How Alan Turing Designed Early Computer Memory Systems

A 1951 patent by Alan Turing and colleagues describing methods for moving data between different storage types in early digital computers.

What it covers

This patent describes a system for managing data movement between a high-speed, limited-capacity memory (like a delay line or register) and a larger, slower secondary storage medium. It focuses on the timing and synchronization required to transfer information chunks between these two tiers. By using specific control signals, the system ensures that data is correctly addressed and read or written without losing the sequence of bits. This was essential for computers that used acoustic delay lines, where data had to be constantly refreshed.

What it doesn't cover

• —Does not cover modern solid-state drive (SSD) flash memory architectures.
• —Does not cover graphical user interface (GUI) data management.
• —Does not cover cloud-based distributed storage systems.
• —Does not cover non-digital or purely mechanical calculating machines.

The clever bit

The invention cleverly uses the physical timing of the hardware itself to dictate the flow of data, rather than relying on complex software-based interrupt systems that didn't exist yet.

Why it matters

This patent represents one of the earliest attempts to solve the 'memory wall' problem—the speed gap between fast processors and slow storage. It reflects the foundational work done at the National Physical Laboratory in the UK, which helped define the architecture of the ACE (Automatic Computing Engine) computer.

Real-world examples

• 1.The Pilot ACE computer
• 2.Early mercury delay line memory systems