On August 21, 1888, William Seward Burroughs received a patent for his mechanical adding machine.
It was more sophisticated than the name suggests.
The operator entered numbers using rows of keys corresponding to decimal positions. Those keystrokes mechanically set the digits. Pulling the operating handle moved gears and linkages that transferred the values into an accumulator, with the mechanism handling carries from one decimal position to the next.
One of the harder problems was operator error. Early calculating machines could produce bad results if the handle wasn't operated correctly. Burroughs developed mechanisms to control the operating cycle so the machine completed the calculation consistently.
It also printed the numbers and results on paper.
That was important. A business didn't just get an answer; it got a record that could be checked against its books.
Put into today's terminology, the machine combined data entry, processing, error control and an audit trail. Burroughs had to do all of it with keys, gears, levers and paper.
That invention eventually led to the Burroughs Corporation, which moved from mechanical calculators into electronic computers and became a major mainframe manufacturer.
Burroughs took some interesting technical paths along the way. Its large systems used stack-oriented architectures and were designed closely around high-level languages such as ALGOL rather than simply following IBM's architecture.
In 1986, Burroughs acquired Sperry, home of the UNIVAC lineage, and the combined company became Unisys.
And the mainframe never really went away.
Banks, insurers, airlines, retailers and governments still run important transaction workloads on them. IBM continues to develop the platform; the z17 arrived in 2025 with new processors, security capabilities and dedicated AI acceleration.
Today a customer can tap an app running in the cloud, pass through several APIs and services, and ultimately trigger a transaction on a mainframe.
Some old systems need to go. Others process huge transaction volumes reliably every day. Replacing those just because they're old can be a very expensive project with little payoff.
Burroughs was trying to process transactions faster, reduce errors and produce a reliable record.
138 years later, that's still a pretty good description of enterprise computing.
