Appears On
A two-author machine code hack from 1985 that rewrites the system font in RAM to produce genuinely bold characters — toggled on or off at runtime with a single POKE.
A Blackjack game with PLOT/DRAW card graphics and UDG suit symbols.
A hardware port-polling routine detects incoming telephone calls and waits for a persistent off-hook signal before triggering your own answer code.
Load any screen image and watch this clever machine-code routine slice and enlarge it into an eight-strip, 21-by-25.5-inch poster — automatically printed in one run.
Enter a bounce count and watch a pixel ricochet across the full screen, with distinct beeps at each wall — stopping exactly when you say.
A Breakout-style demolition game that drops a ball through coloured brick rows, complete with splash damage, a high score, and direct font manipulation for the scoreboard.
A calendar generator using Zeller's congruence calculates the correct starting weekday for any month from 1752 onward, with clever PEEK tricks to manage column-based layout.
A tape cataloguing utility that reads file headers directly from memory and logs type, name, size, and load address — all printable and saveable for later review.
A machine-code powered tape cataloger that reads headers from a running tape, identifies file types and names, and estimates their physical position automatically.
Type any word up to 10 characters and watch it redrawn pixel-by-pixel as a magnified outline — a clever trick using POINT and DRAW.
A practical checkbook reconciliation tool that tallies outstanding checks and deposits, then prints a full statement of account on paper alongside the screen output.
A ten-image clip-art menu lets you PLOT, DRAW, and CIRCLE flowers, bees, valentines, and more — even layering multiple images on one screen.
A self-advancing digital clock that chimes every quarter-hour with distinct melodies and renders digits by bit-reading the ROM font with PEEK.
A short machine-code routine transforms the built-in character ROM into a bold double-thickness font, then saves the 768-byte result to tape for use in your own programs.
A clever wheel-factorisation algorithm tackles numbers up to 4 billion, working around floating-point limitations with a custom large-number printer.
A self-relocating machine code routine POKEs itself into RAM, fills the screen with text, then fades the entire display to black in a smooth animated effect.
A mesmerising shrinking geometric pattern built from just four DRAW commands, cycling through two ink colours as it spirals inward iteration by iteration.
A machine code–assisted tool that intercepts and decodes tape header blocks, revealing file type, filename, length, and start address for any loaded tape.
A menu-driven hydrology suite that calculates watershed slopes, draws drainage maps, prepares unit hydrographs, and fits lognormal distributions — all with embedded machine code.
A three-module hydrology toolkit that computes rainfall distribution, unit hydrograph convolution, and reservoir storage-routing functions — all driven from a single numeric menu.
This drawing program builds a famous geometric paradox on screen step by step, complete with randomized sound effects, before revealing its impossible identity.
A tiny 25-byte machine code routine slots itself just above RAMTOP and returns real-time two-key keyboard state — callable from BASIC with a single USR expression.
A full Simplex Method solver that handles mixed constraints, artificial variables, and Big-M penalties — printing the complete tableau at every iteration until the optimal solution is found.
A full machine code monitor lets you examine, edit, enter, save, and run memory—complete with hex/decimal toggle and Z80 scroll routines POKEd in at startup.
A compact 34-byte machine code routine scans your system's memory map and reports what's installed — all launched from a tiny BASIC loader.
A pulse-dialer and auto-launcher that drives a phone line through the expansion port, detects a carrier, then hands off to a machine-code terminal — all in BASIC.
A time-series moving-averages program that handles even and odd periods, computes centred averages, and lets you chain multiple smoothing passes interactively.
Enter any number from 3 to 30 and watch every vertex pair of a regular polygon get connected, revealing intricate geometric star patterns built from pure BASIC trigonometry.
A financial analysis tool that computes Net Present Value and Internal Rate of Return for multi-period investments, complete with iterative IRR search and sensitivity analysis.
Enter a line count and toggle OVER mode to draw radial spoke patterns that can either build up or cancel themselves out on screen.
A mesmerizing random-line drawing program that pairs every stroke with a pitch-varying beep, using XOR pixel mode for an ever-shifting interference pattern.
An interactive PSG register editor that reads, displays, and writes all 15 sound chip registers live — showing binary and decimal values simultaneously.
A Z80 machine code renumbering utility packed into 48 hex DATA strings rewrites every GO TO, GO SUB, and RESTORE reference throughout your BASIC program automatically.
A compact flood-risk calculator uses a classic probability formula to determine how likely a once-in-a-century event is to strike within any chosen time window.
Enter any byte value and watch it fill every pixel and every colour cell on screen — a hands-on tool for understanding display memory layout.
This clever font utility installs 80 bytes of machine code to let any BASIC program switch between Regular, Bold, Modern, and Italic type styles with a single GOSUB call.
A clever pixel-scanning routine reads a text banner and "shoots" each lit pixel down the screen with sound effects, creating a unique animated title display.
A pure-BASIC geometric spiral built from trigonometric rotation and scaling draws an intricate hexagonal pattern — ported from Apple II code published in Creative Computing, February 1984.
A sine wave clipped into a square wave is graphed live on-screen, complete with labelled voltage axis and real-time readouts updating with every plotted point.
Enter an elevation angle and watch your shell arc across the battlefield — but can you calculate the range before your target escapes?
A clever 20-byte machine code routine turns the computer into a live tape signal relay, letting you duplicate cassettes with just two recorders.
A time-series forecasting tool that automatically finds the best exponential smoothing constant by comparing eleven alpha values against your observed data.
Draw spirals, polygons, and abstract patterns with this turtle-graphics engine driven entirely by angle, step length, and an optional growth increment.
Watch a triangle smoothly morph into a square across 20 interpolated frames, driven by a machine code dual-screen buffer that eliminates flicker entirely.
A complete BASIC word processor with word-wrap, tab stops, insert/delete, and cassette save/load — all packed into a single string-array document buffer.
A public-domain, tape-saveable word processor with word-wrap, tab stops, 64-column display support, and a two-level command system crammed into pure BASIC.
A flashing Christmas card draws a PLOT/DRAW tree, scatters UDG baubles, then loops through three carol melodies with randomised ornament colours each time.
Incomplete implementation of figForth.
