Controllers, Cables, Packaging

This interoffice memorandum, dated October 15, 1973, from Roger Cady to DEC leadership, proposes a redesign of hardware packaging and cabling to improve reliability, serviceability, and manufacturing costs for the PDP-11 line. Key recommendations include:

• Standardized Backpanels: Expanding to 20 slots, using multilayer PCBs for impedance control, and adopting standardized mounting to simplify access and improve testing.
• Peripheral Cables: Improving connector reliability with strain relief and locking mechanisms, and drastically reducing the number of cable types through standardization.
• Controller Density: Implementing Large Scale Integration (LSI) to reduce chip count and utilizing a hinged, multi-board module concept for complex controllers that exceed single hex module capacity.
• Memory: Transitioning to standardized, plug-in memory designs to fit the new backpanel architecture.