=============================================================================== ALIENS Hadley's Hope A first-person shooter for the Amstrad CPC 6128 2026 by Devil-System =============================================================================== CONTENTS -------- 1. The Story 2. Requirements 3. Loading the Game 4. Controls 5. How to Play 6. The Levels 7. Enemies 8. Items and Objects 9. Health and Game Over 10. Hints and Tips 11. Technical Details 12. Files on the Disk ------------------------------------------------------------------------------- 1. THE STORY ------------------------------------------------------------------------------- LV-426, 2179. Fifty-seven years after the loss of the Nostromo, the colony HADLEY'S HOPE has gone silent. Its seventy families, its atmosphere processor and its operations block no longer answer any call. You are ELLEN RIPLEY, warrant officer and sole survivor of the Nostromo. You came back with a squad of Colonial Marines. Now the squad is gone, the dropship is wreckage, and the only way out is down: through the colony, into the hive that has grown around the atmosphere processor. Somewhere down there a little girl named Newt is waiting for you. And somewhere below her lies the chamber of the ALIEN QUEEN. Armed with an M41A pulse rifle and whatever magazines you can scavenge, you must fight your way through eight levels: the operations block, the colony quarters, the atmosphere processor, the medical lab, the outskirts of the hive, the colony records and the hive itself. On each level you have to reach the cargo ELEVATOR to the next one. At the very bottom the Queen is waiting. Get away from her. Nuke it from orbit. It's the only way to be sure. ------------------------------------------------------------------------------- 2. REQUIREMENTS ------------------------------------------------------------------------------- - Amstrad CPC 6128 (or a CPC 464/664 with 64 KB memory expansion), or an emulator set up as a CPC 6128 (e.g. WinAPE, CPCEC, Caprice, Arnold, RetroVirtualMachine) - Disk drive (3" drive, Gotek/HxC or disk image in the emulator) - Keyboard; a joystick is optional The game needs the extra 64 KB RAM of the 6128: parts of the 3D engine are loaded into the additional memory banks. It will not run on an unexpanded CPC 464 or 664. ------------------------------------------------------------------------------- 3. LOADING THE GAME ------------------------------------------------------------------------------- Insert the disk (or attach ALIENS.DSK in your emulator) and type: RUN"ALIENS" and press RETURN (or ENTER). The loader first shows the title picture, then loads the game code and the three engine files into memory. After a few seconds the title screen appears. Please note: do NOT start the game with RUN"ALIENS.BIN". Always use the BASIC loader, otherwise the engine files cannot be loaded. ------------------------------------------------------------------------------- 4. CONTROLS ------------------------------------------------------------------------------- Keyboard and joystick can be used at the same time. There is nothing to select or configure. Action Keyboard Joystick -------------------------- ---------------------- ------------------- Walk forward Cursor Up or W Up Walk backward Cursor Down or S Down Turn left Cursor Left or A Left Turn right Cursor Right or D Right Strafe (step sideways) Q (left) / E (right) - Fire CTRL Fire Open a door SPACE, F, RETURN, ENTER 2nd fire Use the elevator SPACE, F, RETURN, ENTER 2nd fire Open a secret wall SPACE, F, RETURN, ENTER 2nd fire Automap (pauses the game) M - Start game (title) SPACE / RETURN Fire (With a one-button joystick the button fires and SPACE opens doors.) Continue (between levels) any key Fire Choose view size (title) 1 / 2 / 3 - Enter a password (title) P, letters, RETURN - Back to the title menu ESC PASSWORD ENTRY On the title screen, press P. "Password:" appears with six dots. Type the password, correct mishots with DEL and confirm with RETURN (ESC cancels). The result is shown in the same line: "Start: LEVEL n" the game will start on that level "Wrong password" the game will start on level 1 You can enter a new password at any time by pressing P again. VIEW SIZE On the title screen, press 1, 2 or 3 to choose the size of the 3D window. The current choice is shown as "View: ...". Key View Window size (pixels) Speed (approx.) --- ----- --------------------- ------------------------ 1 FULL 160 x 200 (full screen) 5 - 6 frames per second 2 2/3 108 x 136 8 frames per second 3 1/2 80 x 104 11 frames per second The field of view is the same in all sizes. The smaller the window, the smoother the game runs. The default is 2/3; the setting is kept until you change it. In the smaller sizes the rest of the screen is filled with a terminal wall pattern, with a black frame around the 3D window. Shooting and using are separate: CTRL / Fire always fires the pulse rifle, USE (SPACE, F, RETURN, ENTER or 2nd fire) opens