Sinclair ZX Spectrum

Production-ready patterns for Sinclair ZX Spectrum development

12
Patterns
5
Categories

Rendering

5 patterns
Rendering beginner

Attribute Writing

Write colours directly to attribute memory for fast, flicker-free graphics without touching pixel data.
Rendering beginner

Character Printing

Print ASCII characters to the screen using the ROM character set. Direct display file access for fast text rendering.
Rendering beginner

Numeric Display

Convert a number (0-99) to two ASCII digits and print them. Essential for scores and counters.
Rendering beginner

Progress Bar (BASIC)

Horizontal progress bar with colour thresholds — blue through yellow, red, to white. Useful for health, temperature, or timers.
Rendering beginner

Seven-Segment Digits (BASIC)

Draw large seven-segment display digits using PLOT/DRAW. Cell-aligned with 1px outline. 10 DATA strings define all digits 0-9.

Input

1 pattern
Input beginner

Keyboard Reading

Read the ZX Spectrum keyboard matrix by polling I/O ports. Simple, efficient, and no ROM routines required.

Audio

1 pattern
Audio beginner

Sound Beep

Generate a simple beep or tone by toggling the speaker bit. Rising or falling pitch for feedback sounds.

Physics

1 pattern
Physics beginner

Grid Movement with Bounds

Move an entity on a grid with boundary checking. Prevents moving outside the play area.

Framework

4 patterns
Framework beginner

Game Loop (HALT)

Frame-synchronised game loop using the HALT instruction. Locks to 50Hz for consistent timing across all Spectrums.
Framework beginner

Screen Frame (BASIC)

Draw a 1-cell border around the play area with title and footer bars. The standard game screen layout.
Framework intermediate

State Machine Loop

Organise game flow with distinct states (title, playing, game over). Clean separation of game phases.
Framework beginner

Text Utilities (BASIC)

Centre text on any row and clear rows — two tiny subroutines used in every BASIC game.

Other Platforms

Commodore 64 5 patterns Nintendo Entertainment System 6 patterns Commodore Amiga 7 patterns Atari ST 0 patterns BBC Micro 0 patterns MSX 0 patterns Amstrad CPC 0 patterns Commodore VIC-20 0 patterns Sega Master System 0 patterns Cross-Platform 6 patterns