In telecommunications , a proprietary protocol is a communications protocol owned by a single organization or individual.
88-474: AppleTalk is a discontinued proprietary suite of networking protocols developed by Apple Computer for their Macintosh computers . AppleTalk includes a number of features that allow local area networks to be connected with no prior setup or the need for a centralized router or server of any sort. Connected AppleTalk-equipped systems automatically assign addresses, update the distributed namespace, and configure any required inter-networking routing. AppleTalk
176-538: A Nubus slot in the machine. The new networking stack also expanded the system to allow a full 255 nodes per LAN. With EtherTalk's release, AppleTalk Personal Network was renamed LocalTalk , the name it would be known under for the bulk of its life. Token Ring would later be supported with a similar TokenTalk product, which used the same Network control panel and underlying software. Over time, many third-party companies would introduce compatible Ethernet and Token Ring cards that used these same drivers. The appearance of
264-617: A TCP -style reliable connection-oriented transport was needed. Significant differences from TCP were that: The Apple Filing Protocol (AFP), formerly AppleTalk Filing Protocol, is the protocol for communicating with AppleShare file servers. Built on top of AppleTalk Session Protocol (for legacy AFP over DDP) or the Data Stream Interface (for AFP over TCP), it provides services for authenticating users (extensible to different authentication methods including two-way random-number exchange) and for performing operations specific to
352-620: A "Printers" zone that would list all the printers in an organization, or one might want to place that same device in the "2nd Floor" zone to indicate its physical location. Phase II also included changes to the underlying inter-networking protocols to make them less "chatty", which had previously been a serious problem on networks that bridged over wide-area networks. By this point, Apple had a wide variety of communications products under development, and many of these were announced along with AppleTalk Phase II. These included updates to EtherTalk and TokenTalk, AppleTalk software and LocalTalk hardware for
440-596: A "reference model" (but with customization for the Linotronic's different video interface, plus the necessary implementation of "banding" and a hard drive frame buffer and font storage mechanism). Indeed, the PostScript language itself was concurrently enhanced and extended to support these high-resolution "banding" devices (as contrasted to the lower resolution "framing" devices, such as the LaserWriter, in which
528-528: A Macintosh with a direct Ethernet connection also magnified the Ethernet and LocalTalk compatibility problem: Networks with new and old Macs needed some way to communicate with each other. This could be as simple as a network of Ethernet Mac II's trying to talk to a LaserWriter that only connected to LocalTalk. Apple initially relied on the aforementioned LocalTalk-to-Ethernet bridge products, but contrary to Apple's belief that these would be low-volume products, by
616-414: A bit mask indicating which of the response packets it received, so the responder could retransmit the remainder. ATP could operate in either "at-least-once" mode or "exactly-once" mode. Exactly-once mode was essential for operations which were not idempotent ; in this mode, the responder kept a copy of the response buffers in memory until successful receipt of a release packet from the requestor, or until
704-456: A bridge-connected internet. Additionally, AppleTalk was designed from the start to allow use with any potential underlying physical link, and within a few years, the physical layer would be renamed LocalTalk , so as to differentiate it from the AppleTalk protocols. The main advantage of AppleTalk was that it was completely maintenance-free. To join a device to a network, a user simply plugged
792-399: A client wanted to access that service, it used NBP to query machines to find that service. NBP provided browsability ("what are the names of all the services available?") as well as the ability to find a service with a particular name. Names were human-readable, containing spaces and upper- and lower-case letters, and including support for searching. Proprietary protocol Ownership by
880-504: A free address is found, so for performance purposes the successful address is recorded in NVRAM and used as the default address in the future. This means that in most real-world setups where machines are added a few at a time, only one or two tries are needed before the address effectively becomes constant. The AppleTalk Data Stream Protocol (ADSP) was a comparatively late addition to the AppleTalk protocol suite, done when it became clear that
968-575: A laser printer they intended to market. Jobs was aware of Warnock's efforts, and upon his return to California he began convincing Warnock to allow Apple to license PostScript for a new printer that Apple would sell. Negotiations between Apple and Adobe over the use of PostScript began in 1983 and an agreement was reached in December 1983, one month before Macintosh was announced. Jobs eventually arranged for Apple to buy $ 2.5 million in Adobe stock. At about