doors and secret walls and lets you take the elevator when you stand right in front of them. Elsewhere USE does nothing, so no ammunition is wasted. ------------------------------------------------------------------------------- 5. HOW TO PLAY ------------------------------------------------------------------------------- Levels 1 to 7: Find the cargo ELEVATOR and use it. It is easy to spot: a cage door framed with yellow-and-black stripes. Walk up close (about one tile), face it and press USE (SPACE, F, RETURN, ENTER or 2nd fire). You are taken to the next level. Level 8 (Queen's Chamber): There is no elevator here. Your goal is to KILL THE QUEEN. When she falls, you have won the game. You do NOT have to kill every alien. Speed and survival matter more than a body count, but aliens will chase you once you get close, so it is often safer to deal with them than to run. Before each level a short screen shows the level number and your goal: "LEVEL n - Find the elevator" (levels 1-7) "LEVEL 8 - Kill the Queen!" (level 8) It also shows your score, your ammunition and - from level 2 on - the PASSWORD of this level. Write it down: entering it on the title screen (press P) lets you start directly on that level next time (with a score of zero). AUTOMAP Press M at any time to see a map of the level inside a cyan frame. It shows the area around every place you have walked (one tile in each direction); secret walls look like normal walls. The level is shown as a dark blue area, walls in their own colour (panels grey, cocoons and hive walls in their own colours, terminals green, pipes, elevator, doors yellow, vents white). Your position is a yellow arrow pointing in the direction you are facing. Below the map: level number, ammunition and score. The game is paused while the map is shown. Press M, ESC or Fire to go back. ------------------------------------------------------------------------------- 6. THE LEVELS ------------------------------------------------------------------------------- Every level is a 16 x 16 tile maze. Level Name Layout Aliens ----- --------------------- ---------------------------- ----------- 1 Operations Block Offices around a corridor 6 2 Colony Quarters Streets and family flats 6 3 Atmosphere Processor Pipe shafts, switchbacks 6 4 Medical Lab Lab with stasis tubes 6 5 Hive Outskirts Organic caves, cocoons 7 6 Colony Records Archive rows, offices 6 7 The Hive Twisting hive tunnels 6 8 Queen's Chamber Egg-filled cavern 6 + QUEEN Every level also holds medipacks, ammunition and treasure. Some of it is hidden behind secret walls. Goal on levels 1-7: reach the elevator. Goal on level 8: kill the Queen. Your health is fully restored at the start of every level. ------------------------------------------------------------------------------- 7. ENEMIES ------------------------------------------------------------------------------- ALIEN WARRIOR Black, glossy and fast, with an elongated skull, silver teeth and a long tail. Nobody knows how many of them there are. - Takes 3 hits to go down. - Notices you when you come within about 8 tiles and comes for you. - Spits acid whenever it has a clear line of sight - even from far away. The closer it is, the more likely it hits. Walls and closed doors block the acid. - Slashes with claws and tail in close combat (less than one tile). - Every hit takes one unit of your health. - When hit, it flashes acid green and stops for a moment. - It dissolves into a puddle of acid after about 2.5 seconds and leaves a pulse rifle magazine behind (the marines left plenty). THE ALIEN QUEEN Huge, with a wide crested head, extra arms and very bad manners. - Takes 12 hits to go down. - Chases, spits and slashes just like her warriors. - Glows green when hit. - When she falls, she sinks into a pool of her own acid. About 2.5 seconds later the victory screen appears. Aliens cannot pass through closed blast doors. Once you open a door, it stays open, and aliens can follow you through it. ------------------------------------------------------------------------------- 8. ITEMS AND OBJECTS ------------------------------------------------------------------------------- MEDIPACK A white box with a red cross. - Walk over it to use it. - Restores 4 units of health (half of the maximum), up to the maximum of 8. - It is only used if you are injured. At full health it stays where it is, so you can come back for it later. PULSE RIFLE MAGAZINE An olive green M41A magazine. - Walk over it to pick it up: +8 shots (maximum 40). - It is only picked up if your rifle is not fully loaded. - Every alien you kill leaves one behind. TREASURE (CASEY) The head of Newt's doll Casey. Newt will want it back. - Walk over it to pick it up: +500 points. BLAST DOORS Grey doors with yellow-and-black hazard stripes and a red light. - Face the door from close range (about 1.5 tiles) and press USE (SPACE, F, RETURN, ENTER or 2nd fire). - The door slides open sideways in a little under a second and stays