# Tagged Questions

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### Fundamental idea of this memory denial of service simulation using array copy?

I am just watching this lecture Computer Organization - Introduction And Basics where the lecturer mentions about using a simple code to demonstrate how memory denial of service can be simulated in ...
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### Using specified logic gates, how to get an exact output

So, I'm working on the decoding logic of a cpu, and I'd like to know if there is a methodology to know how many logic gates do I need and how to use them... Like for example, I have an architecture ...
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### What are some “easy” unreasonable implications of O(1) time memory access?

If you are given a memory address $n$ bits long, then you need to at least process those bits. Hence, if you have $N$ memory available, addressed by $n$ bits, it would take $O(\mathbf{log}(N)) = O(n)$...
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### What is an addressable cell size?

This question started with a quiz question from my university: Consider a big-endian computer system with an addressable cell size of one byte. The values in memory cells 372 to 375 are shown in the ...
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### How does CPU actually retrieve data from memory when you call a variable in a programming language?

As I have understood from all the internet sources I can get to, when you declare and initialize a variable in java, you are allocating this data, say an 8-byte float, in a particular memory cell in ...
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### Mapping several memories to one address space

I am trying to understand deeply how memories work in computers, and I faced the next difficulty. Let's say we have a device with two memory chips but only one address space (for example, 0x00000000 ...
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According to a textbook assigned for my class, if I have memory that is 4M X 16, to address this memory (assuming word addressing), we need to be able to uniquely identify $2^{12}$ different items, ...
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### Valid-invalid bit in a process page table

Valid-invalid bit is used to indicate whether a page in a process’s page table is valid or not. Why is it needed? Does that mean that each page table has a certain minimum size, i.e. it can ...
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### Valgrind: what is the difference between a store and a modify? [closed]

I am using the Vlagrind lackey tool to examine the full memory reference string of a running computer program and wonder what the difference between a "store" and a "modify" might be - and do these ...
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### Applications affected by memory performance

I'm writing a paper on the topic of applications affected more by memory performance than processor performance. I've got a lot written regarding the gap between the two, however I can't seem to find ...
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### DFA memory bandwidth

When we talk about DFA, we say that each new character from the input requires one memory access. What does that mean? This is what I think about this. Please tell me is this right? For example, I ...
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### static paging vocabulary request

What is the term for an algorithm that always requests the same sequence of pages? I recall seeing this concept before buti haven't been able to find anything on Google without more specific ...
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### How a program is copied to RAM from harddisk

I know that for executing a program, it should be copied to RAM. But the problem is whole of it may not be copied always. Since the size of the RAM is limited, there is mechanism called virtual ...
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What is the difference between dynamic loading and dynamic linking? Both systems seem to allow shared libraries, but I am struggling to differentiate between them.
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### Finding cache block transfer time in a 3 level memory system

Following question was asked in one of entrance exams for a graduation programme. Please help me try to solve it : A computer system has an L1 cache, an L2 cache, and a main memory unity ...
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### Changing from Kernel mode to User mode (and vice versa)

I am reading Operating Systems book by Galvin. Galvin explains, what are kernel & user modes, instruction privileges given for both modes & also about mode-bit. But I am interested to know how ...