The Macintosh SE is a personal computer designed and sold by Apple Computer, Inc. from March 1987 to October 1990. It marked a significant improvement on the Macintosh Plus design and was introduced by Apple at the same time as the Macintosh II; the SE retains the same Compact Macintosh form factor as the original Macintosh computer introduced three years earlier and uses the same design language used by the Macintosh II. An enhanced model, the SE/30 was introduced in January 1989; the Macintosh SE was updated in August 1989 to include a SuperDrive, with this updated version being called the "Macintosh SE FDHD" and the "Macintosh SE SuperDrive". The Macintosh SE was replaced with the Macintosh Classic, a similar model which retained the same central processing unit and form factor, but at a lower price point; the Macintosh SE was introduced at the AppleWorld conference in Los Angeles on March 2, 1987. The "SE" is an acronym for "System Expansion", its notable new features, compared to its similar predecessor, the Macintosh Plus, were: First compact Macintosh with an internal drive bay for a hard disk or a second floppy drive.
First compact Macintosh. First Macintosh to support the Apple Desktop Bus only available on the Apple IIGS, for keyboard and mouse connections. Improved SCSI support with a standard 50-pin internal SCSI connector. Better reliability and longer life expectancy due to the addition of a cooling fan. Upgraded video circuitry that results in a lower percentage of CPU time being spent drawing the screen. In practice this results in a 10-20 percent performance improvement. Additional fonts and kerning routines in the Toolbox ROM Disk First Aid is included on the system diskThe SE and Macintosh II were the first Apple computers since the Apple I to be sold without a keyboard. Instead the customer was offered the choice of the new ADB Apple Keyboard or the Apple Extended Keyboard. Apple produced ten SEs with transparent cases as prototypes for promotional employees, they are rare and command a premium price for collectors. The Macintosh SE shipped with System 4.0 and Finder 5.4. The README file included with the installation disks for the SE and II is the first place Apple used the term "Macintosh System Software", after 1998 these two versions were retroactively given the name "Macintosh System Software 2.0.1".
Processor: Motorola 68000, 8 MHz, with an 8 MHz system bus and a 16-bit data path RAM: The SE came with 1 MB of RAM as standard, is expandable to 4 MB. The logic board has four 30-pin SIMM slots. Video: There is 256 KB of onboard video memory, enabling 512x384 monochrome resolution; the built-in screen has a lower resolution. Storage: The SE can accommodate either one or two floppy drives, or a floppy drive and a hard drive. After-market brackets were designed to allow the SE to accommodate two floppy drives as well as a hard drive, however it was not a configuration supported by Apple. In addition an external floppy disk drive may be connected, making the SE the only Macintosh besides the Macintosh Portable and Macintosh II which could support three floppy drives, though its increased storage, RAM capacity and optional internal hard drive rendered the external drives less of a necessity than for its predecessors. Single-floppy SE models featured a drive-access light in the spot where the second floppy drive would be.
Hard-drive equipped models came with a 20 MB SCSI hard disk. Battery: Located on the logic board is a 3.6 V lithium battery, which must be present in order for basic settings to persist between power cycles. Macintosh SE machines which have sat for a long time have experienced battery corrosion and leakage, resulting in a damaged case and logic board. Expansion: A Processor Direct Slot on the logic board allows for expansion cards, such as accelerators, to be installed; the SE can be upgraded to more than 5 MB with the MicroMac accelerators. In the past other accelerators were available such as the Sonnet Allegro. Since installing a card required opening the computer's case and exposing the user to high voltages from the internal CRT, Apple recommended that only authorized Apple dealers install the cards. Upgrades: After Apple introduced the Macintosh SE/30 in January, 1989, a logic board upgrade was sold by Apple dealers as a high-cost upgrade for the SE, consisting of a new SE/30 motherboard, case front and internal chassis to accommodate the upgrade components.