open. CARGO ELEVATOR A metal cage door framed with yellow-and-black stripes. - Face it from close range (about one tile) and press USE. - Takes you down to the next level. SECRET WALLS Some walls look exactly like normal wall panels but can be moved: face the wall from close range and press USE. It slides aside like a door and reveals a hidden room. Where they are is up to you to find out. WALL TYPES - Ribbed colony wall panels with a hazard stripe - Hive wall with a cocooned colonist (don't ask) - Computer terminal with green screen and blinking lights - Pipes and red valves - Hive wall: biomechanical ribs - Ventilation grille with a fan (solid) ------------------------------------------------------------------------------- 9. HEALTH AND GAME OVER ------------------------------------------------------------------------------- Your health is shown as a red bar in the top left corner of the screen. The maximum is 8 units. Below it, the yellow bar shows your ammunition (maximum 40 shots, one small block = 2 shots). You start the game with 16 shots; ammunition is kept from level to level. With an empty rifle you only hear a dry click. SCORE Alien 100 points Treasure 500 points Level completed 1000 points Alien Queen 5000 points Your score is shown between levels, on the automap and at the end of the game. The best score (HI-SCORE) is shown on the title screen. HALL OF FAME The eight best players are kept in the HALL OF FAME. If your score is good enough at the end of a game (Game Over or victory), "Name:" appears: type up to 8 letters (DEL corrects, RETURN confirms). The list is then saved to the disk as HISCORE.DAT and loaded again the next time you start the game. Leave the disk in the drive and do not write-protect it if you want your scores to be saved; if saving is not possible, the list is simply kept until the computer is reset. To reset the Hall of Fame to its original entries, type RUN"RESHIGH" (disk must not be write-protected). Then start the game again with RUN"ALIENS". - Each alien hit (acid or claws) takes 1 unit. The screen border flashes red when you are hit. - Medipacks restore 4 units. - Health is refilled to 8 at the start of every level. Press ESC at any time during the game to abandon it and return to the title menu (for example to change the view size). To leave the game completely, reset the computer. When your health reaches zero, "GAME OVER" appears together with your score (and "NEW HI-SCORE!" if you beat the record; see HALL OF FAME for entering your name). Press any key or Fire to return to the title screen and try again from level 1 - or enter a password to continue on a later level. TITLE SEQUENCE AND DEMO MODE If no key is pressed, the title screen changes every 5 seconds: title menu - Hall of Fame - title menu - Hall of Fame - title menu - demo. Any key brings back the title menu and starts the sequence again. The demo is an autopilot that plays through level 1 (opens the door, shoots the aliens on its way and takes the elevator). The title music plays in a loop while the title screen is shown. Press any key, Fire or move the joystick to return to the title screen at once. The demo also ends by itself at the elevator. The selected view size is used. After killing the Queen you get the victory screen: "VICTORY! The Queen is dead! Nuke it from orbit" Press any key or Fire to return to the title screen. ------------------------------------------------------------------------------- 10. HINTS AND TIPS ------------------------------------------------------------------------------- - Keep your distance. Aliens spit acid, but they hit much less often from far away. Use corners and doors as cover. - Your shot hits whatever is in the middle of the screen. Line up the enemy with the centre before firing. - An alien that is hit stops for a moment. Keep firing and it will not reach you. - Save medipacks for later: they are not used while you are at full health. - Watch your shots. Collect the magazines the aliens leave behind. - Use Q / E to step sideways out of an alien's reach while keeping it in your sights. - Lost? Press M for the automap. - A dead end in a straight corridor or an odd single wall block can hide a secret wall. Try USE (SPACE / F / RETURN / 2nd fire). - Open doors carefully. Aliens may be waiting in the room behind. - On level 8, clear out the warriors before you open the doors to the chamber. The Queen needs 12 hits, so you want a full health bar for that fight. ------------------------------------------------------------------------------- 11. TECHNICAL DETAILS ------------------------------------------------------------------------------- Engine - Raycasting engine written entirely in Z80 assembly language. - Full-screen 3D view: 160 x 200 pixels in MODE 0 (16 colours). 