From decisions to electronic logic
Computers do not think. They follow instructions step by step to change information.
computation = applying rules reliably at scale
Computation means following clear rules step by step. Even AI works this way, because it performs many small calculations one after another.
Simple decisions can be written as yes/no rules.
George Boole (1854) showed decisions could be described using clear rules that machines could later follow.
machines can execute decisions
Logic is describing decisions as yes or no. Machines can follow these decisions.
A machine only needs: a state → rules → a way to change state
Alan Turing (1936) imagined a very simple rule-following machine, showing that any rule-based process could be done mechanically.
A computing machine keeps track of a situation and applies rules to change it step by step.
Switches can represent yes/no decisions.
Claude Shannon (1937) showed that electrical switches could implement logical rules.
many switches → decisions → machines
A switch can represent a choice: on or off. Many switches together can make decisions.
Computers became flexible when instructions were stored inside the machine.
Ada Lovelace (≈1843) imagined that machines could follow instructions to create many kinds of outputs, not just perform calculations. John von Neumann (1945) formalised this idea.
same hardware, different behaviour
A programmable computer changes behaviour by following different instructions.
Early computers used large fragile switches.
The transistor replaced them with tiny reliable ones.
Bell Labs (1947) invented the transistor.
tiny switches enable scaling
A transistor is a tiny switch made from silicon, a material found in sand.
When billions of switches exist, physics matters: density → power → heat
Brains show another strategy: very low energy per decision.
computing is limited by energy
Every switch uses energy and produces heat. Engineers design computers to stay efficient.
Putting many switches on one chip changed everything.
The Apollo (≈1958) programme bought large quantities, accelerating the industry.
reusable building blocks
Putting many components on one chip made electronics cheaper and easier to build.
Different devices need different trade-offs CPU, MCU, GPU, DSP, FPGA, SOC, ASICs, MEMORY, etc
modern industry is often fabless
ARM fabless approach (1985), enabling companies like Apple Inc. to design chips such as the Apple M series without owning factories.
Chips are designed for different jobs depending on speed, energy and flexibility.
Hardware executes decisions. Software describes them. Layers hide complexity across scales.
Linus Torvalds (1991) created the Linux kernel, which runs from phones to data centres, showing how the same logic operates everywhere.
no magic — only layers of abstraction
Programming means writing instructions that are translated into simple operations. The operating system coordinates everything.
Computers are not thinking machines. They are systems that organise simple decisions at massive scale.