Easter egg: The Macintosh SE ROM size increased from 64 KB in the original Mac to 256 KB, which allowed the development team to include an Easter Egg hidden in the ROMs. By jumping to address 0x41D89A or reading from the ROM chips it is possible to display the four images of the engineering team. Introduced March 2, 1987: Macintosh SEIntroduced August 1, 1989: Macintosh SE FDHD: Includes the new SuperDrive, a floppy disk drive that can handle 1.4 MB High Density floppy disks. FDHD is an acronym for "Floppy Disk High Density". High-density floppies would become the de facto standard on both the Macintosh and PC computers from on. An upgrade kit was sold for the original Macintosh SE which included new ROM chips and a new disk controller chip, to replace the originals. Macintosh SE 1/20: The name of the Macintosh SE FD
The Macintosh 512K is a personal computer, designed and sold by Apple Computer, inc. from September 1984 to April 1986. It is the first update to the original Macintosh 128K, it was identical to the previous Macintosh, differing in the amount of built-in random-access memory. The increased memory turned the Macintosh into a more business-capable computer and gained the ability to run more software; the Mac 512K shipped with Macintosh System 1.1 but was able to run all versions of Mac OS up to System 4.1. It was replaced by the Macintosh Plus. All support for the Mac 512K was discontinued on September 1, 1998. Like the Macintosh 128K before it, the 512K contained a Motorola 68000 connected to a 512 kB DRAM by a 16-bit data bus. Though the memory had been quadrupled, it could not be upgraded; the large increase earned it the nickname Fat Mac. A 64 kB ROM chip boosts the effective memory to 576 kB, but this is offset by the display's 22 kB framebuffer, shared with the DMA video controller; this shared arrangement reduces CPU performance by up to 35%.
It shared a revised logic board with the re-badged Macintosh 128K. The resolution of the display was the same, at 512x342. Apple sold a memory upgrade for the Macintosh 128K for $995 and reduced the price when 256K DRAM prices fell months later; the applications MacPaint and MacWrite were still bundled with the Mac. Soon after this model was released, several other applications became available, including MacDraw, MacProject, Macintosh Pascal and others. In particular, Microsoft Excel, written for the Macintosh, required a minimum of 512 kB of RAM, but solidified the Macintosh as a serious business computer. Models with the enhanced ROM supported Apple's Switcher, allowing cooperative multitasking among applications; the LaserWriter printer became available shortly after the 512K's introduction, as well as the number pad, tablet, mouse, basic mouse, much more. It utilized Apple's built-in networking scheme LocalTalk which allows sharing of devices among several users; the 512K was the oldest Macintosh capable of supporting Apple's AppleShare built-in file sharing network, when introduced in 1987.
The expanded memory in the 512K allowed it to better handle large word-processing documents and make better use of the graphical user interface and increased speed over the 128K model. The original 512K could accept Macintosh system software up to version 4.1. An updated version replaced the Macintosh 512K and debuted as the Macintosh 512K enhanced in April 1986, it differed from the original 512K in that it had an 800 kB floppy disk drive and the same improved ROM as the Macintosh Plus. With the exception of the new model number, they were otherwise cosmetically identical; the stock 512K could use an 800 kB floppy disk drive as well as the Hard Disk 20, the first hard disk manufactured by Apple for use with the 512K, but required a special system file that loaded the improved ROM code into RAM, thus reducing the available RAM for other uses. Apple offered an upgrade kit which replaced the floppy disk drive and ROMs turning it into a 512Ke. One further OEM upgrade replaced the logicboard and the rear case with that of the Macintosh Plus.