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#17327808726941056-714: A market in which the Mac is still important. The LaserWriter was the first major printer designed by Apple to use the new Snow White design language created by Frog Design . It also continued a departure from the beige color that characterized the Apple and Macintosh products to that time by using the same brighter, creamy off-white color first introduced with the Apple IIc and Apple Scribe Printer 8 months earlier. In that regard it and its successors stood out among all of Apple's Macintosh product offerings until 1987, when Apple adopted
1144-487: A name. The NBP lists were examined and displayed by a program known as the Chooser which would display a list of machines on the local network, divided into classes such as file-servers and printers. An AppleTalk address was a four-byte quantity. This consisted of a two-byte network number, a one-byte node number, and a one-byte socket number. Of these, only the network number required any configuration, being obtained from
1232-482: A new networking system based on the AppleBus hardware. This new system would not have to conform to any existing preconceptions, and was designed to be worthy of the Mac – a system that was user-installable and required no configuration or fixed network addresses – in short, a true plug-and-play network. Considerable effort was needed, but by the time the Mac was released, the basic concepts had been outlined, and some of
1320-489: A number of basic networking-like protocols like IBM's Bisync . The SCC was chosen because it would allow multiple devices to be attached to the port. Peripherals equipped with similar SCCs could communicate using the built-in protocols, interleaving their data with other peripherals on the same bus. This would eliminate the need for more ports on the back of the machine, and allowed for the elimination of expansion slots for supporting more complex devices. The initial concept
1408-586: A router. Each node dynamically chose its own node number, according to a protocol (originally the LocalTalk Link Access Protocol LLAP and later, for Ethernet/EtherTalk, the AppleTalk Address Resolution Protocol, AARP) which handled contention between different nodes accidentally choosing the same number. For socket numbers, a few well-known numbers were reserved for special purposes specific to
1496-517: A single four-conductor phone cable. Other companies took advantage of the SCC's ability to read external clocks in order to support higher transmission speeds, up to 1 Mbit/s. In these systems, the external adaptor also included its own clock , and used that to signal the SCC's clock input pins. The best-known such system was Centram's FlashTalk , which ran at 768 kbit/s, and was intended to be used with their TOPS networking system. A similar solution
1584-473: A single node within, a Token Ring system. Details of how this would work were sketchy. Just prior to its release in early 1985, AppleBus was renamed AppleTalk . Initially marketed as AppleTalk Personal Network , it comprised a family of network protocols and a physical layer. The physical layer had a number of limitations, including a speed of only 230.4 kbit/s, a maximum distance of 1,000 feet (300 m) from end to end, and only 32 nodes per LAN. But as
1672-418: A single organization gives the owner the ability to place restrictions on the use of the protocol and to change the protocol unilaterally. Specifications for proprietary protocols may or may not be published, and implementations are not freely distributed . Proprietors may enforce restrictions through control of the intellectual property rights, for example through enforcement of patent rights, and by keeping
1760-495: A single port on the back of the computer into which the user could plug an adaptor for any given cabling system. This FriendlyNet system was based on the industry-standard Attachment Unit Interface or AUI, but deliberately chose a non-standard connector that was smaller and easier to use, which they called "Apple AUI", or AAUI . FriendlyNet was first introduced on the Quadra 700 and Quadra 900 computers, and used across much of
1848-440: A solution, EtherTalk was initially created to use the Ethernet as a backbone between LocalTalk subnets. To accomplish this, organizations would need to purchase a LocalTalk-to-Ethernet bridge and Apple left it to third parties to produce these products. A number of companies responded, including Hayes and a few newly formed companies like Kinetics. By 1987, Ethernet was clearly winning the standards battle over Token Ring, and in
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#17327808726941936-503: A timeout elapsed. This way, it could respond to duplicate requests with the same transaction ID by resending the same response data, without performing the actual operation again. The Datagram Delivery Protocol (DDP) was the lowest-level data-link-independent transport protocol. It provided a datagram service with no guarantees of delivery. All application-level protocols, including the infrastructure protocols NBP, RTMP and ZIP, were built on top of DDP. AppleTalk's DDP corresponds closely to
