Duo Dock

The Macintosh Duo Dock is the original full-size docking station that was developed by Apple Computer and released on October 19, 1992, along with the PowerBook Duo 210 and 230. It was superseded on May 16, 1994 by the Duo Dock II. Both of the preceding full-size docks were replaced by the Duo Dock Plus, which was released on May 15, 1995.

Features
The Duo Dock features a large front-facing slot through which a PowerBook Duo notebook could be inserted. A motor would draw it into a custom 152-pin docking connector. All the ports, drives, and expansion slots of the dock would become accessible by the PowerBook Duo as a NuBus device. A FPU socket can accept an optional Motorola 68882 co-processor to provide support to 68030 processors. 512KB of video RAM on the logic board can support up to 8-bit color on a 832 x 624 display. A VRAM slot allows it to be upgraded to 1MB to support 16-bit color. A 3.5-inch drive bay can accept an optional SCSI drive. The back of the dock also included a small pop-out panel to make space for an Ethernet port through a logic board upgrade (to a Duo Dock II or Plus).

The PowerBook Duo can be ejected by pressing a button at the right. A keylock named PowerLatch allows it to be secured to prevent unauthorized ejection.

Development
The Duo Dock was approved for by the  on October 9, 1992.

Supported models
The first Duo Dock was released when the PowerBook Duo lineup only consisted of models with grayscale displays; it also supported subsequent models with grayscale displays.
 * PowerBook Duo 210 (25 MHz 68030)
 * PowerBook Duo 230 (33 MHz 68030)
 * PowerBook Duo 250 (33 MHz 68030)
 * PowerBook Duo 280 (66/33 MHz 68LC040)

Models requiring an upgrade
Newer Duo models with color displays were about 2mm thicker than grayscale models, which required replacement of the original top cover with a slightly taller version which also included a front door to keep out dust (like the Duo Dock II and Plus).
 * PowerBook Duo 270c (33 MHz 68030)
 * PowerBook Duo 280c (66/33 MHz 68LC040)
 * PowerBook Duo 2300c (100 MHz PowerPC 601)

Issues
As Duo Docks age, capacitors which drive the docking mechanism are known to fail, resulting in a "Tick of Death" and requiring replacement.