Some third party solutions are listed below. To create your own cable you will have to take into consideration the electrical characteristics of the cable and signal, so you may wish to consult with an electrical engineer. If you attempt to build a 100 foot ADB cable, you will have resistance you need to overcome with line drivers or repeaters; you will also have noise, resonance and ringing to deal with, in addition to floating signals (in relationship to ground). Connecting multiple ADB devices compounds these difficulties.

Many of the ADB electrical requirements and characteristics are documented in the Guide to The Macintosh Family Hardware Reference Manual.

Though we do not have a "recipe" for extending an ADB cable beyond our specifications, hopefully this response will give you some issues to consider as well as inform you about existing third party solutions.

Kensington Microware, Ltd. sells an Extra Long ADB Keyboard Cable. It is an 8-foot replacement cable, 4-feet longer than the standard Macintosh cable.

Smart Remote, from Sayett, is a wireless, infrared programmable remote control, which can control Macintosh programs up to 35 feet away from the computer. To operate, connect the remote receiver to the ADB bus, and users are ready to use the preset commands, such as forward, inverse and screen blank, which are common to most presentations software. The Smart Remote performs mouse functions and cursor movement, and can be programmed to meet most presentation and training needs.

Display Research Laboratory sells the MR Remote. It includes HyperCard externals and a sample stack. MR Remote is an ADB device for infrared remote control of audio-video equipment, such as TVs, VCRs, LD players, camcorders and. With this product, users no longer need to use equipment with a special computer interface. Instead, they can use a consumer product of their choice, or the one they already have. Users can control the equipment in HyperCard, SuperCard or MacroMind Director. Externals and a sample HyperCard stack for most brands of VCRs and TVs are included.

Switch-Back, from Madenta Communications, Inc., is a powerful interface that enables unique control of the Macintosh computer by any simple switch. When a switch is pressed, Switch-Back makes the Macintosh think a function key on the keyboard was pressed. Desired software tasks may be assigned to the function keys F10 through F15 (for switch 1 through switch 6). Pressing the switch will invoke that task. Any macro program is compatible with Switch-Back. Switch-Back may be connected anywhere on the ADB and accepts input from up to six switches. These switches are plugged into a trio of 3.5mm stereo jacks at the rear of the unit. Other features include: turn on any computer in the Macintosh II family remotely with any push button switch; small, sleek design; FCC Class B certified; switch cable length allowed up to 5,500 feet; and 36 pin Centronics connector for future expansion.

Mac Extend, from Presentation Electronics, Inc., connects to the Macintosh, keyboard and mouse, and to a remote unit up to 1,000-feet away. Mac Extend connects to the Macintosh computer's ADB port, keyboard and mouse, and to a remote unit up to 1,000-feet away via a standard RS-232 cable. The remote unit provides a standard ADB port for a second keyboard, mouse or other ADB device. The system is ideal for presentations, training, multimedia applications and more, where access to a Macintosh at the podium is required, yet the computer must be located at a remote location, such as at a video projector.

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06 Jan 1995 - Reviewed and updated.

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