2024-544: A unifying warm gray color they called Platinum across its entire product line, which was to last for over a decade. The LaserWriter was also the first peripheral to use the LocalTalk connector and Apple's unified round AppleTalk Connector Family, which allowed any variety of mechanical networking systems to be plugged into the ports on the computers or printers. A common solution was the 3rd party PhoneNET which used conventional telephone cables for networking. Apple's RIP
2112-497: Is designed to replace TCP transparently in order to overcome perceived inefficiencies related to wireless data transport. Microsoft Exchange Server protocols are proprietary open access protocols. The rights to develop and release protocols are held by Microsoft, but all technical details are free for access and implementation. Microsoft developed a proprietary extension to the Kerberos network authentication protocol for
2200-399: Is provided, one is picked at random from the "base subnet", 0. It then broadcasts another packet saying "I am selecting this address", and then waits to see if anyone else on the network complains. If another machine has that address, the newly connecting machine will pick another address, and keep trying until it finds a free one. On a network with many machines it may take several tries before
2288-592: Is the process of retrieving a protocol’s details from a software implementation of the specification. Methods of reverse-engineering a protocol include packet sniffing and binary decompilation and disassembly . There are legal precedents when the reverse-engineering is aimed at interoperability of protocols. In the United States , the Digital Millennium Copyright Act grants a safe harbor to reverse engineer software for
2376-575: The AppleTalk protocol stack , LocalTalk connected the LaserWriter to the Mac over an RS-422 serial port. At 230.4 kbit / s LocalTalk was slower than the Centronics PC parallel interface, but allowed several computers to share a single LaserWriter. PostScript enabled the LaserWriter to print complex pages containing high-resolution bitmap graphics , outline fonts , and vector illustrations. The LaserWriter could print more complex layouts than
2464-473: The HP LaserJet and other non-Postscript printers. Paired with the program Aldus PageMaker , the LaserWriter gave the layout editor an exact replica of the printed page. The LaserWriter offered a generally faithful proofing tool for preparing documents for quantity publication, and could print smaller quantities directly. The Mac platform quickly gained the favor of the emerging desktop-publishing industry,
2552-454: The IBM PC , EtherTalk for Apple's A/UX operating system allowing it to use LaserWriters and other network resources, and the Mac X.25 and MacX products. Ethernet had become almost universal by 1990, and it was time to build Ethernet into Macs direct from the factory. However, the physical wiring used by these networks was not yet completely standardized. Apple solved this problem using
2640-566: The Name Binding Protocol ( NBP ) was a dynamic system for mapping network addresses to user-readable names. Although systems similar to AARP existed in other systems, Banyan VINES for instance. Beginning about 2002 Rendezvous (the combination of DNS-based service discovery , Multicast DNS , and link-local addressing ) provided capabilities and usability using IP that were similar to those of AppleTalk. Both AARP and NBP had defined ways to allow "controller" devices to override
2728-667: The OSI model of protocol layering. Unlike most of the early LAN systems, AppleTalk was not built using the archetypal Xerox XNS system. The intended target was not Ethernet, and it did not have 48-bit addresses to route. Nevertheless, many portions of the AppleTalk system have direct analogs in XNS. One key differentiation for AppleTalk was it contained two protocols aimed at making the system completely self-configuring. The AppleTalk address resolution protocol ( AARP ) allowed AppleTalk hosts to automatically generate their own network addresses, and
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2816-691: The Power Macintosh G3 and PowerBook G3 . From the beginning of AppleTalk, users wanted to connect the Macintosh to TCP/IP network environments. In 1984, Bill Croft at Stanford University pioneered the development of IP packets encapsulated in DDP as part of the SEAGATE (Stanford Ethernet–AppleTalk Gateway) project. SEAGATE was commercialized by Kinetics in their LocalTalk-to-Ethernet bridge as an additional routing option. A few years later, MacIP
