20211030

File links updated

Due to problems with Google Drive, files have been moved to Github and article links updated.

20200923

AMP16K: Multichannel sound on the ZX Spectrum 16K

A 4-channel beeper engine with support for contended memory. Technical information below.

Download archive (source code, converter, documentation)

20190129

Ninja Gaiden: Shadow Warriors (Jerri, DaRkHoRaCe, Diver4d, 2018)

  • [Critical] Fixed crash when using the grappling hook shortly after the Fire Wheel attack
  • Fixed crouching directions and attacking
  • Fixed controls handling during the lift auto sequences on level 5
  • Removed white screen transitions at sublevel changes
  • Other minor fixes

20180923

Savage (Firebird Software, 1988)

Part One

  • Most of the graphics engine rewritten for speed
  • [Critical] Fixed calling init-time, inexistent code after a Game Over
  • Fixed keyboard polling logic in menu and intermission screens
  • Player character's direction and thrown weapons are reset after starting a new game
  • Fixed the incorrect Part Two password displayed at game completion

 Known bugs

  1. Respawning far from where the player died, attribute artefacts might be left onscreen.
  2. Falling offscreen while in possession of the orbiting bonus weapon leaves it nearby.
  3. Crouching on platforms in the sea of fire leaves the player character unable to move.

Part Two

  • [Unnoticeable] Improved scroller code with correct synchronization
  • Changed the '000' score font after loading to that used in the game
  • Player shots are reset after starting a new game

Part Three

  • Most of the graphics engine rewritten for speed
  • [Critical] Fixed memory corruption problems in the object processing code
  • Lifted the restriction on player's fire rate for balance
  • Player character's direction and shooting FX are reset upon starting a new game
  • Enabled the score routine to display the score
  • The score display is moved to the top of the status panel, shown without flickering

 Known bugs

  1. Bad collision detection due to the fixed oversized hitbox of the player character.
20181102
  • Added tape versions

20180922

Teenage Mutant Hero Turtles (Image Works, 1990)

  • Enabled diagonal movement outdoors, attacking while running
  • Removed restrictions related to jump handling and air control
  • Added vertical background parallax indoors
  • Extra keys listed in the Redefine Keys menu
  • Fixed the character selection cursor when using Kempston
  • Map occlusion and teleport fixes
  • Other minor fixes

Known bugs

  1. In overworld maps, it is possible to get stuck in a wall when moving forward diagonally.
20181102
  • Added .TAP version

20170922

Aline: Colors in sync

Summary

Traditional challenges associated with using multicolor in ZX Spectrum programs include:
  1. Writing precisely timed display code.
  2. Adjusting the synchronization timings by hand to execute it at the right moment.
  3. Keeping the rest of your program from influencing the overall timing.
Aline, the technique presented in this article, aims to get rid of problems 2 and 3 altogether.

20170725

Presto: AY music loader

A ZX Spectrum, Sinclair BASIC compatible tape loader with the ability to play Vortex Tracker II AY music while loading. Supports 128K loading and Pletter-compressed data.

Watch demonstration