Test Release 6/23/25

Sonic 1 C Port - Native PC version demonstration
Designed for Windows x64

I'm calling this a public alpha. This isn't a major version, and there will be bugs/missing features. Widescreen is still in the middle of being worked on, and is broken in most things outside normal levels. Labyrinth Zone still has lots of graphical issues when the surface of the water is onscreen. However, aside from that, the game is fully playable from start to finish. It's based on revision 1 as played off a Japanese Mega Drive, so the level select code is up, down, down, down, left, right, a+start.

Setup:
Take a Sonic 1 ROM (must be revision 1) and place it in the same directory as the game. Name the ROM file "sonic1.bin".
Double click "Play Sonic 1.bat" to play the game at the original aspect ratio.
Double click "Play Sonic 1 (Wide).bat" to play the game in an experimental widescreen mode.

Controls:
Arrow keys: Dpad buttons
A key: A button
S key: B button
D key: C button
Enter/return: Start

Some goodies:
F1 to reset the game
F9 to take a screenshot (saves in the game directory as "screenshot.png")
F10 for "debug pause" (pauses the entire engine, even if you can't pause ingame)
Hold backspace to fast forward

Shader demonstration:
Number 1 key: Reset background shader to default
Number 2 key: Apply blur filter on background (runs slow on my machine, ymmv)
Number 5 key: Reset fullscreen shader to default
Number 6 key: Apply CRT/NTSC filter to screen

I hope you enjoy the culmination of all my work so far.
- Amy Farbright

Initial Release

With this release, all ~25,000 instructions of code present in the original ROM have been successfully reimplemented in C. The game is now fully playable from start to finish. There are still a few issues, such as the level select screen hiding behind the title screen banner, and the lack of horizontal blanking support (for changing the water palettes). Otherwise, everything works.

A REV01 ROM of the original game is required, for reading data from it. Place it in the same folder as the executable and name it s1built.bin.