80 rays are cast per frame, each ray drawn as 2 pixels wide. - Texture-mapped walls: 16 x 16 texel textures, 9 wall types, each with a light and a dark variant for the two wall orientations (simple lighting). - Compiled scalers: for each possible wall height there is a specialised, unrolled drawing routine. These routines take about 61 KB (including the clipped scalers for the smaller view sizes) and are stored in the extra 64 KB RAM banks of the CPC 6128. They are paged in at &4000-&7FFF while the walls are drawn. - Sprites (aliens, the Queen, remains, medipacks, ammunition, treasure) are scaled with the distance and clipped against the walls per column (depth buffer). - Only changed parts of the ceiling and floor are redrawn, which saves a lot of time. - Sliding doors are handled inside the raycaster: rays pass through the part of the door that is already open. - Movement and animation are timed with the 50 Hz interrupt, so the game runs at the same speed whatever the frame rate. - Frame rate on a standard 4 MHz CPC, depending on the scene: full view (80 rays) about 5 - 6 frames per second 2/3 view (54 rays) about 8 frames per second 1/2 view (40 rays) about 11 frames per second - Selectable view size: the smaller windows are vertically centred so that the normal scalers can be reused unchanged (a wall in a small window looks exactly like a more distant wall in the full window). Only walls that are taller than the small window use extra, clipped scalers (43 for 2/3, 43 for 1/2). Separate ray angle and fish-eye correction tables keep the field of view identical. Sound - Own sound player for the AY-3-8912 sound chip, driven by the firmware's 50 Hz interrupt (frame flyback event). - Sound effects: rifle shot, acid spit, empty rifle, enemy hit, enemy death, player hurt, door, medipack, ammunition and treasure pickup, short melodies between levels, on victory and on defeat. - Title music: a small three-channel tracker plays an original military march in D minor at 125 BPM - lead melody on channel B (centre), octave bass on channel C and marching drums (kick, snare rolls, hi-hat made from tone and noise) on channel A. Other melodies play on channel B, sound effects use all three channels. Graphics - Custom 16-colour palette (firmware colours): 0,0,1,26,3,6,12,15,24,1,11,18,16,13,10,20 - Custom bold character set (96 characters) in classic shooter style, with small capitals for lower case letters. - The title logo is drawn at runtime from the character set: twice as wide, three times as high, with a colour gradient and a drop shadow. - Title picture (TITLE.SCR) shown by the loader while the game loads. Game data - 8 levels of 16 x 16 tiles, stored in memory bank 7 behind the last block of scalers and copied to a buffer when a level starts - Up to 16 objects per level (aliens, medipacks, ammunition, treasure, the Queen) - Player health: 8 units; alien: 3 hits; the Queen: 12 hits - Medipack: +4 health; magazine: +8 shots (max. 40) - Score kept as BCD (in hundreds); Hall of Fame (8 names) saved to and loaded from HISCORE.DAT (80 bytes) - Automap: whenever you enter a new tile, the 3x3 tiles around you are marked as explored (256-byte table); no cost for the raycaster Memory map (main RAM) &0170 - &02FF BASIC loader (MEMORY &2FF) &0300 - &7FFF Game code, tables, textures, sprites &8000 - &8FFF Sound player, view size module, automap, title and password logic, character set data, title logo routine &9000 - &97FF AMSDOS file buffer (while loading the banks and HISCORE.DAT at start-up) &9000 - &96FF Character matrix table used by the firmware (set up after loading) &9700 - &97FF Enemy AI (line of sight, acid spitting), copied from bank 7 when a game starts &9800 - &9BFF Quarter-square multiplication tables (built at start-up) &9C00 - &9CFF Automap: explored tiles &9D00 - &9EFF Buffer for the current level &9800 - &9FFF AMSDOS file buffer when saving HISCORE.DAT (tables are rebuilt afterwards) &C000 - &FFFF Screen memory Banks 4-7 Compiled scalers (SC0.BIN - SC3.BIN); bank 7 also holds the 8 levels Development - Assembled with RASM. - Textures, sprites, levels, font and scaler code are generated by Python scripts, then assembled and written to the disk image. ------------------------------------------------------------------------------- 12. FILES ON THE DISK ------------------------------------------------------------------------------- ALIENS.BAS BASIC loader (start with RUN"ALIENS") TITLE.SCR Title picture (loaded to &C000, palette routine at &C7D0) ALIENS.BIN Main program (loaded to &0300, about 35 KB) SC0.BIN Compiled wall scalers, part 1 (memory bank 4) SC1.BIN Compiled wall scalers, part 2 (memory bank 5) SC2.BIN Compiled wall scalers, part 3 (memory bank 6) SC3.BIN Compiled wall scalers, part 4, and the 8 levels (memory bank 7) HISCORE.DAT Hall of Fame (8 names and scores, 80 bytes) RESHIGH.BAS Resets the Hall of Fame (start with RUN"RESHIGH") RESHIGH.BIN Reset program (loaded to &4000 by RESHIGH.BAS) =============================================================================== Aliens - Hadley's Hope - 2026 by Devil-System ===============================================================================