Retro Programming

Xorshift is a simple, fast pseudorandom number generator developed by George Marsaglia. The generator combines three xorshift operations wh...

A project I'm working on needs a fast square root but I couldn't find anything suitable online. After implementing several versions ...

A flood fill is a graphical algorithm to colour an area of screen bounded by pixels of another colour. The scanline technique is a fast, sta...

While attempting to write a game in 256 bytes I needed a routine to draw lines, but Bresenham's line algorithm weighs in at approx ~120 ...

Langton's Ant is an automata which creates a complex pattern by following a couple of simple rules: If the ant is on an empty pixel,...

A few days ago I coded The Matrix digital rain effect, a fictional representation of the code for the virtual reality of The Matrix. The tec...

The Mandelbrot set is a fractal which iterates the equation z n+1 = z n ² + c in the complex plane and plots which points tend to infin...

For years I've been using the following simple code to reverse the bits in the A register by rotating the bits left out of one register ...

A few years ago I submitted a couple of type-in programs ( C-Curve and Curtains ) to Your Sinclair and they featured in the penultimate is...

Undocumented instructions were common on early processors. A few would crash the computer ( HCF - halt and catch fire) while others had str...

The RSSB virtual computer has a single instruction, reverse subtract and skip if borrow. Each instruction has one operand, a pointer into m...

In contrast to the ever increasing memory available, a number of programmers are choosing to demonstrate their coding prowess by squeezing a...

Forget about fancy algorithms and data structures. If you want respect as an 80's hacker, follow these simple tips. Never get caught set...

More often than not, infinite loops are created by programming errors and are quickly dealt with. In sympathy for this highly persecuted gr...