2904-578: The Windows 2000 operating system . The extensions made the protocol incompatible with implementations supporting the original standards, and this has raised concerns that this, along with the licensing restrictions, effectively denies products unable to conform to the standard access to a Windows 2000 Server using Kerberos. The use of proprietary instant messaging protocols meant that instant messaging networks were incompatible and people were unable to reach friends on other networks. Reverse engineering
2992-425: The "frame buffer", for the lowest resolution devices, 300 dpi), as more than 300 dpi of course required more RAM, and some LaserWriters were able to change between 300 dpi and 600 dpi, depending upon how much RAM was installed. 600 dpi, for example, required 6 MB of RAM, but 8 MB of RAM was more commonly found. At this point, Apple's LaserWriters were employing generic non-parity RAM, whereas HP's LaserJets, especially
3080-410: The AppleTalk cabling used a single common electrical ground , which limited speeds to about 500 kbit/s, but allowed one conductor to be removed. This meant that common three-conductor cables could be used for wiring. Additionally, the adaptors were designed to be "self-terminating", meaning that nodes at the end of the network could simply leave their last connector unconnected. There was no need for
3168-437: The AppleTalk model. The AppleTalk Address Resolution Protocol (AARP) resolves AppleTalk addresses to link layer addresses. It is functionally equivalent to ARP and obtains address resolution by a method very similar to ARP. AARP is a fairly simple system. When powered on, an AppleTalk machine broadcasts an AARP probe packet asking for a network address, intending to hear back from controllers such as routers. If no address
3256-434: The AppleTalk protocol itself. Apart from these, all application-level protocols were expected to use dynamically assigned socket numbers at both the client and server end. Because of this dynamism, users could not be expected to access services by specifying their address. Instead, all services had names which, being chosen by humans, could be expected to be meaningful to users, and also could be sufficiently long to minimize
3344-543: The LBP-CX, a desktop laser printer engine using a laser diode and featuring an output resolution of 300 dpi. In 1984, HP released the first commercially available system based on the LBP-CX, the HP LaserJet . Steve Jobs of Apple Computer had seen the LBP-CX while negotiating for supplies of 3.5" floppy disk drives for the upcoming Apple Macintosh computer. Meanwhile, John Warnock had left Xerox to found Adobe Systems to commercialize PostScript and AppleTalk in
3432-547: The LaserWriter II was designed to allow for complete replacement of the computer circuit board that operates the printer. Across all the different models, the print engine was the same. Three years later in 1991, two updated versions of the LaserWriter II were produced. To deliver higher performance, Apple eventually switched from the 68000 series to the Am29000 series of processors to drive later models, starting with
3520-501: The LaserWriter was a key component at the beginning of the desktop publishing revolution. Laser printing traces its history to efforts by Gary Starkweather at Xerox in 1969, which resulted in a commercial system called the Xerox 9700 . IBM followed this with the IBM 3800 system in 1976. Both machines were large, room-filling devices handling the combined output of many users. During
3608-469: The LaserWriter, PostScript, PageMaker and the Mac's GUI and built-in AppleTalk networking would ultimately transform the landscape of computer desktop publishing. At the time, Apple planned to release a suite of AppleTalk products as part of the Macintosh Office , with the LaserWriter being only the first component. While competing printers and their associated control languages offered some of
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3696-452: The Mac line for some time. As with LocalTalk, a number of third-party FriendlyNet adaptors quickly appeared. As 10BASE-T became the de facto cabling system for Ethernet, second-generation Power Macintosh machines added a 10BASE-T port in addition to AAUI. The PowerBook 3400c and lower-end Power Macs also added 10BASE-T. The Power Macintosh 7300 / 8600 / 9600 were the final Macs to include AAUI, and 10BASE-T became universal starting with
3784-509: The Mac, LaserWriter, and a file server system which would become the Macintosh Office . By late 1983 it was clear that IBM's Token Ring would not be ready in time for the launch of the Mac, and might miss the launch of these other products as well. In the end, Token Ring would not ship until October 1985. Jobs' earlier question to Sidhu had already sparked a number of ideas. When AppleNet was cancelled in October, Sidhu led an effort to develop
3872-488: The Macintosh HFS filesystem. AFP is still in use in macOS, even though most other AppleTalk protocols have been deprecated. The AppleTalk Session Protocol (ASP) was an intermediate protocol, built on top of AppleTalk Transaction Protocol (ATP), which in turn was the foundation of AFP. It provided basic services for requesting responses to arbitrary commands and performing out-of-band status queries. It also allowed
