Questions tagged [computers]
Questions regarding architectures or design of specific parts, not consumer-related questions.
374
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How can we be sure that computers will never accidentally switch a 0 by a 1?
I've read a bit about the construction of a digital computer in Shocken/Nisan's: The Elements of Computing Systems. But this book says nothing about certain electrical aspects in computers, for ...
41
votes
10
answers
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What is a Charge?
I'm a high school student. I love computers and electronics. Few weeks ago, I thought to build my own electronic gadget but, unfortunately I had not much knowledge in electronics. So, I decided to ...
34
votes
7
answers
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Can we not simply connect a battery to a RAM to prevent data loss during power cuts?
So, I was just wondering about how volatile memory storage loses data when the power to them is cut off. But can we not solve that problem by using a battery in conjunction with a RAM and a ROM and ...
33
votes
2
answers
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How do computers calculate sin values? [closed]
How does a computer calculate a sin value? Logically, when I think about it the only apparent way is to put many sin values into memory, and when a sin value needs to be "calculated" it would just ...
31
votes
5
answers
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How does division occur in our computers?
How does division occur inside digital computers? What is the algorithm for it?
I have searched hard in google but haven't got satisfactory results. Please provide a very clear algorithm/flowchart ...
26
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3
answers
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How do hotswapping computer parts work?
Computers support hotswapping so that a user can replace a harddrive while the system is running. Is that mostly software just powering off the harddrive or is it some special hardware involved? If ...
25
votes
4
answers
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Why do CPU's typically connect to only one bus?
I found a motherboard architecture here:
This looks to be the typical layout of motherboards. EDIT: Well, apparently it's not so typical anymore.
Why does the CPU connect to only 1 bus? That front-...
25
votes
1
answer
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What is this transformer-like component, and why is it not really connected?
Recently, a power surge took out a few components in my PC's ATX power supply. While repairing (I hope), one component in the power drew my attention. I'm an electronics engineer, but I'm confused ...
24
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Explain what is a transistor in plain English!
Can someone care to explain - in plain English - what a transistor is and how it works. I know computers are full of these but don't know much about them.
P.S. I know about this site from another one ...
23
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6
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Does water actually damage or only temporarily disable electronics until drying out?
Does water leave any damage after drying out?
If it does, where and how exactly does it? How can it be repaired?
23
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1
answer
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How does the switch on the back of older computer power supplies work to vary between 110 and 220 volt input?
There is a little switch on the back of older computer power supplies to select between 110 and 220 volt AC input. I imagine this switch enables/disables a 220 to 110 volt transformer. Or perhaps a ...
20
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4
answers
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What are different types of computer architectures?
I am going through the book "Elements of computing systems". This book teaches how to build a whole computer from scratch. While I was just browsing the chapters on computer architecture, I noticed ...
19
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5
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Breadboard computer [closed]
Is it possible to make a simple computer entirely with breadboards and basic electronic components? Is it feasible to, for example construct a scientific calculator in this way?
19
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6
answers
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Reusing laptop monitors
I have a 17" laptop monitor with a 1920x1200 (WUXGA I beleive it's called? or just UXGA?) resolution which I simply love. Now, assuming the laptop dies before the monitor does, would anyone know if it ...
18
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4
answers
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Electrical reason for the minimum altitude (-50 feet) in the computer specs?
Are if there any electrical reasons not to operate or store my Dell OptiPlex computers below the altitude of -50 feet, as written in the specifications?
Screenshot of the original Dell OptiPlex ...
16
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7
answers
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Why do computers only use 0 and 1?
Why do computers only use 0 and 1? Won't the addition of other numbers such as 2 or 3 speed up computers? Also, 2 and 3 can be used to shorten the bit-length of integers (2 and 3 can be used to end an ...
15
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3
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PC ATX12VO (12V only) standard - Why does everybody say it has higher efficiency?
To my understandings, the new 12-volt only standard moves the 5V and 3.3V supplies off from the ATX power supply "box" to the motherboard.
