Duo Dock II

The PowerBook Duo Dock II is a full-size docking station that was developed by Apple Computer and released on May 16, 1994, along with the PowerBook Duo 280 and 280c. It superseded the original Duo Dock and was replaced on May 15, 1995 by the Duo Dock Plus.

Features
Like the original Duo Dock, the Duo Dock II 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 3.5-inch drive bay can accept an optional SCSI drive.

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.

Updates
The Duo Dock II featured a revised top cover that was 2mm taller to accommodate newer PowerBook Duo models with thicker color displays. A front door was added to keep out dust. A new AAUI-15 connector allowed the attachment of Ethernet dongles. The on-board video RAM was increased to 1MB to support up to 16-bit color on a 832 x 624 display. It also includes 32KB of L2 cache and a Motorola 68882 co-processor to provide support to 68030 processors. However, the L2 cache and floating-point unit are not supported by models with 68LC040 or PowerPC processors.

Supported models

 * PowerBook Duo 210 (25Mhz 68030)
 * PowerBook Duo 230 (33Mhz 68030)
 * PowerBook Duo 250 (33Mhz 68030)
 * PowerBook Duo 270c (33Mhz 68030)
 * PowerBook Duo 280 (33Mhz 68LC040)
 * PowerBook Duo 280c (33Mhz 68LC040)
 * PowerBook Duo 2300c (100Mhz 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.