3960-536: The NCSA packages, especially NCSA Mosaic and its offspring, Netscape Navigator . Additionally, a number of server products appeared that allowed the Mac to host Internet content. Through this period, Macs had about 2 to 3 times as many clients connected to the Internet as any other platform, despite the relatively small overall microcomputer market share. As the world quickly moved to IP for both LAN and WAN uses, Apple
4048-548: The Network layer of the Open Systems Interconnection ( OSI ) communication model. The Name Binding Protocol (NBP) was a dynamic, distributed system for managing AppleTalk names. When a service started up on a machine, it registered a name for itself as chosen by a human administrator. At this point, NBP provided a system for checking that no other machine had already registered the same name. Later, when
4136-490: The adaptor into the machine, then connected a cable from it to any free port on any other adaptor. The AppleTalk network stack negotiated a network address, assigned the computer a human-readable name, and compiled a list of the names and types of other machines on the network so the user could browse the devices through the Chooser . AppleTalk was so easy to use that ad hoc networks tended to appear whenever multiple Macs were in
4224-502: The addition of downloadable bitmapped fonts. It lacked the power and flexibility of PostScript until several upgrades provided some level of parity. It was some time before similar products became available on other platforms, by which time the Mac had ridden the desktop publishing market to success. The LaserWriter used the same Canon CX printing engine as the HP LaserJet, and as a consequence early LaserWriters and LaserJets shared
4312-437: The basic hardware was built into the Mac, adding nodes only cost about $ 50 for the adaptor box. In comparison, Ethernet or Token Ring cards cost hundreds or thousands of dollars. Additionally, the entire networking stack required only about 6 kB of RAM, allowing it to run on any Mac. The relatively slow speed of AppleTalk allowed further reductions in cost. Instead of using RS-422 's balanced transmit and receive circuits,
4400-490: The capabilities of PostScript, they were limited in their ability to reproduce free-form layouts (as a desktop publishing application might produce), use outline fonts , or offer the level of detail and control over the page layout. HP's own LaserJet was driven by a simple page description language , known as Printer Command Language , or PCL. The version for the LaserJet, PCL4, was adapted from earlier inkjet printers with
4488-453: The chance of conflicts. As NBP names translated to an address, which included a socket number as well as a node number, a name in AppleTalk mapped directly to a service being provided by a machine, which was entirely separate from the name of the machine itself. Thus, services could be moved to a different machine and, so long as they kept the same service name, there was no need for users to do anything different in order to continue accessing
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#17327808726944576-440: The default mechanisms. The concept was to allow routers to provide the information or "hardwire" the system to known addresses and names. On larger networks where AARP could cause problems as new nodes searched for free addresses, the addition of a router could reduce "chattiness." Together AARP and NBP made AppleTalk an easy-to-use networking system. New machines were added to the network by plugging them in and optionally giving them
4664-540: The end of 1987, 130,000 such networks were in use. AppleTalk was at that time the most used networking system in the world, with over three times the installations of any other vendor. 1987 also marked the introduction of the AppleShare product, a dedicated file server that ran on any Mac with 512 kB of RAM or more. A common AppleShare machine was the Mac Plus with an external SCSI hard drive . AppleShare
4752-517: The entire "frame" could be contained within the available RAM ). In most cases, such RAM was fixed in size and was soldered to the logic board. In late PostScript Level 1, and in early PostScript Level 2, the RAM size was made variable and was generally extensible, through plug-in DIMMs, beyond the 2.0 to 2.5 MB minimum (0.5 to 1.0 MB for instructions, depending upon PostScript version, and 1.5 MB minimum for
4840-517: The low-level protocols were on their way to completion. Sidhu mentioned the work to Belleville only two hours after the Mac was announced. The "new" AppleBus was announced in early 1984, allowing direct connection from the Mac or Lisa through a small box that is plugged into the serial port and connected via cables to the next computer upstream and downstream. Adaptors for Apple II and Apple III were also announced. Apple also announced that an AppleBus network could be attached to, and would appear to be
4928-399: The mid-1970s, Canon started working on similar machines, and partnered with Hewlett-Packard to produce 1980's HP 2680, which filled only part of a room. Other copier companies also started development of similar systems. HP introduced their first desktop model with a Ricoh engine for $ 12,800 in 1983. Sales of the non-networked product were unsurprisingly poor. In 1983, Canon introduced
