less_retarded_wiki/computer.md
2024-03-10 17:17:47 +01:00

16 KiB

Computer

The word computer can be defined in many ways and can also take many different meanings; a somewhat common definition may be this: computer is a machine that automatically performs mathematical computations. We can also see it as a machine for processing information, manipulating symbols or, very generally, as any tool that helps computation, in which case one's fingers or even a mathematical formula itself can be considered a computer. Here we are of course mostly concerned with electronic digital computers.

Electronic digital computer turned out to be one of the greatest technological inventions in history for many reasons -- firstly computers allowed creation of many other things which previously required too complex calculations, such as highly complex planes, space rockets and undreamed of factories (and, of course, yet more powerful computers which is why we've seen the exponential growth in computer power), they also allow us to crunch extreme volumes of data and accelerate science; secondly they offered extremely advanced work tools like robots, virtual 3D visualizations, artificial intelligence and physics simulators, and they also gave us high quality, cheap multimedia and entertainment like games -- with computers anyone can shoot video, record music, carry around hundreds of movies in his pocket or fly a virtual plane. Most important however is probably the fact that computers enabled the Internet -- by this they forever changed the world.

We can divide computers based on many attributes, e.g.:

            ______________
           |  ________  | \_
           | |>..     | | : \                        ||
           | |        | | :  ]                   |:==-'              
           | |________| | :_/                 ___||___
    ___    |____________|_/'.    ___         /########\
   / \ \        \...../      '. / \ \        |""""""""|
  |;:;| |  _____/_____\_____  :|;:;| |       |O O O O |
  |;:;| |:|[o][o],,, === |  |.'|;:;| |       || | | | |
  |___|_| |______________|__|:.|___|_|       || | | | |
                      __...--':              ||,|,|,|,|
                 .-'''    .-''               \########/
     ___________;__     _:_
    /:::::::.::'::/|   /-'-)
   /:::::::'.:.:://   (___/ 
   """""""""""""""   

On the left typical personal computer, with case, monitor, keyboard, mouse and speakers; on the right a pocket mechanical calculator of the Curta type.

Computers are theoretically studied by computer science. The kind of computer we normally talk about consists of two main parts:

The power of computers is mathematically limited, Alan Turing mathematically proved that there exist problems that can never be completely solved by any algorithm, i.e. there are problems a computer (including our brain) will never be able to solve (even if solution exists). This is related to the fact that the power of mathematics itself is limited in a similar way (see Godel's theorems). Turing also invented the theoretical model of a computer called the Turing machine. Besides the mentioned theoretical limitation, many solvable problems may take too long to compute, at least with computers we currently know (see computational complexity and P vs NP).

And let's also mention some interesting statistics and facts about computers as of 2024. The fist computer in modern sense of the word is frequently considered to have been the Analytical Engine designed in 1837 by an Englishman Charles Babbage, a general purpose mechanical computer which he however never constructed. After this the computers such as the Z1 (1938) and Z3 (1941) of a German inventor Konrad Zuse are considered to be the truly first "modern" computers. Shortly after the year 2000 the number of US households that had a computer surpassed 50%. The fastest supercomputer of today is Frontier (Tennessee, USA) which achieved computation speed of 1.102 exaFLOPS (that is over 10^18 floating point operations per second) with power 22.7 MW, using the Linux kernel (like all top 500 supercomputers). Over time transistors have been getting much smaller -- there is the famous Moore's law which states that number of transistors in a chip doubles about every two years. Currently we are able to manufacture transistors as small as a few nanometers and chips have billions of them. { There's some blurriness about exact size, apparently the new "X nanometers" labels are just marketing lies. ~drummyfish }

Typical Computer

Computers we normally talk about in daily conversations are electronic digital mostly personal computers such as desktops and laptops, possibly also cell phones, tablets etc.

Such a computer consists of some kind of case (chassis), internal hardware plus peripheral devices that serve for input and output -- these are for example a keyboard and mouse (input devices), a monitor (output device) or harddisk (input/output device). The internals of the computer normally include:

  • motherboard: The main electronic circuit of the computer into which other components are plugged and which creates the network and interfaces that interconnect them (a chipset). It contains slots for expansion cards as well as connectors for external devices, e.g. USB. In a small memory on the board there is the most basic software (firmware), such as BIOS, to e.g. enable installation of other software. The board also carries the clock generator for synchronization of all hardware, heat sensors etc.
  • CPU (central processing unit): Core of the computer, the chip plugged into motherboard that performs general calculations and which runs programs, i.e. software.
  • RAM/working memory/main memory: Lower capacity volatile (temporary, erased when powered off) working memory of the computer, plugged into motherboard. It is used as a "pen and paper" by the CPU when performing calculations.
  • disk: Non-volatile (persisting when powered off) large capacity memory for storing files and other data, connected to the motherboard via some kind of bus. Different types of disks exist, most commonly hard disks and SSDs.
  • expansion cards (GPU, sound card, network card, ...): Additional hardware cards plugged into motherboard for either enabling or accelerating specific functionality (e.g. GPU for graphics etc.).
  • PSU (power supply unit): Converts the input electrical power from the plug to the electrical power needed by the computer.
  • other things like fans for cooling, batteries in laptops etc.

