Computing Journey

Created May 26, 2025 (Today)•Updated May 26, 2025 (Today)

Computers used to be so exciting.

Below is an ongoing attempt to record my experience with early computing. I sometimes forget that I had a unique journey given the time that I started interacting with computers.

Rendering & Display

  • Color quantization - Reducing color depth for displaying images with limited colors.
  • Dithering algorithms – Floyd-Steinberg, Bayer matrices, ordered dithering (you've started this one).
  • Scanline rendering – Simple technique for filling polygons or images line-by-line.
  • Blitting – Copying image buffers efficiently (used in games and early UIs).
  • Sprites and Tilemaps - Essentail in 2D game engines for memory and efficiency.
  • Palette cycling – Used to animate water, fire, or gradients without redrawing.
  • Halftone

Image & Compression Algorithms

  • JPEG – DCT, quantization, zig-zag, Huffman coding.
  • GIF – LZW compression, palette limitations, transparency.
  • PNG – Lossless compression using DEFLATE, Paeth predictor, and alpha channel.
  • BMP – Simpler, raw representation, but worth comparing for how uncompressed formats work.
  • TIFF – A deep rabbit hole: optional compression, metadata, used in scanners and high-end imaging.
  • MPEG-1 – Compression via motion estimation, DCT, keyframes (used in Video CDs).
  • Fractal Compression

Color Spaces

  • YUV / YCbCr – Used in video compression.
  • Indexed color – Key for early image formats (GIF, PCX).
  • sRGB
  • CEILAB
  • https://observablehq.com/@mbostock/cosine-color-schemes?collection=@mbostock/color
  • https://observablehq.com/@mbostock/lab-and-rgb

Random Number Generators (RNGs)

  • Linear Congruential Generator (LCG)
  • Mersenne Twister
  • Xorshift
  • PCG
  • Middle Square Method – A charmingly flawed early PRNG (not good, but historical).

Algorithms & Math Fun

  • Bresenham’s line/circle algorithm – Low-level pixel plotting before antialiasing.
  • Flood fill – Used in MS Paint and old drawing programs.
  • Z-buffering (early 3D) – A key idea before GPUs could handle it in hardware.
  • Painter’s algorithm - Sort polygons back-to-front and draw them in that order. Simple and intuitive, but can fail with overlapping geometry.
  • Scanline polygon fill - Used to efficiently fill concave or complex polygons. A key step in early software rasterizers before GPUs.
  • Binary Space Partitioning (BSP trees) - Used heavily in DOOM and Quake to efficiently render indoor 3D spaces by splitting the world into convex regions.
  • Backface culling - Don’t render triangles whose normals face away from the camera. Greatly improves speed and clarity in 3D scenes.
  • Raycasting (2.5D) - Used in Wolfenstein 3D. Instead of full 3D, it shoots rays from the player’s view and finds wall hits on a 2D map, simulating depth.
  • Ray–box and ray–triangle intersection - Core to early 3D picking, selection, and collision detection. Often used in editors or ray-traced previews.
  • Digital Differential Analyzer (DDA) line algorithm - A floating-point alternative to Bresenham; simpler to implement but slower. Useful for raycasting and grid traversal.
  • Barycentric coordinates - Used for point-in-triangle tests and interpolating vertex attributes (colors, UVs) inside a triangle.
  • A and Dijkstra’s algorithm* - Used for AI pathfinding in grid-based games (e.g., tile-based RPGs and RTS games).
  • Marching squares / marching cubes - For contouring bitmap data (used in terrain, fluid, and volume visualization). Marching squares was popular in 2D terrain games.
  • Perlin noise / Value noise - Used for natural textures and terrain generation in early procedural graphics.
  • FFT / DCT

Text & Data

  • Run-Length Encoding (RLE) – Simple but effective for fonts, bitmaps, and cursor icons.
  • Huffman Coding – Foundational to many compression schemes (ZIP, JPEG).
  • Dictionary compression – Like LZ77, LZ78, basis of ZIP and GIF.
  • ASCII / ANSI art – Not compression per se, but early ways of representing visual data in limited media.

Display Technology

  • VGA
  • EGA
  • Mode 13h (320×200 256-color mode) – Used in DOS game graphics.
  • Text mode graphics – ANSI art, code page 437, “code graphics” via box-drawing characters.

Systems / Storage / Misc

  • Filesystem structures – FAT16/FAT32 layout, cluster mapping.
  • Checksum algorithms – CRC32 (used in ZIP, PNG), Adler-32 (used in zlib).
  • Sound encoding – WAV PCM encoding, MIDI file structure, MP3 psychoacoustic compression.

Programming & Dev Tools (Old-School)

  • Turbo Pascal / Turbo C – Blazingly fast compilers with tiny IDEs, great for learning.
  • Borland Delphi – Object Pascal IDE for Windows GUI apps, ahead of its time.
  • Borland C++
  • Visual Basic 6 – Let a generation of kids and sysadmins build real GUI apps.
  • WATCOM C++ – Used to build DOOM and other legendary games.
  • Assembly (MASM/TASM) – For those who dipped into the BIOS or demo scene.

Early Games

  • Commander Keen
  • Wolfenstein
  • Doom
  • Prince of Persia – Rotoscoped animation marvel.

Grab Bag

  • Demoscene
  • Pixel Art
  • DirectDraw – Predecessor to Direct3D; used for 2D game rendering in Windows.
  • 3D Studio Max
  • Dot Matrix Printers
  • 286/386
  • The turbo button
  • Tricks of the Game Programming Gurus book
  • QBasic / GW-BASIC – Early programming environments.
  • HyperCard – Mac-only app builder using cards and stacks (precursor to the web?).
  • AOL/Prodigy Dial Up
  • Netscape Navigator
  • Y2K Bug
  • Napster
  • Homestar Runner
  • WinAmp (“It really whips the llama’s ass”)