5016-641: The middle of that year, Apple introduced EtherTalk 1.0 , an implementation of the AppleTalk protocol over the Ethernet physical layer. Introduced for the newly released Macintosh II computer, one of Apple's first two Macintoshes with expansion slots (the Macintosh SE had one slot of a different type), the operating system included a new Network control panel that allowed the user to select which physical connection to use for networking (from "Built-in" or "EtherTalk"). At introduction, Ethernet interface cards were available from 3Com and Kinetics that plugged into
5104-482: The most processing power in Apple's product line—more than the 8 MHz Macintosh. As a result, the LaserWriter was also one of Apple's most expensive offerings. For implementation purposes, the LaserWriter employed a small number of medium-scale-integration Monolithic Memories PALs , and no custom LSI , whereas the LaserJet employed a large number of small-scale-integration Texas Instruments 74-Series gates, and one custom LSI. The LaserWriter was, thereby, in
5192-429: The networking stack that often caused problems. As Apple expanded into more commercial and education markets, they needed to integrate AppleTalk into existing network installations. Many of these organisations had already invested in a very expensive Ethernet infrastructure and there was no direct way to connect a Macintosh to Ethernet. AppleTalk included a protocol structure for interconnecting AppleTalk subnets and so as
5280-596: The ones which offered a plug-in PostScript interpreter card, required special parity-type PS/2 RAM modules with a "presence detect" function according to IBM specs. Building on the success of the original LaserWriter, Apple developed many further models. Later LaserWriters offered faster printing, higher resolutions , Ethernet connectivity, and eventually color output in the Color LaserWriter . To compete, many other laser printer manufacturers licensed Adobe PostScript for inclusion into their own models. Eventually
5368-596: The problem of supporting IP on their many LocalTalk-equipped Macs. It was soon common to include MacIP support in LocalTalk-to-Ethernet bridges. MacTCP would not become a standard part of the Classic Mac OS until 1994, by which time it also supported SNMP and PPP . For some time in the early 1990s, the Mac was a primary client on the rapidly expanding Internet. Among the better-known programs in wide use were Fetch, Eudora, eXodus, NewsWatcher, and
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#17327808726945456-434: The protocol specification a trade secret . Some proprietary protocols strictly limit the right to create an implementation; others are widely implemented by entities that do not control the intellectual property but subject to restrictions the owner of the intellectual property may seek to impose. The Skype protocol is a proprietary protocol. The Venturi Transport Protocol (VTP) is a patented proprietary protocol that
5544-478: The purposes of interoperability with other software. LaserWriter The LaserWriter is a laser printer with built-in PostScript interpreter sold by Apple, Inc. from 1985 to 1988. It was one of the first laser printers available to the mass market. In combination with WYSIWYG publishing software like PageMaker that operated on top of the graphical user interface of Macintosh computers,
5632-567: The release of Mac OS X v10.6 in 2009. Many of AppleTalk's more advanced autoconfiguration features have since been introduced in Bonjour , while Universal Plug and Play serves similar needs. After the release of the Apple Lisa computer in January 1983, Apple invested considerable effort in the development of a local area networking (LAN) system for the machines. Known as AppleNet , it
5720-498: The same form factor (for its RIP ), able to provide much greater function, and, indeed, much greater performance, all within the very same LBP-CX form factor, although the external packaging was, for marketing purposes, somewhat different. Since the cost of a LaserWriter was several times that of a dot-matrix impact printer , some means to share the printer with several Macs was desired. LANs were complex and expensive, so Apple developed its own networking scheme, LocalTalk . Based on
5808-642: The same room. Apple would later use this in an advertisement showing a network being created between two seats in an airplane. A thriving third-party market for AppleTalk devices developed over the next few years. One particularly notable example was an alternate adaptor designed by BMUG and commercialised by Farallon as PhoneNET in 1987. This was essentially a replacement for Apple's connector that had conventional phone jacks instead of Apple's round connectors. PhoneNet allowed AppleTalk networks to be connected together using normal telephone wires, and with very little extra work, could run analog phones and AppleTalk on
