Bridging LocalTalk and Ethernet
There are two kinds of wiring typically used on the Macintosh: LocalTalk and ethernet (see LocalTalk and Ethernet for more details).
LocalTalk is usually run on phone wire using Farallon PhoneNet adapters or a generic equivalent. Speed is about 1/4Mbps. LocalTalk has been built into every Mac since the 1986 Mac Plus - until the iMac.
Beginning in the Quadra era, Apple began installing ethernet ports as standard features. Today, every Macintosh made has ethernet. Regular ethernet can reach 10Mbps (40 times the speed of LocalTalk), and the newer 100Base-T ethernet is ten times faster.
The Macintosh can communicate over both types of cable using AppleTalk, the network protocol Apple invented in the Mac's infancy. Macs with ethernet can also use the TCP/IP protocol, which is the protocol of the internet.
It's not uncommon to see Mac networks at home, at school, and in the office. LocalTalk made it both easy and inexpensive, especially after Farallon created PhoneNet. And today, 10Base-T ethernet isn't particularly expensive, making it the norm for networking.
But there's a problem when you need to put both a new iMac or Blue and White Power Mac G3 and an old LaserWriter or Mac Plus on the same network. The newest Macs are ethernet only. The older Macs, LocalTalk only.
How you solve the problem depends on how much equipment of the one type you need to connect to a network of the other type. In larger installations, you may end up with both a LocalTalk network and an ethernet network with a bridge between them.
If all your hardware uses ethernet, but you need to run an old LocalTalk printer (older LaserWriters, StyleWriter 4000 series, HP DeskWriters, etc.) or connect to some old Macs, the easy solution is a simple Ethernet-to-LocalTalk adapter.
Thanks to the ethernet-only iMac, such adapters have recently become popular again. The Farallon iPrint, Asante AsanteTalk, and Asante Micro AsantePrint adapters bridge up to 8 LocalTalk devices to an ethernet network at a very affordable price.
If you need more LocalTalk devices, you could use more than one bridge or try to locate an old Farallon StarRouter. This very expensive device had a dozen switched LocalTalk ports, each of which could easily support four devices. The StarRouter has another advantage as well: it can act as a MacIP gateway, giving LocalTalk only Macs access to the internet.
Another hardware solution is the SCSI-to-ethernet adapter, a device that connects to the SCSI port on the Macintosh and puts it on an ethernet network. For a single older Mac, this can be less expensive than the Farallon and Asante bridges mentioned above.
Farallon has a unique solution that provides a faster connection than the LocalTalk-to-ethernet bridge: EtherMac and EtherWave adapters. By clocking the LocalTalk port at a higher than usual speed (something even the first Macintosh allowed), these adapter let your Mac communicate over ethernet at about 3x the speed of LocalTalk. An added advantage of the EtherWave adapter is a pass-through port for daisy chaining ethernet devices. Drawbacks include price (compared to a bridge) and no support for OpenTransport.
The final hardware solution: an ethernet card. It is possible to find used NuBus ethernet cards for under $30, which will connect any Mac with a free NuBus slot to ethernet at full speed. If you search, you can even find ethernet cards for the LC processor direct slot, the ancient Macintosh SE, the 030 PDS in the SE/30 and IIsi, and the processor direct slot in the Centris 610.
But for most PowerBooks, the Mac Plus, and a lot of single-slot Macs that have accelerators, an ethernet card is not an option.
Since originally writing this, the following hardware has been recommended by readers:
- Farallon InterRoute/5
- Shiva FastPath 4 & FastPath 5
- Cayman Gatorbox
- Dayna Pathfinder (Appletalk only)
I don't have any experience with these, but pass them along as further suggestions.
Apple has two software solutions, the LaserWriter Bridge and LocalTalk Bridge. Each must be run on a Macintosh.
LaserWriter Bridge is specifically for connecting a single printer to an ethernet network via a Macintosh hose. A recent search of Apple's site didn't turn up a copy of LaserWriter Bridge, which Apple made freely available some time ago. However, everything LW Bridge could do, LocalTalk Bridge can also do.
LocalTalk Bridge is a control panel (no longer supported by Apple, but apparently available for free download) that connects a LocalTalk network to an ethernet network. The host computer should be active as a bridge before any LocalTalk printers are turned on or any time any devices need to communicate between the LocalTalk and ethernet networks.
Except for the Farallon StarRouter, none of the bridge solutions allow use of TCP/IP, which means the oldest Macs can't access the internet.
Of the other products, the Farallon EtherMac and EtherWave adapters will allow TCP/IP connection, although only using Classic Networking. (They do no support OpenTransport.) The SCSI-to-ethernet adapters and network cards also support TCP/IP, which can make them attractive.
A future article will look at ways to connect LocalTalk devices to the internet via your network.
Next: Sharing an internet connection
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