoid bankruptcy, in 1985 it started II Computing for the Apple II series. In 1985 Antic began a section of the magazine devoted to the Atari ST line. In 1986 it began STart Magazine for the computer; the daughter magazine would outlive its parent by about a year. When Antic ended, it continued as a section of STart. A magazine for the Commodore Amiga, the primary competitor of the Atari ST, was published from 1989 until 1991 under the name Antic's Amiga Plus; the last issue of Antic was June–July 1990. All told, 88 issues were published. A "Best of" book was published. A utility called, it generates a checksum for each Atari BASIC line entered in a program. By comparing each line's checksum with that printed in the magazine, the reader could be sure they typed the BASIC source correctly.
TYPO was succeeded by TYPO II, a smaller, faster program. Versions of TYPO were published and used by Page 6 magazine. Antic Software – The software company founded by Antic. Antic Magazine – At the Classic Computer Magazine Archive Antic at the Internet Archive The Antic Magazine Library at the Centre for Computing History
An edge connector is the portion of a printed circuit board consisting of traces leading to the edge of the board that are intended to plug into a matching socket. The edge connector is a money-saving device because it only requires a single discrete female connector, they tend to be robust and durable, they are used in computers for expansion slots for peripheral cards, such as PCI, PCI Express, AGP cards. Edge connector sockets consist of a plastic "box" open on one side, with pins on one or both side of the longer edges, sprung to push into the middle of the open center. Connectors are keyed to ensure the correct polarity, may contain bumps or notches both for polarity and to ensure that the wrong type of device is not inserted; the socket's width is chosen to fit to the thickness of the connecting PCB. The opposite side of the socket is an insulation-piercing connector, clamped onto a ribbon cable. Alternatively, the other side may be soldered to a daughtercard. Edge connectors are used in personal computers for connecting expansion cards and computer memory to the system bus.
Example expansion peripheral technologies which use edge connectors include PCI, PCI Express, AGP. Slot 1 and Slot A used edge connectors. IBM PCs used edge connector sockets attached to ribbon cables to connect 5.25" floppy disk drives. 3.5" drives use a pin connector instead. Video game cartridges take the form of a PCB with an edge connector: the socket is located within the console itself; the Nintendo Entertainment System was unusual in that it was designed to use a zero insertion force edge connector: instead of the user forcing the cartridge into the socket directly, the cartridge was first placed in a bay and mechanically lowered into position. Pin header connector Insulation-displacement connector