Turing’s abstract ‘universal computing machine’ of 1936, soon known simply as the universal Turing machine, consists of a limitless memory, in which both data and instructions are stored, and a scanner that moves back and forth through the memory, symbol by symbol, reading what it finds and writing further symbols. By inserting different programs into the memory, the machine is made to carry out different computations. It was a fabulous idea—a single machine of fixed structure which, by making use of coded instructions stored in memory, could change itself, chameleon-like, from a machine dedicated to one task into a machine dedicated to a quite different one.
Turing showed that his universal machine is able to accomplish anytask that can be carried out by means of a rote method (hence the characterization ‘universal’). Nowadays, when so many people possess a physical realization of the universal Turing machine, Turing’s idea of a one-stop-shop computing machine might seem as obvious as the wheel. But in 1936, when engineers thought in terms of building different machines for different purposes, Turing’s concept was revolutionary.
Here is a list of handy shortcut keys for Ubuntu:
General keyboard shortcuts
Ctrl + A = Select all
Ctrl + C = Copy the highlighted content to clipboard
Ctrl + V = Paste the clipboard content
Ctrl + N = New (Create a new document, not in terminal)
Ctrl + O = Open a document
Ctrl + S = Save the current document
Ctrl + P = Print the current document
Ctrl + W = Close the close document
Ctrl + Q = Quit the current application
Keyboard shortcuts for Terminal
Ctrl + A = Move cursor to beginning of line
Ctrl + E = Move cursor to end of line
Ctrl + C = kills the current process.
Ctrl + Z = sends the current process to the background.
Ctrl + D = logs you out.
Ctrl + R = finds the last command matching the entered letters.
Enter a letter, followed by Tab + Tab = lists the available commands beginning with those letters.
Ctrl + U = deletes the current line.
Ctrl + K = deletes the command from the cursor right.
Ctrl + W = deletes the word before the cursor.
Ctrl + L = clears the terminal output
Shift + Ctrl + C = copy the highlighted command to the clipboard.
Shift + Ctrl + V (or Shift + Insert) = pastes the contents of the clipboard.
Alt + F = moves forward one word.
Alt + B = moves backward one word.
Arrow Up/Down = browse command history
Shift + PageUp / PageDown = Scroll terminal output
Keyboard shortcut for Nautilus
Shift + Ctrl + N = Create New Folder
Ctrl + T = Delete selected file(s) to trash
Alt + ENTER = Show File/Folder Properties
Ctrl + 1 = Toggle View As Icons
Ctrl + 2 = Toggle View As List
Shift + Right = Open Directory (Only in List View)
Shift + Left = Close Directory (Only in List View)
Ctrl + S = Select Pattern
F2 = Rename File
Ctrl + A = Select all files and folders
Ctrl + W = Close Window
Ctrl + Shift + W = Close All Nautilus Windows
Ctrl + R = Reload Nautilus Window
Alt + Up = Open parent directory
Alt + Left = Back
Alt + Right = Forward
Alt + Home = go to Home folder
Ctrl + L = go to location bar
F9 = Show sidepane
Ctrl + H = Show Hidden Files
Ctrl + + = Zoom In
Ctrl + - = Zoom Out
Ctrl + 0 = Normal Size
I have a quad-core and oct-core machines and one of the things I generally do is to run my code only on single core. However to do this one needs to boot OS with single core configuration. With windows it is fairly easy to do:
- Go to run (Windows + R button)
- type msconfig
- press enter
- In boot click Advanced options.. button (more…)
Mahdi Yusuf did some interesting analysis of keys frequently used in programming languages, well this may not lead us to any conclusion nonetheless is quite interesting:
You might argue that the variables names being used will alter the results, but as most languages programming have conventions for naming but we can assume a decent spread for variable names. I don’t offer conclusions, just poorly layout the facts. Although the heat map does miss out on things like shift and caps. ex. in perl with the dollar sign. ($)
Whitespace hasn’t been taken into consideration (tabs and spaces) which would have been a cool thing to see.
The data that was used to gather this information was spread amongst various popular Github projects.
Here are some of the keyboard images from his analysis:
C Keyboard Frequency Map
C++ Keyboard Frequency Map
Supercomputers have an energy problem — one that threatens to curb their steady evolution. If we continue to ratchet up the speed of our supercomputers using today’s technologies, by the end of the decade they’ll draw as much power as a sizable town. (more…)