Week 1: Overview of Computers

This is a work in progress.  I already know a lot about computer hardware, due to my long experience with computers (I first used computers before I could read, which is not so unusual these days.  However, the difference was that I was using a Mac Plus and PowerMacs, and later additionally PCs running Windows 95, rather than tablets or smartphones, as they did not really exist yet).  At the most basic, a computer needs a processor (Central Processing Unit, or CPU for short), memory, and some more permanent storage (a calculator may forgo the storage, although graphing calculators normally have at least those three), although most computers also have some kind of means of display, to show the results of work done, whether directly attached or accessed over a network, as well as an input device of some kind, usually a keyboard and a mouse, although it can be something else, like a trackball, joystick, or trackpad.  In the very earliest days computers used punchcards for input, but this is very rare now.  Computers normally support other sorts of peripheral devices, such as printers and scanners, external storage devices such as portable hard or flash drives or CD/DVD/Blu-Ray drives.  Optical drives are less common now, as most software and media is downloaded over the Internet rather than purchased on a disc, but they are still useful for making backups (dual-layer Blu-ray discs can hold up to 50GB of data, single-layer 25GB) and playing media when offline or in a bandwidth constrained environment, such as on a train.  Modern computers frequently have graphics processing capability on the same chip as the Central Processing Unit, although it is still quite common for all but systems requiring very basic graphics capability to have a separate Graphics Processing Unit (GPU), whether it is on a replaceable card or not.   GPUs can be used for compute as well as for graphics, leading to increased demand in server systems.  For example, the MacBook Pro that I am typing this on has onboard Intel HD Graphics on the same chip as the CPU, and an additional onboard Radeon Pro graphics chipset.  I could additionally augment this with another GPU connected over Thunderbolt (an external extension of the internal PCI-express bus) if I chose to do so.  My particular laptop also supports networking via Thunderbolt in addition to wireless, and also has Bluetooth for peripherals such as keyboards and mice (I have an external number pad connected using Bluetooth).



To sum up, computers have a processor, memory, storage (hard drive/SSD), and some type of input (such as a keyboard and mouse) and output (monitors, printers).