Local Talk

When Apple introduced its expensive LaserWriter printer in the mid-1980s, it needed some way to network the printer so that small offices could justify the printer's high price. The result was a protocol called AppleTalk. That name originally applied to both the hardware and the software, but eventually the hardware acquired its own name: LocalTalk. Nonetheless, there are still occasional references to the hardware by the name AppleTalk.

By today's standards, LocalTalk is quite primitive and slow. Its maximum speed is 2Mbps— one-fifth the speed of 10Mbps Ethernet, and one-fiftieth (1/50) the speed of modern 100Mbps Ethernet. The original LocalTalk cabling was a proprietary design and limited in length to 1,000 feet in a bus topology (described shortly). Although LocalTalk is an Apple technology, another company, Farallon, introduced a product called PhoneNET that allows LocalTalk to traverse ordinary telephone wires. PhoneNet also extends LocalTalk's cabling range to 3,000 feet.

Part IV

Because of its very low speed, I don't recommend using LocalTalk unless you must. If you must connect a Linux computer to a LocalTalk network, you might be able to get it to work in one of two ways:

• Linux LocalTalk support The Linux kernel includes support for two x86 LocalTalk boards, in the Network device support, Appletalk devices kernel configuration menu. These boards are difficult to find, though, and LocalTalk networks frequently aren' t configured for the protocols used on the Internet as a whole.

• LocalTalk/Ethernet bridges Separate hardware products exist to link LocalTalk and Ethernet networks. For instance, the Asante (http://www.asante.com) AsanteTalk lets you connect eight LocalTalk devices to an Ethernet network.

LocalTalk poses an additional challenge to Linux: It's almost always used with the AppleTalk file- and printer-sharing protocols. Most Linux networking occurs through the Transmission Control Protocol/Internet Protocol (TCP/IP) networking stack, but AppleTalk uses a separate stack. The Netatalk program (http://www.umich.edu/-rsug/netatalk/) allows Linux to use the AppleTalk protocols to serve files or printers on a Linux computer to Macintoshes, or to print to Macintosh printers using AppleTalk protocols. (You can read more about using Netatalk in my book, Linux: Networking for Your Office, Sams Publishing, 2000.)


The AppleTalk protocols aren't limited to LocalTalk networks. Recent Macintoshes no longer include LocalTalk support; instead, they include Ethernet adapters. These Macintoshes use AppleTalk over Ethernet. You can safely mix Macintoshes and x86 PCs on the same network; the AppleTalk and TCP/IP networking stacks don't interfere with one another.

Continue reading here: Exotic Adapters

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