5896-423: The same time, Jonathan Seybold ( John W. Seybold 's son) introduced Paul Brainerd to Apple, where he learned of Apple's laser printer efforts and saw the potential for a new program using the Mac's GUI to produce PostScript output for the new printer. Arranging his own funding through a venture capital firm, Brainerd formed Aldus and began development of what would become PageMaker . The venture capital coined
5984-407: The same time-frame as Apple's LaserWriter, Adobe was licensing the very same version of PostScript to Apple's potential competitors (Apple's PostScript licensing terms were non-exclusive); however, all non-Apple licensees of PostScript generally employed one of Adobe's PostScript "reference models" (Atlas, Redstone, etc.) and even Linotype 's first image setter which featured PostScript employed such
6072-405: The same toner cartridges and paper trays. PostScript is a complete programming language that has to be run in a suitable interpreter and then sent to a software rasterizer program, all inside the printer. To support this, the LaserWriter featured a Motorola 68000 CPU running at 12 MHz , 512 KB of workspace RAM , and a 1 MB frame buffer. At introduction, the LaserWriter had
6160-621: The server to send asynchronous attention messages to the client. The AppleTalk Transaction Protocol (ATP) was the original reliable transport-level protocol for AppleTalk, built on top of DDP. At the time it was being developed, a full, reliable connection-oriented protocol like TCP was considered to be too expensive to implement for most of the intended uses of AppleTalk. Thus, ATP was a simple request/response exchange, with no need to set up or tear down connections. An ATP request packet could be answered by up to eight response packets. The requestor then sent an acknowledgement packet containing
6248-409: The service is moved to a different machine. This can be mitigated somewhat by insistence on using CNAME records indicating service rather than actual machine names to refer to the service, but there is no way of guaranteeing that users will follow such a convention. Some newer protocols, such as Kerberos and Active Directory use DNS SRV records to identify services by name, which is much closer to
6336-478: The service. And the same machine could host any number of instances of services of the same type, without any network connection conflicts. Contrast this with A records in the DNS , in which a name translates to a machine's address, not including the port number that might be providing a service. Thus, if people are accustomed to using a particular machine name to access a particular service, their access will break when
6424-415: The standardization on Ethernet for connectivity and the ubiquity of PostScript undermined the unique position of Apple's printers: Macintosh computers functioned equally well with any Postscript printer. After the LaserWriter 8500, Apple discontinued the LaserWriter product line in 1997 when Steve Jobs returned to Apple. In 1988, to address the need for both an affordable printer and a professional printer,
6512-635: The term "desktop publishing" during this time. The LaserWriter was announced at Apple's annual shareholder meeting on January 23, 1985, the same day Aldus announced PageMaker. Shipments began in March 1985 at the retail price of US$ 6,995, significantly more than the HP model. However, the LaserWriter featured AppleTalk support that allowed the printer to be shared among as many as sixteen Macs, meaning that its per-user price could fall to under $ 450, far less expensive than HP's less-advanced model. The combination of
6600-449: The wires to be connected back together into a loop, nor the need for hubs or other devices. The system was designed for future expansion; the addressing system allowed for expansion to 255 nodes in a LAN (although only 32 could be used at that time), and by using "bridges" (which came to be known as "routers", although technically not the same) one could interconnect LANs into larger collections. "Zones" allowed devices to be addressed within
6688-662: Was a topic of major commercial effort at the time, dominating shows like the National Computer Conference (NCC) in Anaheim in May 1983. All of the systems were jockeying for position in the market, but even at this time, Ethernet's widespread acceptance suggested it was to become a de facto standard. It was at this show that Steve Jobs asked Gursharan Sidhu a seemingly innocuous question: "Why has networking not caught on?" Four months later, in October, AppleNet
6776-602: Was based on the seminal Xerox XNS protocol stack but running on a custom 1 Mbit/s coaxial cable system rather than Xerox's 2.94 Mbit/s Ethernet . AppleNet was announced early in 1983 with a full introduction at the target price of $ 500 for plug-in AppleNet cards for the Lisa and the Apple II . At that time, early LAN systems were just coming to market, including Ethernet , Token Ring , Econet , and ARCNET . This
