pouët.net

Would be cool to have some information, specifications. At least in the INFO file. It looks great, but was it challenging? Is it just "a port" ;)? Is it a final version, or just a v1.0234...?
From the screeny, looks so gorgeous! Color-wise, it reminds me Sega SMS capabilities

Nice screenshot. Platform thumb up!
Please, upload some .nfo and tell us more.

Information on the team website, they didn't really have a README or NFO file:

https://www.wide-dot.com/sonic2.html

So, they are working on a development kit for Thomson machines, which generates a lot of unrolled code for highly optimized display. As a result this requires a machine with either 512K RAM or using the Mégarom to run it from cartridge.

Currently only the first level from the game is available.

The ingame graphics use only even scanlines for the background to speed up things (half the work for scrolling the whole screen).

The machine doesn't have a soundchip 'only a beeper and a DAC that needs a lot of CPU), so this games supports sound only using external extensions (SN76489 and YM2413, to play the original Megadrive music). Otherwise it will be silent.

is this a project by sceners?

Would be interesting to see it on the real CRT.


Good point Sen.
Once, in the past, I added some SMS games, demos. But, TBH, I did not know whether they were, let's say "real" sceners or just real enthusiasts. Never seen any SMS demo-like thing from them (only from my demo-fellow Psidum).

BTW. Thanks Pulko for your kind answers =)

What is your definition of sceners?

At least one of the team members has an account on pouet.net.

The Thomson scene is very largely french-speaking and not really into demoparties. The development for this was done with some occasional help from people on Thomson discussion forums, including members of PULS (most well known Thomson demogroup, I'd say?). As far as I'm concerned, this is part of the Thomson scene.

The code is somehow a direct translation from 16bit 68000 instructions (80,000 lines of ASM) into 6809. Not all is present yet. It will take time to convert that many lines of code. Maybe it will not make it through. Sonic2 mainly helps writing and optimizing the game-engine.

On my side, I helped a bit with a few set of low-level optimisations at some specific places spotted by my profiling too which provided few extra % of speed, but the main ones are in clever rewriting of some complex algorithms like animated objects, objects collisions, etc. There is still some optimizations to work on.

Overall this game engine perform way better than I have expected (~80-90ms/frame at the moment).

A debugging tool has been added to the project. It monitors the memory of the emulator running the game engine and can display in real time it's internal state. The following video shows the allocations of objects while Sonic walks (rushes?) through the first level for instance: https://youtu.be/GDq_b3KsrZQ