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The Mechanical Universe

Draw with your finger


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EMI, RFI, EMC, EMS, What's the Difference?
EMI, RFI, EMC, and EMS all refer to different aspects of radio frequency interference which may cause elecronic devices to malfunction. Correcting these problems can be an art and a science. More ...

Inkscape Preferences
Inkscape is a highly configurable application. Many of these configuration options can be set through the Preferences dialog box. There is probably a hundred things you can configure through the Preferences dialog box. Here I'll describe a couple of the most important ones. More ...

Inkscape Layers and Z-Order
Inkscape's use of the Z axis is represented by layers and is called z-order. When you first draw an object on an empty canvas, it has a z-order of 1. If you draw a second object, it has a z-order of 2. If you draw a third object, it has a z-order of 3 and so on. More ...

Html5 section vs article Element Best Practices
Many new semantic elements where added to HTML5. The purpose of most of these new elements was easily discernible. But a web search reveals that there is much confusion about the relationship between the article and the section element. More ...

PowerShell Script to Show Last 5 Errors in Event Log
The Windows System eventlog is one of the most powerful components of the operating system because it keeps a log of everything that happens. Here I provide a powershell script to display the last 5 error entries in the log. More ...

Introduction to Windows PowerShell
PowerShell is a more powerful replacement for the command shell. this article explains how to run PowerShell and how to create and run PowerShell scripts. More ...

Regular Expression: Alternation
In this article you learn how to create an alternation regular expression that will match alternate patterns in a string. More ...

Regular Expression Basics : How many Matches?
A Regular Expression (regex) is a sequence of characters that define a pattern that allows you to search, match, locate, replace, manipulate, and manage text. In this article you'll learn how to use regular expressions to count the number of matches. More ...

Inkscape Basic Fill
In Inkscape you can fill a shape with just about any color, texture, or pattern that you desire. In this article we discuss how to fill a shape with a basic color. More ...

Inkscpe Snap Controls Bar
some Inkscape users find snap annoying and so they disable it. Other Inkscape user's could not possibly work without snap. You can convert SVG to STL to print 3D models. But to do that you need accuracy that you cannot achieve without snap. More ...

Introduction to Operating Systems
An operating system is software that acts as an intermediary between a computer user and the computer's applications and hardware. An operating system can be viewed as a resource allocator. Resources might be CPU time, memory space, file storage space, and input/output (I/O) devices. More ...

The Difference Between EoP and PoE
Ethernet over Power (EoP) is a technology for sending network data over power lines. Power over Ethernet (PoE) is a technology for sending power over Ethernet network cables. More ...

A JavaScript Function That Returns a Function
Its a fad now in JavaScript to code functions that return functions in order to avoid declaring global variables but the procedure is inefficient and unnecessary. More ...

Fundamental Digital Logic Gates
All the advanced features of the most powerful computers, such as mulicore and parallel processing are done with digital logic. In this article I explain the fundamental concept of digital logic in simple and clear language so that anyone can understand it. More ...

Area of an Ellipse Calculator
It's easy to calculate the area of an ellipse because it's similar to calculating the area of a circle ecept instead of Pi times the radius squared, its Pi times the long axis times the short axis. More ...

Inkscape Text on Path
One of the most amazing things Inkscape can do, and one of the easiest, is to place text on a curved path. You can even make the text go in a circle. More ...


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