You can freely build on How the ENIAC Computer Processes Data Using Electronic Pulses
This patent expired in 1981. Every claim — 1 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Sperry Rand Corp
Patent granted
1964
Expired
1981
Forward citations
16
What this patent covers
The patent describes a system that uses electronic pulses to represent information. It generates sequences of pulses and divides them into groups. Some pulses are selected to represent quantitative values (the numbers being calculated), while others represent qualitative values (the instructions or commands for what to do with those numbers). The system reads this data, stores it, and then uses the qualitative pulses to trigger specific switching operations that act upon the quantitative values.
What is now free to use
All 1 claims of US 3120606 are in the public domain. Specifically:
Claim 1: MEANS FOR PRODUCING ELECTRIC PULSES IN SEQUENCE, ELECTRONIC MEANS FOR ALTERNATELY TRANSMITTING CERTAIN ONES OF SAID PULS
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
Does not cover modern binary computing architectures using transistors or silicon chips.
Does not cover software-based programming methods stored on magnetic or solid-state memory.
Does not cover general-purpose computers that do not rely on this specific pulse-sequencing hardware architecture.
Who is building on this today
The technology described here is largely historical, but it laid the groundwork for all modern computer architecture companies like Intel, AMD, and ARM. These companies evolved the concept of electronic switching into the complex logic gates used in modern microprocessors.
Products built on expired version of this technology
ENIAC (Electronic Numerical Integrator and Computer)
How to cite this patent in your documentation
Sperry Rand Corp. US Patent 3120606. Electronic numerical integrator and computer. Granted 1964, expired 1981. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.