As with the original Macintosh, the 512K was designed with no slots for upgrade boards and had no hard-disk controller, so the few internal upgrades that were available for the 512K, such as General Computer's US$2,795 Hyperdrive hard drive, had to plug directly into the 68000 processor socket. Other such upgrades included "snap-on" SCSI cards and RAM upgrades of 2 MB or more. Macintosh 128K/512K technical details Macintosh 512K technical specifications at apple.com Inside the Macintosh 512K
A desktop computer is a personal computer designed for regular use at a single location on or near a desk or table due to its size and power requirements. The most common configuration has a case that houses the power supply, disk storage; the case may be oriented horizontally or vertically and placed either underneath, beside, or on top of a desk. Prior to the widespread use of microprocessors, a computer that could fit on a desk was considered remarkably small. Early computers took up the space of a whole room. Minicomputers fit into one or a few refrigerator-sized racks, it was not until the 1970s when programmable computers appeared that could fit on top of a desk. 1970 saw the introduction of the Datapoint 2200, a "smart" computer terminal complete with keyboard and monitor, was designed to connect with a mainframe computer but that didn't stop owners from using its built in computational abilities as a stand alone desktop computer. The HP 9800 series, which started out as programmable calculators in 1971 but was programmable in BASIC by 1972, used a smaller version of a minicomputer design based on ROM memory and had small one-line LED alphanumeric displays and displayed graphics with a plotter.
The Wang 2200 of 1973 had cassette tape storage. The IBM 5100 in 1975 had a small CRT display and could be programmed in BASIC and APL; these were expensive specialized computers sold for business or scientific uses. Apple II, TRS-80 and Commodore PET were first generation personal home computers launched in 1977, which were aimed at the consumer market – rather than businessmen or computer hobbyists. Byte magazine referred to these three as the "1977 Trinity" of personal computing. Throughout the 1980s and 1990s, desktop computers became the predominant type, the most popular being the IBM PC and its clones, followed by the Apple Macintosh, with the third-placed Commodore Amiga having some success in the mid-1980s but declining by the early 1990s. Early personal computers, like the original IBM Personal Computer, were enclosed in a "desktop case", horizontally oriented to have the display screen placed on top, thus saving space on the user's actual desk, although these cases had to be sturdy enough to support the weight of CRT displays that were widespread at the time.
Over the course of the 1990s, desktop cases became less common than the more-accessible tower cases that may be located on the floor under or beside a desk rather than on a desk. Not only do these tower cases have more room for expansion, they have freed up desk space for monitors which were becoming larger every year. Desktop cases the compact form factors, remain popular for corporate computing environments and kiosks; some computer cases can be interchangeably positioned either horizontally or upright. Influential games such as Doom and Quake during the 1990s had pushed gamers and enthusiasts to upgrade to the latest CPUs and graphics cards for their desktops in order to run these applications, though this has slowed since the late 2000s as the growing popularity of Intel integrated graphics forced game developers to scale back. Creative Technology's Sound Blaster series were a de facto standard for sound cards in desktop PCs during the 1990s until the early 2000s, when they were reduced to a niche product, as OEM desktop PCs came with sound boards integrated directly onto the motherboard.
While desktops have long been the most common configuration for PCs, by the mid-2000s the growth shifted from desktops to laptops. Notably, while desktops were produced in the United States, laptops had long been produced by contract manufacturers based in Asia, such as Foxconn; this shift led to the closure of the many desktop assembly plants in the United States by 2010. Another trend around this time was the increasing proportion of inexpensive base-configuration desktops being sold, hurting PC manufacturers such as Dell whose build-to-order customization of desktops relied on upselling added features to buyers. Battery-powered portable computers had just 2% worldwide market share in 1986. However, laptops have become popular, both for business and personal use. Around 109 million notebook PCs shipped worldwide in 2007, a growth of 33% compared to 2006. In 2008, it was estimated that 145.9 million notebooks were sold, that the number would grow in 2009 to 177.7 million. The third quarter of 2008 was the first time when worldwide notebook PC shipments exceeded desktops, with 38.6 million units versus 38.5 million units.
