PhoneNET

PhoneNET is a discontinued implementation of the AppleTalk networking physical layer created by the Berkeley Macintosh Users Group (BMUG) and commercialized by Farallon Computing (now Netopia). It used conventional four-conductor telephone Category 1 patch cords and RJ-11 modular connectors in place of Apple's more complex cabling system. It was far more popular than Apple's implementation before the widespread implementation of Ethernet.

Description

When Apple introduced AppleTalk in 1985, they used a propietary connector and cabling system based on shielded twisted pair 4-conductor cables with three-pin mini-DIN connectors connecting to the computer using an external dongle plugged into one of the Macintosh's RS-422 ports. The dongles included terminating resistors that allowed the network to be connected together without having to know where the ends were. Originally known as "AppleTalk Personal Network", the system was later renamed LocalTalk.

Later the same year, Reese M. Jones of the Berkeley Macintosh Users Group created an alternative dongle that connected together using conventional telephone cabling with RJ-11 connectors. The dongles were not self-terminating, but as a result, they were also less complex. Connecting together a network using these "BMUGnet" was much less expensive than using Apple's system and could often be accomplished using existing telephone wiring already installed in buildings. Jones filed a patent on the system in August 1986.^[1]

Jones assigned the patent to Farallon, who introduced the product as PhoneNet. This was later supplanted, and then replaced, by PhoneNet Plus, which switched from the original Macintosh's DE-9 serial port connection to the Macintosh Plus' new Mini-DIN 8, which remained in use until the Power Macintosh G3 systems. Farallon also introduced the PhoneNET StarController, available in 12 and 24-port versions, which isolated traffic between nodes to improve performance. Later versions of the PhoneNet adaptors featured modified cases to match the case style of the StarControllers.

Like LocalTalk, the maximum speed for data transfer was 230 kbit/s unless accelerating drivers were used to override the operating system's drivers. Unlike LocalTalk, which only supported a daisy chain topology, PhoneNET was principally used in star topologies over structured cabling plants.

Functionality

Farallon PhoneNET and Apple LocalTalk transceivers. Both connected computing devices (like Macintoshes and LaserWriter printers) with Serial ports to LocalTalk local area networks. The Farallon transceiver did so over ANSI/TIA-568 standard structured cabling plants, while the Apple transceiver used a short-range proprietary daisy chain.

Unlike LocalTalk's four-wire grounded implementation, PhoneNET used a single twisted pair, or the outside two wires of a four-conductor flat cable.

As normal telephone equipment used the inside two wires, PhoneNET could share cabling with telephones, allowing both phone calls and networking over a single cable.

Superseded by

Though PhoneNET transceivers are still available from third parties for use on legacy Macintosh networks, no Apple computer or device has been made with the RS-422 mini-DIN-8 serial ports required for LocalTalk networking since the discontinuation of the Power Macintosh G3 in 1999.^{[citation needed]}

As of 2023^[update], Apple devices use Ethernet or wireless networking.^{[citation needed]}

References

^ US expired 5003579A, Reese M. Jones, "System for connecting computers via telephone lines"

External links

PhoneNET User's Guide: Scribd - Internet Archive
Schematics
Photos

[1] US expired 5003579A, Reese M. Jones, "System for connecting computers via telephone lines"

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