Well this is incredible news, and one I didn't expect for a bank holiday Monday. As a classic gaming icon has made a surprising leap over to the Commodore Amiga 1200 as a highly anticipated work-in-progress demo of Sonic the Hedgehog. Titled as Aonic and released by reassembler, this impressive technical feat ports the blue spinning hedgehog over from the Sega Mega Drive to the Amiga. This project over the many months of development, has captured the attention of Amiga retro gamers eager to see how Sega's flagship title performs on the Commodore A1200 hardware.
The underlying engine relies directly on the original Mega Drive source code, utilizing the comprehensive disassembly published by the Sonic Retro team. Because it shares this foundational DNA, the homebrew port plays identically to its console counterpart, preserving the precise physics, momentum, and speed that defined the 1991 classic. However, because the remainder of the game is still being implemented, certain aspects of the performance and design could still improve or degrade before a final release.
Translating the game to the Amiga required significant engineering adjustments because the two systems are very different pieces of kit, despite sharing a similar 68000-based CPU. Specifically, hardware like the Amiga 1200 struggles with bus contention when moving large amounts of data around—a hurdle that is easy to circumvent when designing an Amiga game from scratch, but highly problematic when porting an existing title at high quality. To overcome this, the rendering engine was heavily optimized and rewritten for the Amiga, resulting in some necessary visual differences while keeping the gameplay intact.
- Stock A1200, 2MB Chip Ram required
From real hardware
ReplyDeletehttps://www.youtube.com/watch?v=tJiz3u7QZFM
NICE ! :)
DeleteGreat work as usual, but I think you should use 2x fetchmode for bitplanes to make blitting faster. Move screen 32 pixels to right to not lose HW sprites. Thats how e.g. Turrican did it to not lose HW sprites with scrolling on OCS, but that was 16 pixels shift only. Or lose the HW sprites and have less sprites for background layer, its unimportant anyway, and even with all 8 sprites, you cant cover whole background layer in 15 colors. Another option is to have less width of screen, like you already have, so 2x fetchmode should be well possible with 288 pixel wide screen.
ReplyDeleteHe *is* using what you call FMODE 2x. This is why the res is 288. He just calls the very same mode FMODE 1, which is the value to put into those bits in FMODE. With FMODE 0 (or 1x) things would really crawl.
DeleteOk thanks for correction, reassembler does it right then. It's still not enough it seems. FMODE 4x would bring only marginal gains, with only 5 bitplanes, and a still narrowed down view from 288 pixels. I removed also my other comment about this topic.
Deleteimpressive!
ReplyDeleteMASTERPIECE!
ReplyDeleteThe effort is impressive and, the results are amazing...
ReplyDeletebut I´m not gonna lie, it´s very frustrating to see how many compromises were made, less horizontal resolution, less colors,inferior parallax layer, menu itens in a pannel instead of an overlay...
Again, it looks amazing, but, just asking for a friend:
If it required, instead of a default A1200, an accelerated one, like a 060 accelerator and enough FastRAM, would it be possible to make it exactly like the Megadrive version?
using the CPU to draw on the screen, instead of relying in the pathetic AGA chipset alone?
Or, was AGA so crap that it was not just a complete disappointment but also it made it impossible to even enhance the system performance even spending thousands of dollars on expensive accelerator cards and not so cheap RAM?
A lot of people considered the AGA chipset a mild disappointment and this is further proof that they weren't wrong, I suppose. Also, to be fair, Sonic was pretty much built around the Mega Drive hardware and really pushes it to its limits. I haven't seen a lot of people talk about the frequent slight framerate drops, but they're definitely there. This is also why playing the original games and Sonic Mania back to back makes Mania feel so much smoother. This has probably been discussed already, but I suppose there are reasons why the AGA version isn't using Dual Playfield Mode? In theory, this gives you a 16 color front and back layer like it is done on the Mega Drive, freeing up hardware sprites for other uses.
ReplyDeleteThis comment has been removed by the author.
DeleteA 1:1 Sonic port is absolutelty possible with AGA if built around a fast CPU. I dont think AGA is pathetic or crap. Yes, it should have been released earlier, but with fast RAM installed it wasnt that bad. The Megadrive will always win when it comes to these kinds of games, because it was a console designed only for games. The Amiga was not a console, but a personal computer. Even 486 PC would have struggled with a 1:1 Sonic port.
ReplyDeleteAt first, I thought this was an update to the 2025 RetroRic Amiga Sonic tech demo.
ReplyDeleteTo be honest, the UI panel in the top and the reduced resolution (288 pixels) are the thing that disapoints me the most...
ReplyDeleteMy humble suggestion, and, again, I follow ALL your videos on Sonic and Outrun and I´m a fan of your work, a hardcore one, counted the days for a new update on your projects...
But, I´d rather have a version with no parallax at all but full resolution and real UI overlay
and, perhaps, the possibility to turn the parallax On/Off for Accelerated Amigas (or WinUAE were probably 99% of us play Amiga games anyway...)
And, I´m not disappointed on you, just that a 1992 700 dollars computer could not compete with a 99 dollars console (megadrive price in 92 according to Google)
Really sad.
I don't get why people in the Amiga community always think it's just "push that litte button, and then you have a completely different version for those who want".
DeleteThese are highly specialized screen setups, where every cycle or DMA slot counts, and it takes weeks if not months to change that.
And yes, a highly 2D specialized 99 dollar console beats an Amiga on this kind of game.
My personal opinion is, that I would not trade off that amazing parallax with a simple HUD.
But you do you.
Of course Amiga 1200 can compete, its far superior to the Megadrive in many ways. The megadrive is a console with specific hardware for making games like Sonic easy to pull off. Any personal computer, including fast PCs from that era would struggle with a 1:1 Sonic port.
DeleteThat doesnt make the Amiga 1200 inferior, it has other strengths that the megadrive cannot compete with.