Kopec Explains Software

Every modern smartphone and tablet uses a multi-touch user interface. Multi-touch is a relatively recent phenomenon. While the earliest research into multi-touch took place in the 1960s and 1970s, it wasn't until Wayne Westerman and Fingerworks in the early '00s that the first modern multi-touch device was created. And it took the iPhone in 2007 to make it mainstream. In this episode we explain wh...

Human-Computer Interaction is a discipline at the intersection of computer science, psychology, and design. It's about making ergonomic interfaces that sit at the border between the human and the machine. In this episode we explain the field's history, what research in it entails, and its place alongside other disciplines. By the end of the episode you'll gain a general understanding of what HCI i...

A compiler is a program that takes source code written in a programming language and converts it into machine code that a microprocessor can understand. Compilers are sophisticated programs composed of several different phases including (but not limited to) tokenization, parsing, and machine code generation. In this episode we breakdown why compilers are important, how they work, and how they diff...

Tim Howes is a software executive, entrepreneur, investor, and computer scientist who has been at the forefront of many of the most important waves in the technology industry since the 1990s. During his PhD work in computer science, Howes co-created the Lightweight Directory Access Protocol (LDAP), which has become the industry standard means of managing directory information services. In the late...

Are your messages secure? End-to-end encryption protects messages and data from being viewed by anyone but their intended recipients. However, systems that implement end-to-end encryption also prevent law enforcement from intercepting the messages of criminals. In this episode we explain end-to-end encryption and the debate surrounding it as the UK government works to prevent its implementation on...

Blockchain may be one of the biggest tech buzzwords of the decade. But it's not as complicated as you may fear. Pieces of data, blocks, that follow one another chronologically are connected (the chain part) via cryptographic hashes. Each block has a cryptographic hash of the previous block, providing the ability to verify the validity of the chain. We explain the only tricky part of that descripti...

When the iPhone came out in 2007, it totally transformed the mobile industry. But what was so revolutionary about the software in even its first version? For the 15th anniversary of the announcement of the iPhone we talk about the three aspects of the original iPhone's software that set it apart from the smartphones that came before it: its robust operating system, its multi-touch user interface,...

Cookies are primarily used on the Web for two things: authentication and tracking. Although alternatives exist, cookies are the most popular way to provide some state for the stateless HTTP protocol. In this episode we explain what cookies are, how they work, the origin of cookies, applications of cookies, which browsers block "bad" cookies to protect your privacy, first-party versus third-party c...

Software runs on hardware. And of course, hardware has gotten faster over the past few decades by orders of magnitude. So, clearly our software is getting faster. But what do we mean by faster? And why doesn't it always "feel" like it's getting faster? In this episode we explore the underlying factors that sometimes make modern software feel slower, despite actually being faster. Show Notes Comput...

Almost every large piece of software creates log files. Log files record events that happen during the execution of a program. These could be significant routine events or errors. Logs help software developers fix issues. Last week a significant vulnerability was discovered in Log4J, one of the most popular logging libraries. In this episode we explain logging and why the vulnerability was such a...

Logo is an educational programming language that was popular in elementary school computing labs in the 1980s. A generation of programmers began their careers with Logo. Logo is based on turtle graphics, which is centered on commands that guide a virtual turtle cursor around the screen to draw lines. With just a couple very simple commands, learners can begin to draw pictures in code. In this epis...

Amazon is the world's largest online retailer. But they are so much more. They sell cutting-edge consumer electronics like the Kindle and Echo lines, they provide services to ecommerce vendors, they provide consumer streaming services, they own physical stores, and most importantly for their bottom line, they run AWS, Amazon Web Services. In this episode we explain the importance of AWS to Amazon,...

Memory leaks occur when a program allocates memory and fails to free it when the memory is no longer being used. They can cause the memory use of a program to balloon over time, eventually leading to performance problems or a crash. They are a common programmer error, that has been alleviated, although not eliminated, by modern programming languages. Programming languages like C and C++ use manual...

Memory protection is a mechanism for protecting one program from another program, which ultimately protects the user. It stops malicious programs from interfering with legitimate programs, and it stops programmer errors in one program from taking down another. Every time you've been able to force quit a non-responsive application and then go on using your system with the rest of it unaffected you'...

The application process for a job in software development or software engineering typically involves what's known as a "technical interview." Technical interviews are notorious for being intimidating and exclusionary of otherwise good candidates. Technical interviews may involve whiteboarding, live coding, brain teasers, or even take-home projects. In this episode we'll explain what these differen...

Hackers is a cult classic 1995 movie about a group of teenage hackers and their counter culture. The plot revolves around an online battle between the teenagers and a nefarious corporate cyber security expert. In this episode we breakdown how technologically accurate the movie is. What was real, and what was pure fiction? We also review it. Show Notes Ghost in the Wires by Kevin Mitnick via Amazon...

Swift is one of the top ten most popular programming languages in the world by almost any ranking or measure. Yet, it's also a niche language. That seems contradictory, until you know that it's only widely used for building apps on Apple platforms. In this episode, we discuss the history of Swift, what makes it unique, and where it's been going. Show Notes Episode 11: What is a Programming Languag...

Last week a journalist in the St. Louis Post-Dispatch reported on a vulnerability they discovered in the Missouri Department of Elementary and Secondary Education's website that exposed the social security numbers of individual educators. The social security numbers were being exposed in the public facing HTML of the site, making them easily accessible to anyone with a web browser. The journalist...

Facebook's been in the news again, and as usual it's not a positive story. In this episode we dive into some of Facebook's financial statistics from their most recent quarterly filing with the SEC. We then talk about their business model and how your use of Facebook plays into it. We discuss some of the inputs into Facebook's algorithm, and how the data points you generate for Facebook are used to...

Last week marked the tenth anniversary of the death of Steve Jobs. We discuss his legacy and how he inspired people in the tech industry. David also tells the personal story of his Steve Jobs fandom. Show Notes Episode 16: The Personal Computing Revolution Episode 29: Why was the Original Macintosh Significant? Books About Apple and Steve Jobs via David's Blog Becoming Steve Jobs by Brent Schlende...

Objective-C was developed nearly contemporaneously with C++, yet it never achieved the same widespread level of industry acceptance. Both languages attempted to add object-oriented features to the C language, but they went about doing it in very different ways. Objective-C is a superset of C, marrying a thin object-oriented layer inspired by Smalltalk on top of the venerable C language. Today, Obj...

Open source does not mean non-commercial. We start this episode by dispelling the common myths amongst the general public about the relationship between the business world and open source software. We then get into the many different business models that open source software companies use to make money. We cover six different business models, ranging from selling services to using your open source...

Last week, influential British inventor and entrepreneur Clive Sinclair passed away. Sinclair invented some of the first slim calculators, handheld televisions, and digital watches, but he is perhaps best known for being one of the pioneers of the British personal computer industry. In the early 1980s his company, Sinclair Research, developed the hot-selling and widely cloned ZX80, ZX81, and ZX Sp...

Firewalls protect computers and private networks from threats originating across the wider Internet. They come in both hardware and software flavors. They ensure unwanted network traffic is turned away or dropped and that legitimate traffic is only routed to the appropriate application. They work by both simply blocking ports and by analyzing packet data. Windows has had a built-in firewall since...

Every hardware peripheral connected to your computer is powered by a device driver. A device driver sits between the operating system and a hardware device. It speaks the language of the hardware. It understands its commands. It's a point of translation and control. In this episode we explain what device drivers do, why they need to be managed, and how they differ from firmware. Show Notes Episode...