According to PC World (which is cited by Wikipedia),...
15
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5
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How to find socket for ThinkPad keyboard ribbon cable connector?
I am looking for a socket which is able to receive the connector of the ThinkPad X41's keyboard ribbon cable. How do I identify the socket so that I can find it on the (German) market?
Background: I ...
14
votes
2
answers
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3 wires on a (bipolar) DC plug - what are they for?
If got this cable as a power plug for my DELL XPS 15. I want to hook it up to a different power source.
But what are the 3! wires for on a bipolar plug?
13
votes
2
answers
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How are microscopic transistors on microchips made?
How is something like a microchip which is already small as it is able to house even smaller transistors in the millions at such a micro-scale? It seems like such a feat for machine to be able to make ...
12
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8
answers
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How many transistors at minimum do you need to build a general-purpose computer?
I'm wondering what the simplest design for a general-purpose (Turing complete) computer is. To my surprise, I haven't found much on the web. Surely this is a known problem?
12
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My Professor and I are debating about absorption law
So the question is \$(w+y)(wz+wz')wy+y\$ and this is my answer by absorption law where \$A+AB=A\$:
$$
(w+y)(wz+wz!)w y + y\\
B A + A
$$
So the answer is \$A=y\$.
My professor said I ...
11
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3
answers
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Can it be proven that running a GPU at high temps is bad for the card?
If you continuously run your graphics card at between 80°C and 90°C (176°F and 194°F) is it actually bad for the graphics card? I.e. does it reduce the life of the card? Can this be proven? Or is it ...
11
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4
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What exactly gets "worn out" and damaged by heat?
It's quite common knowledge that heat is bad for electronics. That constantly high temperature decreases the expected lifetime of computer parts even if they are not overheating per se.
If, for ...
10
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9
answers
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Was the Intel 186 chip commonly used anywhere? Was it only found in industrial computers? Why not PCs?
I don't think the Intel 186 was in any "home computers" or PCs, but I see other people referencing it as a common chip. Also, I've heard that NEC V20s had the 186 instruction set in addition ...
9
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3
answers
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Why do the large transistors on computer components have their middle pin cut?
I have seen transistors with the middle pin cut used in computer equipment. What do they do?
8
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8
answers
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Can you base a computer around a 32-bit microcontroller?
We all have(mostly) 32-bit machines at our homes. But the 32-bit machines have a microprocessor in them. I was reading an article about the ARM Cortex. Its a 32-bit microcontroller. Now that intrigued ...
8
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3
answers
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Why do TTL integrated circuits have such complicated schematics for logic gates with so many transistors as opposed to RTL?
I'm in the process of building a 4 bit computer out of discrete NPN BJTs and resistors. I'm using RTL, and I've made flip flops, full adders, and demultiplexers, and everything is working fine so far. ...
8
votes
4
answers
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Why does a speed-controlled computer fan require 4 pins?
A "standard" computer fan has two pins; one for power, one for ground. A three-pin fan adds an additional pin used for the signal from the hall-effect sensor. A speed-controlled fan generally uses a ...
8
votes
3
answers
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What is the purpose of an IO shield on a computer case?
What purpose does the IO shield on computers serve? I have been reading a lot of articles (mostly forums) on the internet and can't seem to find a definitive answer.
8
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5
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What are some of the more compelling use cases for plug computers? [closed]
Are plug computers useful for anything besides network-attached storage?
I know that you can hang a bunch of drives off them, maybe set up your own web server. But those uses have limited ...
8
votes
2
answers
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Are 32-bit ALUs really just 32 1-bit ALUs in parallell?
I'm reading the high esteemed text Computer Organization where this picture is found that is supposed to represent a 32-bit ALU:
Is this technology really how it's done, just a lot of 1-bit ALUs, so ...
8
votes
5
answers
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Computer controlled water valve
I'm working on a computer-controlled indoor waterfall. One of the requirements is to be able to change the water pressure via computer interface. I've googled all day long and can't seem to find a ...
