From Calculations to Computation

From ingenious mechanical devices like slide rules and cash registers to the colossal ENIAC that filled entire rooms, and onward to sleek laptops and invisible cloud networks.

Calculators and analog computers

Calculation aids were originally entirely mechanical, including devices such as cash registers, counting wheels, and slide rules. The slide rule, believed to have been introduced by William Oughtred in 1622, became an indispensable tool for technicians and engineers and remained so until the 1970s. Simple electronic calculators began to appear in the late 1940s.

Analog computers (as opposed to digital ones) were used in the 1930s, employing mechanical or electronic components to simulate physical systems. By representing a system’s differential equations, engineers could use electronic adders and integrators (op-amps) to quickly obtain solutions under varying parameters.

ENIAC (Electronic Numerical Integrator and Computer), completed in 1945, was the first programmable, electronic, general-purpose digital computer. While earlier machines had some of these capabilities, ENIAC was the first to combine them all. It contained 17,000 vacuum tubes, stretched 30 meters in length, and consumed 150 kW of electricity.

The modern computers

The 1960s saw the rise of mainframe computers, followed by minicomputers, and eventually the personal computer (PC) around 1980. Digital computers existed in the 1970s, but in 1981 IBM launched the IBM Personal Computer (Model 5150), setting the standard for PCs and bringing personal computing into the mainstream with Microsoft’s MS-DOS. This machine featured an Intel 8088 CPU running at 4.77 MHz, 640 KB of memory, a floppy disk drive, a monochrome display, and could be programmed in BASIC. It had no mouse—everything was controlled via the keyboard.

Modern computers are roughly one million times faster and can process ten billion times more data than early PCs, making them capable of simulating thousands of IBM 5150 systems in real time—simultaneously.

Data storage has evolved from punched cards, punched tape, magnetic tape, floppy disks, hard drives, and CDs to today’s SSDs and cloud storage solutions.