Notable Computers

Here is a list of notable computers.

{ Some nice list of ancient computers is here: https://xnumber.com/xnumber/frame_malbum.htm. ~drummyfish }

name year specs (max, approx) comment
brain -500M 86+ billion neurons biological computer, developed by nature
abacus -2500 one of the simplest digital counting tools
Antikythera mechanism -125 ~30 gears, largest with 223 teeth 1st known analog comp., by Greeks (mechanical)
slide rule 1620 simple tool for multiplication and division
Shickard's calculating clock 1623 17 wheels 1st known calculator, could multiply, add and sub.
Arithmometer 1820 6 digit numbers 1st commercial calculator (add, sub., mult.)
Difference Engine 1822 8 digit numbers, 24 axles, 96 wheels mech. digital comp. of polynomials, by Babbage
Analytical Engine design 1837 ~16K RAM, 40 digit numbers 1st general purpose comp, not realized, by Babbage
nomogram 1884 graphical/geometrical tools aiding computation
Z3 1941 176B RAM, CPU 10Hz 22bit 2600 relays 1st fully programmable electronic digital computer
ENIAC 1945 ~85B RAM, ~5KHz CPU, 18000 vaccum tubes 1st general purpose computer
PDP 11 1970 4M RAM, CPU 1.25Mhz 16bit legendary mini
Apple II 1977 64K RAM, 1MHz CPU 8bit popular TV-attached home computer by Apple
Atari 800 1979 8K RAM, CPU 1.7MHz 8bit popular TV-attached home computer by Atari
VIC 20 1980 32K RAM, 1MHz CPU 8bit, 20K ROM successful TV-connected home computer by Commodore
IBM PC 1981 256K RAM, CPU 4.7MHz 16bit, BASIC, DOS 1st personal computer as we know it now, modular
Commodore 64 1982 64K RAM, 20K ROM, CPU 1MHz 8bit very popular TV-connected home computer
ZX Spectrum 1982 128K RAM, CPU 3.5MHz 8bit, 256x192 screen successful UK TV-connected home comp. by Sinclair
NES/Famicom 1983 2K RAM, 2K VRAM, CPU 1.7MHz 8bit, PPU TV-connected Nintendo game console
Macintosh 1984 128K RAM, CPU 7MHz 32bit, floppy, 512x342 very popular personal computer by Apple
Amiga 1985 256K RAM, 256K ROM, CPU 7MHz 16bit, AmigaOS personal computer by Commodore, ahead of its time
NeXT 1988 8M RAM, 256M drive, CPU 25MHz 32bit, NeXTSTEP OS famous workstation, used e.g. for Doom dev.
SNES 1990 128K RAM, 64K VRAM, CPU 21MHz 16bit game console, NES successor
PlayStation 1994 2M RAM, 1M VRAM, CPU 33MHz 32bit, CD-ROM popular TV-connected game console by Sony
TI-80 1995 7K RAM, CPU 980KHz, 48x64 1bit screen famous programmable graphing calculator
Deep Blue 1995 30 128MHz CPUs, ~11 GFLOPS 1st computer to defeat world chess champion
Nintendo 64 1996 8M RAM, CPU 93MHz 64bit, 64M ROM cartr. famous TV-connected game console
GameBoy Color 1998 32K RAM, 16K VRAM, CPU 2MHz 8bit, 160x144 handheld gaming console by Ninetendo
GameBoy Advance 2001 ~256K RAM, 96K VRAM, CPU 16MHz 32bit ARM, 240x160 successor to GBC
Xbox 2001 64M RAM, CPU 733MHz Pentium III TV-connected game console by Micro$oft
Nintendo DS 2004 4M RAM, 256K ROM, CPU ARM 67MHz, touchscreen famous handheld game console by Nintendo
Nintendo Wii 2006 24M RAM, 512M ROM, SD, CPU PPC 729M famous family TV console with "stick" controllers
iPhone (aka spyphone) 2007 128M RAM, CPU ARM 620MHz, GPU, cam., Wifi, 480x320 1st of the harmful Apple "smartphones"
ThinkPad X200 2008 8G RAM, CPU 2.6GHz, Wifi legendary laptop, great constr., freedom friendly
ThinkPad T400 2008 8G RAM, CPU 2.8GHz, Wifi legendary laptop, great constr., freedom friendly
Raspberry Pi 3 2016 1G RAM, CPU 1.4GHz ARM, Wifi very popular tiny inexpensive SBC
Arduboy 2016 2.5K RAM, CPU 16MHz AVR 8bit, 1b display tiny Arduino open console
Pokitto 2017 36K RAM, 256K ROM, CPU 72MHz ARM indie educational open console
Raspberry Pi 4 2019 8G RAM, CPU 1.5GHz ARM, Wifi tiny inexpensive SBC, usable as desktop
Frontier 2021 9000+ 64 2GHz CPUs, 37000+ GPUs fastest supercomputer to date, 1st with 1+ exaFLOPS
Deep Thought fictional computer from Hitchhiker's Guide ...
HAL 9000 fictional AI computer (2001: A Space Oddysey)
PD computer planned LRS computer
Turing machine important theoretical computer by Alan Turing

TODO: mnt reform 2, pinephone, 3DO, ti-89, quantum?