Computer hardware
French mathematician Blaise Pascal designed a gear-based device that could add and subtract, selling around 50 models.
[3] In the 19th century, Englishman Charles Babbage invented the difference engine, a mechanical device to calculate polynomials for astronomical purposes.
[7] Even prior to this, in the mid-19th century mathematician George Boole invented Boolean algebra—a system of logic where each proposition is either true or false.
[10] Building on Babbage's design, relay computers were built by George Stibitz at Bell Laboratories and Harvard University's Howard Aiken, who engineered the MARK I.
[12] Computer architecture requires prioritizing between different goals, such as cost, speed, availability, and energy efficiency.
[14] Cost has also become a significant constraint for manufacturers seeking to sell their products for less money than competitors offering a very similar hardware component.
[16] The most common instruction set architecture (ISA)—the interface between a computer's hardware and software—is based on the one devised by von Neumann in 1945.
From 1986 to 2003, the annual rate of improvement in hardware performance exceeded 50 percent, enabling the development of new computing devices such as tablets and mobiles.
[22] Alongside the density of transistors, DRAM memory as well as flash and magnetic disk storage also became exponentially more compact and cheaper.
Computers also typically have mechanisms for dissipating excessive heat, such as air or liquid coolers for the CPU and GPU and heatsinks for other components, such as the RAM.
[34] Power delivery as well as heat dissipation are the most challenging aspects of hardware design,[35] and have been the limiting factor to the development of smaller and faster chips since the early twenty-first century.
The integrated circuit (IC) chips in a computer typically contain billions of tiny metal–oxide–semiconductor field-effect transistors (MOSFETs).
[citation needed] Using expansion cards for a video processor used to be common, but modern computers are more likely to instead have a GPU integrated into the motherboard.
Reuse of tin, silicon, iron, aluminum, and a variety of plastics that are present in bulk in computers or other electronics can reduce the costs of constructing new systems.
Components frequently contain copper, gold, tantalum,[68][69] silver, platinum, palladium, and lead as well as other valuable materials suitable for reclamation.
Health problems associated with such toxins include impaired mental development, cancer, and damage to the lungs, liver, and kidneys.
[73] Computer components contain many toxic substances, like dioxins, polychlorinated biphenyls (PCBs), cadmium, chromium, radioactive isotopes and mercury.
Circuit boards contain considerable quantities of lead-tin solders that are more likely to leach into groundwater or create air pollution due to incineration.
[74] Recycling of computer hardware is considered environmentally friendly because it prevents hazardous waste, including heavy metals and carcinogens, from entering the atmosphere, landfill or waterways.
There is stringent legislation designed to enforce and encourage the sustainable disposal of appliances, the most notable being the Waste Electrical and Electronic Equipment Directive of the European Union and the United States National Computer Recycling Act.
[75] E-cycling, the recycling of computer hardware, refers to the donation, reuse, shredding and general collection of used electronics.
E-cyclable items include, but are not limited to: televisions, computers, microwave ovens, vacuum cleaners, telephones and cellular phones, stereos, and VCRs and DVDs just about anything that has a cord, light or takes some kind of battery.
