100

It's often said that 0's and 1's are represented by voltage, if the voltage is in the interval [0, 0.9), then it is a 0. If the voltage is in the interval [0.9, 1.5), then it is a 1 (voltages may vary, I'm only giving an example). To some degree, you've mostly created this problem by using an unrealistic example. There is a much larger gap between logical ...


65

We can't. We are just decreasing the probability of errors by adding checks to the data. Depending on what type of data is to be checked, it can either be done via hardware or software, and can take any form from simple checksum bits in serial streams to cyclic state machines allowing only specific transitions to be made at any given time. But it's a ...


49

To keep it simple for now (once you get to college physics this will be expanded), charge is electrons piled up, or lack of electrons where you'd expect there to be some. Electrons have negative charge and protons positive charge. A normal atom has the same number of electrons as protons, so no net charge. On some atoms, the outer few electrons are ...


44

Short answer: You might be able to "connect a battery to a RAM to prevent data loss during power outage", but this depends on the type of RAM. SRAM (Static Random Access Memory) is not DRAM, explained below. SRAMs are found in many electronic devices such as a modern (home) thermostat (uses a battery to retain the settings if the power goes out) and in an ...


43

The approach which you show is quite an old topology for motherboards - it predates PCIe which really puts it back somewhere in the '00s. The reason is primarily due to difficulties of integration. Basically 15 years ago the technology to integrate everything onto a single die was virtually non-existent from a commercial standpoint, and doing so was ...


33

I'm going to disagree that placing a microcontroller on a breadboard qualifies as building a computer on a breadboard. Except for I/O (such as a keyboard and display), a microcontroller by itself is pretty much a complete computer. Just placing it on a breadboard and connecting up a few wires is trivial and can be done in ten minutes. When the OP asked, "...


33

Single event upsets are no longer a thing of space nor aircraft; we have been seeing them happen on the surface for over a decade, maybe two by now. As mentioned though, at least in space applications we deal with upsets using triple voting (each bit is really three, and a two thirds vote wins, so if there is one that changes the other two will cover it.). ...


30

Typically high resolution sin(x) functions would be implemented with a CORDIC (COrdiate Rotation DIgital Computer) algorithm, which can be accomplished with a small number of iterations using only shifts and add/subtract and a small lookup table. The original paper The CORDIC Computing Technique by Jack Volder is from 1959. It also works nicely when ...


28

It wouldn't speed them up. Now it's easy: to make a basic logic gate like a NAND the logic inputs either pull the output to Vdd or to ground. If you would use intermediate levels you would need FETs to go to levels like Vdd/2 or Vdd/4. This would consume more power, and would require more accurately working components, which would need more time to settle to ...


28

It's supposed to look like a passive PFC choke. Real PFC chokes were common in the early-mid 2000s. Those were replaced by active and lighter counterparts on more recent power supplies. Worst passive PFC knock-off I heard about from my friends in China was that the customers associated heavy weight with PFC chokes, so the manufacturers put a large stone in ...


25

Memory addresses are binary numbers. The range of an N-bit (unsigned) binary number is 0 to 2N-1, a total of 2N different values. Since addresses are passed to memory chips as binary numbers, it makes sense to build them in capacities of powers of 2. That way, none of the address space is wasted, and it's easy to combine multiple chips/modules to build ...


24

Like Ali said, charge is a property (or characteristic or feature) of a particle. The particle could be an atom, or it could just be a part of an atom like an electron or a proton. Unfortunately, we can't really say much about why particles have this property, or what causes this property to exist. We can only describe some things we observe about this ...


23

It is not only possible, I have actually done it: see https://www.vttoth.com/CMS/projects/47 Here is what the wiring on the backside of one of the breadboards looked like: Of course it all depends on what components qualify as "basic". In my case, the basic components were 74... series TTL chips, roughly a hundred of them. To build a computer entirely from,...


23

Can we not simply connect a battery to a RAM to prevent data loss during power cuts? So can you tell me why is this not done? Of course we do! It's called battery-backed SRAM, and it's widely used in embedded systems. These days, the cost of NVRAM technology (such as conventional EEPROM, or new FRAM) is low, they can do the same thing without power, so it's ...


22

It requires several features, some of which put the cost up. These include additional transient suppression on signals, which may put additional capacitance on bus signals thus requiring additional engineering/testing and may reduce performance below what's otherwise possible. Also, connectors which longer and shorter pins that ensure that some pins mate ...


