SYSRA: 8086 Assembly Platformer

• SYSRA is a modular platformer engine written entirely in 8086 assembly language. It is built for maximum control and low-level optimization, simulating modern gameplay systems under the extreme constraints of real-mode DOS programming.

• SYSRA is more than just a game—it is a fully custom, extensible engine with robust subsystems and a complete pipeline for asset creation, rendering, and gameplay logic.

• SYSRA was originally made in Unity for the GMTK 2024 game jam and has since become one of my most popular games. The game's lore takes place in the 80s, and to make the experience more accurate, I decided to remake it in 8086 assembly. I also created a prequel to the game to explore more of the story.

---

Playable Demo

You can try out a playable demo of SYSRA here:
Playable Demo

---

Engine Architecture Overview

• Modular Architecture
  Each engine subsystem (input, physics, rendering, etc.) is designed independently and can be modified or reused without affecting the rest of the system.

• Player Movement System
  Handles directional input, jump logic, variable acceleration, and velocity clamping. Built to feel tight and responsive under low frame rates.

• Player Physics
  Implements gravity, fall speed, and inertia using simplified physics appropriate for tile-based collision.

• Player Collision System
  Pixel-precise collision detection with the level tilemap. Prevents overlapping tiles and triggers reaction logic.

• Entity Collision
  General-purpose collision system that supports interactions between multiple object types (player, enemies, spikes, etc.).

• Entity System
  Modular system for game objects. Supports custom logic, animation states, and condition-triggered behaviors.

• Scrolling Level System
  Supports side-scrolling of large tilemaps by updating only the visible region. Efficient memory paging and VRAM transfers.

• Rendering System
  Uses a software frame buffer with double-buffering support. Optimized draw calls for sprites and tiles.

• 1-Bit Sprite Animation
  All sprite graphics are 1-bit encoded and animated using frame index logic. Each sprite is 16×16 pixels.

• Frame Buffer & Swapping
  Back-buffer rendering with manual page flipping to ensure smooth, tear-free display.

• Checkpoint System
  Allows the player to respawn at designated points. Each checkpoint stores position and game state flags.

• Custom Tilemap Support
  Tilemaps are generated from PNG files using an external Python tool. Levels support special logic tiles via a color-coding system.

• Optimized for Size and Speed
  All code is written with performance and minimal memory usage in mind. Built to run on real 8086 hardware or accurate emulators.

---

Requirements

• Assembler: MASM or NASM
• Emulator: DOSBox, 86Box, or real hardware
• Python 3.6+ for asset conversion
• Image editor like Aseprite or GIMP for creating sprites and levels

---

Getting Started

1. Write or update a level PNG or sprite PNG in Sprites/.
2. Run level_converter.py in the LevelEditor directory to convert assets to .ASM format.
3. Assemble the .ASM files using your preferred assembler.
4. Run in DOSBox or another 8086-compatible environment.

For more details on how the level editor works, check out:
LevelEditor.md

---

Author

Created by Shri Hari (TanPi)
A game developer with a passion for low-level systems, performance engineering, and full control over every pixel and bit.

---

Special Thanks

A big thank you to Leonardo Ono for providing the keyboard.asm input handler, which was used for the input system in SYSRA.
GitHub Repository

Thanks to Kenney for providing the art assets.
1-Bit Platformer Pack