== Analog Computers

Today I want to speak about analog computers. In todays times analog computers are leading a shadowy existence, compared to their digital counterparts. But they are wonderous little machines. And that machines I mean wordly because there exists analog mechanical computers that are models from the world and used to compute and predict tides in certain areas of the world . Also the brain is an enourmous analog computer with a comparatively very small enery budget. It only takes 12 Watt. 12 Watt; that is not even a quarter of the power supply budget of a laptop, which uses 65 Watt. And you can do very heavy lifting with the brain, but back to topic. I want to talk mainly about analog electronic computers, during the world war two those were used to compute ballistic curves. So analog computers can sum up, multiply, divide, integrate and differentiate like their digital counterparts.

When you fire up your browser to visit a website, you most probably did not noticed a very important mechanism underlying the browser and working in the background. Caching. Caches are used everywhere to optimize and improve access times and such in consequence the overall performance (of a site). Caching in the browser for example means, that ideally only the portions of the website that changed are loaded from the www. All else was already loaded before and did not change, thus needs no reload. Portions that are no longer up-to-date become invalidated (also known as cache-invalidation) and are loaded anew from the source. There are two types of very different caches in the computer

USB, SPI, I²C, Sata - all these interfaces is common that they are serial interfaces. Serial interfaces are todays common. But why is that the case, especially for high-speed communication? it sounds simply counterintuitive: Parallel wires can theoretically send more bits per time than on singular wire can. The answer to that question is complex and multilayered. There are multiple different reasons why serial interfaces are preferred over parallel interfaces. Lets start with the obvious ones: The PCB routing of busses of 8, 16, 32 or even 64 bit width gets increasingly complex to route on printed circuits boards (PCBs).The second problem, related to this, is that signal slope need to get transmitted at the same time for all parallel lines (wires), which results in a more complex routing since edges in the strip conductor needs to be compensated. Simply put the additional logic implemented in chips to convert the serial signal to parallel ones again (deserializer) and vice versa (serializer) is much cheaper than the costs of complex routings.