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53 Cards in this Set
- Front
- Back
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Name the 2 core components of an Operating System |
- Kernel - Shell |
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What are the 3 tasks of an operating system? |
- Accept & execute commands & requests from the user and from the software the user is running - load, manage, and execute software - manage the computer's hardware resources. |
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What are the small programs kernels use called? |
Supervisors |
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name 3 things hardware assists in providing |
-memory protection - illegal instruction traps - system call |
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what is Hardware Abstraction |
a task the operating system performs. makes hardware appear generic to software. |
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what is a Process? |
a program that is loaded and being executed, it has data and control flow |
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what is a program? |
a file containing source code, or object code. it Specifies data and control flow. |
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what does a process need? |
allocated resources - access to hardware, memory and processor time. |
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when running multiple programs what two things does the operating system handle? |
allocation and scheduling. |
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what are the 5 steps of the process lifecycle? |
- new - ready - running - blocked - terminated |
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what lead to operating systems emerging? |
protection of comptuers from misbehaving programs helping operators to manage jobs to reduce idle time |
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what does DDR stand for? |
Double Data Rate |
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what is DRAM? how does it operate |
Dynamic Random Access Memory asynchronous RAM which makes it quicker than SDRAM. |
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what is SDRAM? how does it operate? |
Synchronous dynamic random access memory SDRAM waits for the clock signal |
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what is DIMM? |
Dual Inline Memory Module |
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what is SIMM? |
Single Inline Memory Module |
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what is WSI |
Wafer Scale Integration - a whole computer on a silicon wafer. |
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How does bubble memory work? |
Magnetizes points in a crystal. each bubble could be created along one edge of the crystal, when the bubble reaches the other side of the crystal they could be read. |
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what type of memory was Bubble Memory? |
Non-Volatile, mutable memory. |
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what is twistor memory? |
like magnetic core memory, but magnetic tape was wrapped around the wire, rather than the wire being threaded through magnets. |
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what is magnetic core memory? |
donut-shaped magnets that stored clockwise/anti-clockwise charges. by changing direction we changed the store data. each magnet had 3 wires running through it. |
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what was a williams-kilburn Tube |
the first version of digital RAM, displayed with lights in binary format. 1 = on, 0 = off. used CRT screens. |
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what were the 4 main parts of an Acousting Delay Line? |
- Amplifier - Tranducer (Speaker) - Tranducer (microphone) - a Medium for it to transmit through (mercury) |
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what is interleaving? |
division of memory into parts that creates its own MAR and MDR. While one is being written to, another can be read. |
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what is MAR? |
memory address register. holds the address of the memory we want to work with |
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what is MDR? |
memory data register. holds the data |
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how does virtual memory work? |
combines storage and memory simulating memory of larger size than is physically available. |
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what are the 3 forms of Locality of Reference? |
Longest Resident - evict the page in memory the longest. Least Recently Used - evict the least used page. Least Frequently Used - kickout the one used least frequently. if multiple matches, fall back to least recently used. |
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what are the 3 approaches to locality? |
Temporal Locality Spatial Locality Sequential Locality |
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what are two forms of memory partitioning? |
Fixed partitions and variable partitions. fixed = same size memory partitions, variable = different size partitions. |
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name 3 "fits" of putting data into memory |
- first fit (into the first that will take it) - largest fit (largest partition) - best-fit (closest to the size of the data) |
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name 4 kernel structures |
monolithic layered microkernel hybrid |
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what are 4 goals of memory management |
allow as many processes as possible respond to memory requirements prevent unauthorised changes to memory implement these tasks as quickly as possible |
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what are the 5 main parts of a computer? |
- input/output - processor - clock - memory - instruction set |
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what is memory latency? |
the delay between the request of memory being read, and the release of the data corresponding with the request. |
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name 2 negative effects of overclocking |
- increases chances of errors - increases heat output |
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what is the difference between parallel and distributed processing? |
parallel = 1 process split across multiple processors. distributed = processors run individual programs in separate memory and communicate with eachother. |
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what is SIMD? |
single instruction, multiple data |
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what is MIMD? |
multiple instructions, multiple data |
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what are the functions of the ALU? |
arithmetic logic unit, perform arithmetic functions for logical units - whole integer values. |
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what is a fourth generation language? |
a more programmer friendly language that aims to reduce time required for programmer input through efficiency with english-like words and phrases, icons, and graphical interfaces or symbolic representations. |
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what is kernel and user mode? |
Kernel mode = system mode. when in system mode it is assumed to be executing trusted software. user mode is to use all forms of applications which are considered untrusted hardware, and they access the kernel through system calls for input/output. |
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what is static typing? |
programming without declaring variables |
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what is dynamic typing? |
programming where variables must be declared before they are used. |
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what is the von neuman bottleneck? |
processor speeds are increasing significantly, but memory speed is not increasing at such a fast rate, leading to a bottleneck while the processor idles until tasks are loaded. |
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what is the machine cycle? |
fetch, decode, execute |
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3 known ways to reduce heat problems? |
heatsink watercooling liquid nitrogen |
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what is CISC |
complex instruction set computing |
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what is RISC |
reduced instruction set computing. faster than CISC as you can do pipelining during the machine cycle |
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what is pipelining? |
the process of improving performance by running fetch while the previous instruction set is being decoded or executed. |
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what are the 3 minimum registers a computer needs? |
program counter - counts location for next fetch cycle instruction register - holds the instruction set. accumulator - holds the data we're currently working with. |
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what 4 parts make up a turing machine? |
- infinitely long tape - a read/write head - an action table that has instructions - a register that stores the current state |
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what is the turing test? |
given enough time a turing machine can complete anything a computer can do. if it is to be classed as a computer it must be turing-complete. |
