EAB moderator Cody Jarrett has ported over Sega's Sonic the Hedgehog 2 over to the Commodore Amiga AGA, delivering the entire game from the iconic logo to the final credits. This conversion includes all eleven zones, cooperative play with a computer-controlled or second-player Tails, the 2-Player VS mode, and the legendary special stages. Remarkably, the developer built the port by using Anthropic's AI, Claude, to translate the original 68000 game logic from the Sonic Retro community's s2disasm disassembly into C code. Furthermore, the developer ran the original and new code side-by-side using the Unicorn engine to check for identical results. Unlike reassembler’s highly anticipated, purely human-coded upcoming Sonic 1 Amiga port, this Sonic 2 project leans on modern AI assistance, offering a alternative approach to retro development.
Because the Amiga relies on pre-drawn graphics and sampled audio rather than the Mega Drive's hardware-synthesised music and compressed tiles, the port demands significantly more memory than the original 1 MB ROM. The game requires 4 MB of Fast RAM to hold the 2 MB program and the 3.9 MB needed per act, while the 2 MB of Chip RAM handles the AGA dual playfield screens, hardware sprites, and audio samples. Visually, the game utilizes the Amiga's Copper for per-line background scrolling and water effects, alongside the blitter for objects. Meanwhile, the Paula also handles the soundtrack, which has been converted into 4-channel ProTracker modules. Built using tools like Bartman’s Amiga GCC toolchain and the Shrinkler packer, this AI version of Sonic is available to download below.
- Again, I know many of you will think of this as AI slop, but at least we do have reassembler’s upcoming version of Sonic that pushes AI aside for pure human coding :)
- AGA Amiga (A1200 or A4000) with a 68020 or better
- Kickstart 3.0 or later (tested with 3.1)
- 2 MB Chip RAM and 4 MB Fast RAM
- About 20 MB of hard-disk space for the LHA or HDF version
- *It's still a test release, so please report anything you find, with your Amiga's CPU, memory and Kickstart. It has been played on a real A1200 with a Blizzard 030; 040/060 cards and less than 4 MB Fast RAM are untested.*
Links :1) Source - Thanks AmigaFrance for the heads up.
I have possibly found what could be a memory leak. The RAM requirements to launch the game are too high. this makes the music not playing, and the level 2-1 chemical plants won't start, there will be an exit back to WB, with failed level 0D00 : renderer resource (error 0). The main code must be forced to be loaded in fast ram, and i have found a bug that make the game derail when you let the game cycle in the intro and then demonstration mode. It gradually corrupt..... my config is A1200 32mb fast + 68030/50mhz.
ReplyDeleteAnother thing i've notice : the first 2 levels have scrolling stuttering when crossing the waterfalls, otherwise it run 50fps and very good speed. The chemical plants levels have strange slowdowns, depending on the scrolling activated. when sonic scrolls up, it slowdowns, horizontal scroll is fine, diagonal scrolling is very good as well, and very strangely Casino levels play without slowdowns. If you want to see the game running full speed, that's the perfect test level. It plays exactly like the megadrive at the exact same speed.