The sales breakdown of the Apple Macintosh have seen sales of desktop Macs staying constant while being surpassed by that of Mac notebooks whose sales rate has grown considerably. The change in sales of form factors is due to the desktop iMac moving from affordable to upscale and subsequent releases are considered premium all-in-ones. By contrast, the MSRP of the MacBook laptop lines have dropped through successive generations such that the MacBook Air and MacBook Pro constitute the lowest price of entry to a Mac, with the exception of the more inexpensive Mac Mini (albeit with
Lightning is a proprietary computer bus and power connector created by Apple Inc. Introduced on September 12, 2012, to replace its predecessor, the 30-pin dock connector, the Lightning connector is used to connect Apple mobile devices like iPhones, iPads, iPods to host computers, external monitors, cameras, USB battery chargers, other peripherals. Using 8 pins instead of 30, Lightning is more compact than the 30-pin dock connector and can be inserted with either side facing up. However, unless used with an adapter, it is incompatible with cables and peripherals designed for its predecessor; the Lightning connector was introduced on September 12, 2012, as a replacement for the 30-pin dock connector, to be used for all new hardware, announced at the same event. The first compatible devices were the iPhone 5, the iPod Touch, the iPod Nano; the iPad and the iPad Mini were added as Lightning devices in October 2012. On November 25, 2012, Apple acquired the "Lightning" trademark in Europe from Harley-Davidson.
Apple was given a partial transfer of the Lightning trademark, suggesting that Harley-Davidson retained the rights to use the name for motorcycle-related products. Apple is the sole proprietor of the trademark and copyrights for the designs and specifications of the Lightning connector; the iPad Pro, released in 2015, features the first Lightning connector supporting USB 3.0 host. However, the only accessory, that supports USB 3.0 is the new camera adapter. Normal USB-A - Lightning cables are still USB 2.0. On October 30, 2018, Apple announced that their new range of iPads will replace Lightning with USB-C. Lightning is an 8-pin connector. Unlike the Apple 30 pin connector it replaces, the Lightning connector can be inserted either face up or face down. Apple offers various adapters which allow the Lightning connector to be used with other interfaces, such as 30-pin, USB, HDMI, VGA, SD cards; the Lightning to 30-pin adapter supports only a limited subset of the available 30-pin signals: USB data, USB charging, analog audio output.
Official Lightning connectors contain an authentication chip, intended to make it difficult for third-party manufacturers to produce compatible accessories without being approved by Apple. The pin out is detailed in the info box. However, each pin on the reverse side of the connector is connected to its directly opposite twin on the other side. Part of the processor's job is to route the power and data signals whichever way up the connector is inserted; the plug measures 6.7 mm by 1.5 mm. Apple has not publicly discussed microUSB, but various tech news websites state that Lightning might have been used instead of microUSB because of its compatibility with docks and speaker systems; the optional supplemental standard USB On-The-Go allows USB devices to do this. On April 10, 2015, Apple announced a new line of MacBooks that featured USB-C, which has similarities with Lightning, advantages over microUSB. USB-C, like Lightning, but unlike its predecessor microUSB, can be plugged in either direction.
USB-C and Lightning are not interchangeable. The following Apple-made devices use Lightning connectors: iPod Nano iPod Touch iPod Touch Lightning to USB Type C Dock connector Smart Connector Thunderbolt Wingfield, Nick & Chen, Brian X.. "Accessories No Longer Tethered to Apple". The New York Times
The Linux kernel is a free and open-source, Unix-like operating system kernel. The Linux family of operating systems is based on this kernel and deployed on both traditional computer systems such as personal computers and servers in the form of Linux distributions, on various embedded devices such as routers, wireless access points, PBXes, set-top boxes, FTA receivers, smart TVs, PVRs, NAS appliances. While the adoption of the Linux kernel in desktop computer operating system is low, Linux-based operating systems dominate nearly every other segment of computing, from mobile devices to mainframes; as of November 2017, all of the world's 500 most powerful supercomputers run Linux. The Android operating system for tablet computers and smartwatches uses the Linux kernel; the Linux kernel was conceived and created in 1991 by Linus Torvalds for his personal computer and with no cross-platform intentions, but has since expanded to support a huge array of computer architectures, many more than other operating systems or kernels.