6864-412: Was cancelled. At the time, they announced that "Apple realized that it's not in the business to create a networking system. We built and used AppleNet in-house, but we realized that if we had shipped it, we would have seen new standards coming up." In January, Jobs announced that they would instead be supporting IBM 's Token Ring, which he expected to come out in a "few months". Through this period, Apple
6952-464: Was deep in development of the Macintosh computer. During development, engineers had made the decision to use the Zilog 8530 serial controller chip (SCC) instead of the lower-cost and more common UART to provide serial port connections. The SCC cost about $ 5 more than a UART, but offered much higher speeds of up to 250 kilobits per second (or higher with additional hardware) and internally supported
7040-577: Was deep in their ultimately doomed Copland efforts. With the purchase of NeXT and subsequent development of Mac OS X , AppleTalk was strictly a legacy system. Support was added to Mac OS X in order to provide support for a large number of existing AppleTalk devices, notably laser printers and file shares, but alternate connection solutions common in this era, notably USB for printers, limited their demand. As Apple abandoned many of these product categories, and all new systems were based on IP, AppleTalk became less and less common. AppleTalk support
7128-577: Was faced with maintaining two increasingly outdated code bases on an ever-wider group of machines as well as the introduction of the PowerPC -based machines. This led to the Open Transport efforts, which re-implemented both MacTCP and AppleTalk on an entirely new code base adapted from the Unix standard STREAMS . Early versions had problems and did not become stable for some time. By that point, Apple
7216-685: Was finally removed from the macOS line in Mac OS X v10.6 in 2009. However, the loss of AppleTalk did not reduce the desire for networking solutions that combined its ease of use with IP routing. Apple has led the development of many such efforts, from the introduction of the AirPort router to the development of the zero-configuration networking system and their implementation of it, Rendezvous, later renamed Bonjour . As of 2020, AppleTalk support has been completely removed from legacy support with macOS 11 Big Sur. The AppleTalk design rigorously followed
7304-506: Was known as AppleBus , envisioning a system controlled by the host Macintosh polling "dumb" devices in a fashion similar to the modern Universal Serial Bus . The Macintosh team had already begun work on what would become the LaserWriter and had considered a number of other options to answer the question of how to share these expensive machines and other resources. A series of memos from Bob Belleville clarified these concepts, outlining
7392-443: Was of its own design, and was implemented using few ICs, including PALs for most combinatorial logic; with the subsystem timing DRAM refreshing, and rasterization functions being implemented in very few medium-scale-integration PALs. Apple's competitors (i.e., QMS , NEC , and others) generally used a variation of one of Adobe's RIPs with their large quantity of small-scale-integration (i.e., Texas Instruments ' 7400 series) ICs. In
7480-541: Was released in 1985 and was the primary protocol used by Apple devices through the 1980s and 1990s. Versions were also released for the IBM PC and compatibles and the Apple IIGS . AppleTalk support was also available in most networked printers (especially laser printers ), some file servers , and a number of routers . The rise of TCP/IP during the 1990s led to a reimplementation of most of these types of support on that protocol, and AppleTalk became unsupported as of
7568-541: Was separated from the SEAGATE code and became the de facto method for IP packets to be routed over LocalTalk networks. By 1986, Columbia University released the first version of the Columbia AppleTalk Package (CAP) that allowed higher integration of Unix, TCP/IP, and AppleTalk environments. In 1988, Apple released MacTCP , a system that allowed the Mac to support TCP/IP on machines with suitable Ethernet hardware. However, this left many universities with
7656-638: Was the #3 network operating system in the late 1980s, behind Novell NetWare and Microsoft's MS-Net . AppleShare was effectively the replacement for the failed Macintosh Office efforts, which had been based on a dedicated file server device. A significant re-design was released in 1989 as AppleTalk Phase II . In many ways, Phase II can be considered an effort to make the earlier version (never called Phase I) more generic. LANs could now support more than 255 nodes, and zones were no longer associated with physical networks but were entirely virtual constructs used simply to organize nodes. For instance, one could now make
7744-426: Was the 850 kbit/s DaynaTalk , which used a separate box that plugged in between the computer and a normal LocalTalk/PhoneNet box. Dayna also offered a PC expansion card that ran up to 1.7 Mbit/s when talking to other Dayna PC cards. Several other systems also existed with even higher performance, but these often required special cabling that was incompatible with LocalTalk/PhoneNet, and also required patches to
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