8
votes
1
answer
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Backwards compatibility of PCIe AC coupling capacitors
The PCIe base spec mentions that platforms operating only at 2.5GT/s or 5GT/s may use AC coupling capacitors in the 75nF-265nF and that platforms supporting 8GT/s and above must use 176nF-265nF.
...
7
votes
6
answers
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Why are flip-flops criss-crossed?
I want to simulate how a computer works using logic gates. Right now I am trying to build the memory aspect of it.
After looking at various articles and books I see a lot of them using flip-flops/...
7
votes
1
answer
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Enable vendor-disabled hardware on tablet? [closed]
I have a nextbook tablet (one of those cheap things from walmart) that I was looking to try to improve the RAM situation on to breath some new life into it as it apparently only has 1G of it. I ...
7
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3
answers
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How did the vacuum tube computer technicians know when a tube had failed?
I have read that in vacuum tube computers, a tube would fail every couple of days. How did the technicians know that a tube had failed?
Wouldn't a broken tube silently cause the calculations to ...
7
votes
3
answers
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How do sound cards cope with negative voltage?
I feel this is a basic question but I found no answer for it so far.
Let's take a random sound card that lives within a PC. From the connections at the end of the datasheet I assume that it is ...
6
votes
5
answers
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Why are DIMMs not equipped with a heat sink like a CPU?
I know that a DIMM is composed of a set of chips that contain control logic managing the decode and prefetching memory operations. According to a product specification, I found that newer RAM works at ...
6
votes
7
answers
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Why do computer circuits tend to have so many resistors and capacitors? [duplicate]
As someone who has a decent understanding of computer architecture (but not of electrical engineering) I've always wondered why computer circuits tend to have so many resistors, capacitors, and other ...
6
votes
8
answers
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Why can computer circuits recognise only two states?
Computers can only understand binary (that is 0s or 1s). I want to know Is there any way that computers can understand more than 2 states. I know that It is much harder to build components that use ...
6
votes
5
answers
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Why are smartphones and tablets ARM based?
Why don't these devices use Intel processors like laptops do? Why are they restricted to ARM?
Also for Windows 8, do they want ARM just for tablets and smartphones or is it also for laptops/desktops ...
6
votes
5
answers
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trigger alarm with relay from PC sound output
As a total beginner, I have a project of creating an alarm device for a sailing boat. The background is the following:
a Mac-mini collects, by means of different computer programs, alarms from ...
6
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4
answers
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Recommendation of a USB-to-RS-232 chip for an industrial environment
I have bought a device which has an ATmega microcontroller and an FTDI chip which connects to a computer through USB. The FTDI is used only as an RS-232-to-USB adapter.
My problem is that this device ...
6
votes
1
answer
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What is Front Porch and Back Porch of a video signal in CRT display? [duplicate]
What is a Front Porch used for?
What is a Back Porch used for?
What does it mean by active video?
6
votes
3
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Can I "trick" a PC Powersupply to power something other than a Motherboard?
I have a generic PC powersupply I'm using to power a BFL ASIC Bitcoin Miner. It takes an input similar to a PC Video card with two connectors that look like this
...
6
votes
6
answers
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How can I send data to the arduino from the computer?
How can I send data to the arduino from the computer? I'm thinking sort of a prompt on the command line and some commands like "led1 on". Then, the arduino would process that and light up a certain ...
6
votes
3
answers
12k
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Switch on computer with microcontroller
I'm making a simple microcontroller based circuit to turn on a computer when certain events are triggered. I am interfacing it using the PCs soft power switch pins on the front panel header:
There ...
6
votes
4
answers
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How do laptops seamlessly switch from AC wall power to battery
So this is probably a rather simple question but electrical circuits are not my forte. I have been curious about how devices, specifically a laptop, can seamlessly switch between AC wall power (...
6
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3
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Emulate USB device with USB host
Is it in principle possible to connect two computers with a USB A to USB A cable, and have one pretend to be a USB device, and the other act as host?
Assume I have complete control on the software ...