Commodore 64 Full Game in Assembly Language - DREADCASTLE C64: Build a Complete C64 Vampire Adventure in Assembly for the Commodore 64 (code&books)

Build a complete Commodore 64 game in assembly, one playable step at a time.

Count Dracula is away at the annual Monsters' Convention, and Tom Darkfang's werewolves have taken Dreadcastle. His grandson Oscar, a small vampire still learning to fly, wakes at midnight in the Village of Mortals, miles from home, and the night is short. Dreadcastle is an original side-scrolling action adventure for the Commodore 64, and this book shows you how to build it yourself, from the first byte on the screen to the finished game with its music, its boss fight and its dawn.

The complete game is yours. A companion repository on GitHub holds the full source code of Dreadcastle under the MIT license: the finished game, the thirteen steps of the book, 37 ready-made experiments, the automated tests and the tools. The game is also there ready to play, as a PRG file and as a 1541 disk image. The address is printed in the book.

What you will build

• Eight levels that scroll smoothly both ways, from the Village of Mortals to the Throne Tower, drawn from packed maps of metatiles
• A young vampire who walks, jumps higher the longer you hold the stick, and turns into a bat that flies on beats of its wings and eats moths for energy
• Heirlooms, lanterns, gates and a night that runs out at dawn, with a HUD for health, energy, night and a six-digit score
• Eleven kinds of enemy that walk, fly and pounce, the Count's staff to strike them, and hazards from brambles to fire
• A boss fight against Tom Darkfang, a werewolf made of four sprites, twice Oscar's size
• Original SID music, jingles and fifteen sound effects, with a MUSIC, SOUND FX or SILENT menu, a title screen, victory and dawn
• The finished program on a 1541 disk image, its loading time measured

How this book teaches

• No assembly experience needed. Every instruction is explained the first time it is used.
• Thirteen playable steps. Each is a complete program cut from the finished game, so nothing you learn is thrown away later; its size and SHA-256 fingerprint tell you that you built exactly the program in the book.
• Real code, real screens. Every listing is checked line for line against the source you download, and every screen of the game in the book was captured in the VICE emulator, nothing drawn or retouched.
• Make it yours. 24 guided experiments change speeds, colours, damage, music and words, with safe values and the way back.
• Where it breaks. 13 classic mistakes made on purpose and explained.
• Measured, not guessed. Cycles, memory and loading time are measured in the emulator, and automated tests compare every frame of play with a model of the game.
• Questions with answers, a reference chapter on reading and checking the whole game, a glossary of 102 terms and an index.

Inside the book

Your workshop · Memory and the VIC-II · The level on screen · The raster and the HUD · Smooth scrolling · Oscar walks · Jumps and solid ground · The bat · Heirlooms, the gate and the night · The enemies · The Count's staff · Packed levels and the castle · Tom Darkfang · The fight with Tom · The SID and the music · States, title and menu · The tally, dawn and victory · Effects, jingles and the disk · Reading and checking the game · Glossary and index

What you need

A Windows PC and three free programs: the 64tass assembler, the VICE emulator and Python. The game is written for the PAL Commodore 64 and was tested in VICE.

Dreadcastle is the third volume of the C64 Game Manual Series, where every book is independent and brings a new original game to life. Start the emulator, wake Oscar at midnight and get him home before dawn.