# How Wang An Invented the Magnetic Pulse Memory Core

> A 1949 invention by An Wang that used magnetic cores to store and transfer binary data, forming the backbone of early computer memory.

- **Patent:** US 2708722
- **Original title:** Pulse transfer controlling device
- **Owner:** Individual
- **Granted:** 1955
- **Status:** Public domain (expired)
- **Times cited:** 74
- **Field:** semiconductors, mechanical, telecommunications

## What it does

This device uses magnetic cores to control the transfer of electrical pulses. It functions as a memory element by shifting information from one magnetic state to another. By applying specific current pulses, the device can store a bit of data as a magnetic orientation and then transfer that state to the next element in a sequence. This mechanism allowed early computers to store and move data without relying on fragile vacuum tubes.

## What it does NOT cover

- Does not cover semiconductor-based RAM or flash memory storage.
- Does not cover optical data storage or laser-based reading methods.
- Does not cover software-based data processing algorithms.

## The clever bit

It solved the problem of how to move data bits through a system without them getting lost or corrupted, using the physical property of magnetic hysteresis to hold a state indefinitely.

## Real-world examples

1. Magnetic core memory modules in 1960s mainframe computers
2. Early digital calculators
3. Control systems for the Apollo Guidance Computer

## Why it matters

This invention was fundamental to the development of reliable digital computers. Before this, memory was bulky and prone to failure. An Wang's work enabled the creation of magnetic core memory, which was the standard for high-speed computer storage from the 1950s through the 1970s.

## Frequently asked questions

### What does How Wang An Invented the Magnetic Pulse Memory Core cover?

A 1949 invention by An Wang that used magnetic cores to store and transfer binary data, forming the backbone of early computer memory.

### Who owns patent US 2708722?

Individual owns this patent, granted in 1955.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 2708722 cited by?

This patent has been cited by 74 later patents that build on its ideas.

### What problem does this patent solve?

This invention was fundamental to the development of reliable digital computers. Before this, memory was bulky and prone to failure. An Wang's work enabled the creation of magnetic core memory, which was the standard for high-speed computer storage from the 1950s through the 1970s.

### What does this patent NOT cover?

Does not cover semiconductor-based RAM or flash memory storage.

**Full plain-English explainer:** https://patentbrief.org/patent/us/2708722/magnetic-core-memory-wang

**Original patent:** https://patents.google.com/patent/US2708722

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [How Alan Turing Designed Early Computer Memory Systems](https://patentbrief.org/patent/us/2799449/turing-computer-data-storage) — A 1951 patent by Alan Turing and colleagues describing methods for moving data between different storage types in early digital computers.
- [How Early Hard Disk Drives Accessed Data Quickly](https://patentbrief.org/patent/us/3503060/hard-disk-drive) — A 1970 patent detailing a mechanical system for moving read-write heads across magnetic disks to retrieve stored information rapidly.
- [How the ENIAC Computer Processes Data Using Electronic Pulses](https://patentbrief.org/patent/us/3120606/eniac-electronic-computer) — A foundational 1964 patent describing how the ENIAC computer used sequences of electronic pulses to store, read, and process numerical and qualitative data.
- [The Invention of the Transistor](https://patentbrief.org/patent/us/2524035/point-contact-transistor) — Bell Labs' 1950 patent for the point-contact transistor, the fundamental electronic component that makes all modern computing possible.
- [The Invention of the Junction Transistor](https://patentbrief.org/patent/us/2569347/junction-transistor) — William Shockley's 1951 patent for the junction transistor, the fundamental building block of all modern digital electronics.