Linux attracted developers and users who adopted it as the kernel for other free software projects, notably the GNU Operating System, created as a free, non-proprietary operating system, based on UNIX as a by-product of the fallout of the Unix wars. The Linux kernel API, the application programming interface through which user programs interact with the kernel, is meant to be stable and to not break userspace programs; as part of the kernel's functionality, device drivers control the hardware. However, the interface between the kernel and loadable kernel modules, unlike in many other kernels and operating systems, is not meant to be stable by design; the Linux kernel, developed by contributors worldwide, is a prominent example of free and open source software. Day-to-day development discussions take place on the Linux kernel mailing list; the Linux kernel is released under the GNU General Public License version 2, with some firmware images released under various non-free licenses. In April 1991, Linus Torvalds, at the time a 21-year-old computer science student at the University of Helsinki, started working on some simple ideas for an operating system.
He started with a task switcher in a terminal driver. On 25 August 1991, Torvalds posted the following to comp.os.minix, a newsgroup on Usenet: I'm doing a operating system for 386 AT clones. This has been brewing since April, is starting to get ready. I'd like any feedback on things people like/dislike in minix. I've ported bash and gcc, things seem to work; this implies that I'll get something practical within a few months Yes - it's free of any minix code, it has a multi-threaded fs. It is NOT portable, it never will support anything other than AT-harddisks, as that's all I have:-(. It's in C, but most people wouldn't call what I write C, it uses every conceivable feature of the 386 I could find, as it was a project to teach me about the 386. As mentioned, it uses a MMU, for both paging and segmentation. It's the segmentation; some of my "C"-files are as much assembler as C. Unlike minix, I happen to LIKE interrupts, so interrupts are handled without trying to hide the reason behind them. After that, many people contributed code to the project.
Early on, the MINIX community contributed code and ideas to the Linux kernel. At the time, the GNU Project had created many of the components required for a free operating system, but its own kernel, GNU Hurd, was incomplete and unavailable; the Berkeley Software Distribution had not yet freed itself from legal encumbrances. Despite the limited functionality of the early versions, Linux gained developers and users. In September 1991, Torvalds released version 0.01 of the Linux kernel on the FTP server of the Finnish University and Research Network. It had 10,239 lines of code. On 5 October 1991, version 0.02 of the Linux kernel was released. Torvalds assigned version 0 to the kernel to indicate that it was for testing and not intended for productive use. In December 1991, Linux kernel 0.11 was released. This version was the first to be self-hosted as Linux kernel 0.11 could be compiled by a computer running the same kernel version. When Torvalds released version 0.12 in February 1992, he adopted the GNU General Public License version 2 over his previous self-drafted license, which had not permitted commercial redistribution.
On 19 January 1992, the first post to the new newsgroup alt.os.linux was submitted. On 31 March 1992, the newsgroup was renamed comp.os.linux. The fact that Linux is a monolithic kernel rather than a microkernel was the topic of a debate between Andrew S. Tanenbaum, the creator of MINIX, Torvalds; this discussion is known as the Tanenbaum–Torvalds debate and started in 1992 on the Usenet discussion group comp.os.minix as a general debate about Linux and kernel architecture. Tanenbaum argued that microkernels were superior to monolithic kernels and that therefore Linux was obsolete. Unlike traditional monolithic kernels, device drivers in Linux are configured as loadable kernel modules and are loaded or unloaded while
Apple II series
The Apple II series is a family of home computers, one of the first successful mass-produced microcomputer products, designed by Steve Wozniak, manufactured by Apple Computer, launched in 1977 with the original Apple II. In terms of ease of use and expandability, the Apple II was a major advancement over its predecessor, the Apple I, a limited-production bare circuit board computer for electronics hobbyists. Through 1988, a number of models were introduced, with the most popular, the Apple IIe, remaining changed little into the 1990s. A 16-bit model with much more advanced graphics and sound, the Apple IIGS, was added in 1986. While compatible with earlier Apple II systems, the IIGS was in closer competition with the Atari ST and Amiga; the Apple II was first sold on June 10, 1977. By the end of production in 1993, somewhere between five and six million Apple II series computers had been produced; the Apple II was one of the longest running mass-produced home computer series, with models in production for just under 17 years.