22

Water can damage electronics in a few ways. Most people only think of damage due to the conductivity of water. This means that the water will short out the electronics (and this is why water and mains voltages are dangerous. However, with most lower-voltage electronics, the currents that flow through the water are not that substantial and doesn't do a lot ...


21

Let us study the failure mechanisms, and see how they are affected by heat. It is very important to remember that just because a failure mechanism happens faster with temperature, the GPU will not necessarily fail faster! If a sub-component that lasts 100 years at room temperature only lasts 20 years if it is hot, but another sub-component only lasts 1 year ...


19

There are three ways water can damage components: Damage inside IC packages Corrosion Shorting or changing impedance. IC packages There are a lot of ICs that have a specified humidity tolerance, partially because if they do get water in them they will cease to function. Devices that are more affected by this are accelerometers and other MEMS ...


18

You're assuming that the power dissipation is directly related to the clock rate. That's true but there's more. Suppose I have this chip A where only 10% of the chip area (die size) runs at the highest clock rate. Compared to a chip B of equal size where 100% of the circuits are running at the high clock rate, chip A would dissipate only about 1/10th of the ...


17

Resistors and caps have thousands of uses. A couple primary uses for resistors you might see connected directly to the IC pins Pull up/Pull down (100% a logic function ;) Termination to prevent ringing or signal reflections on high-speed digital signals. (Computers would not work if this were not done) Capacitors are used by the bucketload to 'bypass' ...


14

Most computer trig libraries are based on polynomial approximations, which gives the best balance between speed an accuracy. For example, a dozen or so multiplication and add/subtract operations is enough to give full single-precision accuracy for sine and cosine.


14

Reliable production level hot swap typically requires both software and hardware support. You may need software to ensure the device is free'd so that hotswap can occur. The software needs to be able to integrate (size, format, initialize, rebuild) the new device back into the environment. For example if you lose a drive in a redundant array, you need to be ...


13

DIMMs don't dissipate the same power a CPU does, so they don't need the same cooling. In addition, the power the memory and control chips do dissipate is much more spread out physically. Power dissipation may be roughly proportional to clock rate, but that proportionality constant is quite different between a CPU and a memory. The CPU has many more ...


13

Some of the biggest drawbacks of RTL were: much lower noise immunity ( 1x Vbe bias vs 2x) excessive static power dissipation for "0" output state due to low pull-up R for low impedance needed to reduce rise time for "0 to 1" output state to drive pF loads. Such as R2= 50 Ohms. Noise immunity and slew rates were very asymmetric if R2 was high ( e.g. 1k) ...


13

A 1024 x 1 memory chip requires 10 address lines and you get full utilisation of all addresses. Now, if someone brought out a 600 x 1 memory chip, it would still need 10 address lines. It can’t use 9 because that could only uniquely define 512 memory positions. Then think of what would happen if someone wanted to use two of the 600 x 1 memory chips to give ...


12

Microchips are made using a very wide variety of process steps. There are basically two main components to each step - masking off areas to operate on, and then performing some operation on those areas. The masking step can be done with several different techniques. The most common is called photolithography. In this process, the wafer is coated with a ...


12

If you are after a simple answer: Each digital component in a computer is more restricted in the outputs it produces, than in the inputs it accepts. For example, any "input" value from 0V to 2V will be accepted as a 0, but an "output" of 0 will always be in the range 0 to 0.5V. (See duskwuff's answer for some actual values.) This means that each component ...


11

The main advantage to ARM is the power consumption. ARM is very efficient compared to other architectures. At the most basic level, the lower power consumption comes from the processor's instruction set: ARM devices use a RISC instruction set, which is a small but optimized set of instructions. This allows for fewer transistors and instructions, thus saving ...


11

The main reason is that it's simply a lot easier to make circuitry that is always in one of two states than to have it support in-between states. The extra complexity, cost, and speed penalty for compressing more states into a single signal outweigh any advantage gained by the compression. One important convenience of using only two states is that any ...


11

This should not work because it's not a hub. The reason why it works if you have only two devices plugged in is that they can auto-negotiate which pair to use in each direction. When you have three devices plugged in "direction" is no longer well-defined. Back in the day you could just wire devices together in a line without hubs using 10BASE2 cable, ...


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