The Apple II became one of several recognizable and successful computers during the 1980s and early 1990s, although this was limited to the USA. It was aggressively marketed through volume discounts and manufacturing arrangements to educational institutions, which made it the first computer in widespread use in American secondary schools, displacing the early leader Commodore PET; the effort to develop educational and business software for the Apple II, including the 1979 release of the popular VisiCalc spreadsheet, made the computer popular with business users and families. The original Apple II operating system was in ROM along with Integer BASIC. Programs were entered saved and loaded on cassette tape; when the Disk II was implemented in 1978 by Steve Wozniak, a Disk Operating System or DOS was commissioned from the company Shepardson Microsystems where its development was done by Paul Laughton. The final and most popular version of this software was Apple DOS 3.3. Some commercial Apple II software did not use standard DOS formats.
This discouraged the modifying of the software on the disks and improved loading speed. Apple DOS was superseded by ProDOS, which supported a hierarchical filesystem and larger storage devices. With an optional third-party Z80-based expansion card, the Apple II could boot into the CP/M operating system and run WordStar, dBase II, other CP/M software. With the release of MousePaint in 1984 and the Apple IIGS in 1986, the platform took on the look of the Macintosh user interface, including a mouse. Despite the introduction of the Motorola 68000-based Macintosh in 1984, the Apple II series still accounted for 85% of the company's hardware sales in the first quarter of fiscal 1985. Apple continued to sell Apple II systems alongside the Macintosh until terminating the IIGS in December 1992 and the IIe in November 1993; the last II-series Apple in production, the IIe card for Macintoshes, was discontinued on October 15, 1993. The total Apple II sales of all of its models during its 16-year production run were about 6 million units, with the peak occurring in 1983 when 1 million were sold.
The Apple II was designed to look more like a home appliance than a piece of electronic equipment. The lid popped off the beige plastic case without the use of tools, allowing access to the computer's internals, including the motherboard with eight expansion slots, an array of random access memory sockets that could hold up to 48 kilobytes worth of memory chips; the Apple II had color and high-resolution graphics modes, sound capabilities and one of two built-in BASIC programming languages. The Apple II was targeted for the masses rather than just engineers. Unlike preceding home microcomputers, it was sold as a finished consumer appliance rather than as a kit. VanLOVEs Apple Handbook and The Apple Educators Guide by Gerald VanDiver and Rolland Love reviewed more than 1,500 software programs that the Apple II series could use; the Apple dealer network used this book to emphasize the growing software developer base in education and personal use. The Apple II series had a keyboard built into the motherboard shell, with the exception of the Apple IIGS which featured an external keyboard.
The Apple II case was durable enough, according to a 1981 Apple ad, to protect an Apple II from a fire started when a cat belonging to one early user knocked over a lamp. Early II-series models were designated "Apple ]["; the first Apple II computers went on sale on June 10, 1977 with a MOS Technology 6502 microprocessor running at 1.023 MHz, 4 KB of RAM, an audio cassette interface for loading programs and storing data, the Integer BASIC programming language built into the ROMs. The video controller displayed 40 columns by 24 lines of monochrome, upper-case-only text on the screen, with NTSC composite video output suitable for display on a TV monitor, or on a regular TV set by way of a separate RF modulator; the original retail price of the computer was US$1298 and US$2638. To reflect the computer's color graphics capability, the Apple logo on the casing was represented using rainbow stripes, which remained a part of Apple's corporate logo until early 1998; the earliest Apple IIs were assembled in Silicon Valley, in Texas.