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Sonic Zx

Posted: Mon Jun 24, 2024 12:57 pm
by Ralf
Long, long time ago there was a project to make a Sonic game on Zx Spectrum.
You can see the archived copy of the website for example here:
https://web.archive.org/web/20050211104 ... oniczx.htm

There was quite a lot of noise and high expectactions around it but in the end nothing came out of it.
Currently this project doesn't have an entry in ZXDB. There is some demo related to it but it's not the same:
https://spectrumcomputing.co.uk/entry/2 ... _Slideshow

Do you think that it should have its separate entry?
If yes, then I have some data related to it that I could upload - mockups, graphics, tunes etc.

Re: Sonic Zx

Posted: Mon Jun 24, 2024 6:34 pm
by +3code
I remember a Greek group looong ago was making something. They released nothing, but we have Toki in the database, so I'm not sure what is the criteria.

Re: Sonic Zx

Posted: Mon Jun 24, 2024 6:47 pm
by AndyC
Do we really want to start creating entries for what was essentially vaporware? I'm not sure filling the database with every random project that gets started is necessarily a great idea.

Re: Sonic Zx

Posted: Mon Jun 24, 2024 8:21 pm
by Ralf

Re: Sonic Zx

Posted: Mon Jun 24, 2024 8:30 pm
by AndyC
I think there's a difference between commercial software that was announced, but not released (ala GTW type content) and just hobbyist projects that were little more than a few graphics and music files.

The former are interesting from a historical perspective, but the latter often amount to little more than "Would it be cool if?" ideas, even utterly impractical ones.

It's a subtle difference, but I don't think we want to go down the route of creating database entries for Tomb Raider ZX or Fortnite ZX just because someone has drawn a mock up screen and wants someone to make it...

Re: Sonic Zx

Posted: Tue Jun 25, 2024 11:12 am
by Lee Bee
It's a database of games, so (for hobbyist projects) graphics and music alone would not qualify as they're still just a concept. But I would be in favour of abandoned games being included when we have access to a playable work-in-progress demo. Technically, the only difference between a playable demo and a short game is the intention to expand it.

Re: Sonic Zx

Posted: Tue Jun 25, 2024 12:01 pm
by Ralf
Okay, I take these answers (and lack of other answers) as "don't make the entry".
So I won't make it.

Re: Sonic Zx

Posted: Tue Jun 25, 2024 12:15 pm
by Lee Bee
One way or another, I'd love to see a Spectrum sonic game. For the record, @Grongy has done his own concept graphics (1 2), I think a great candidate to code it would be @ssmirnov (Sergei Smirnov), plus I'm always eager to do music (1 2).

Re: Sonic Zx

Posted: Tue Jun 25, 2024 12:34 pm
by Ralf
Doing a good Sonic game for Spectrum is very hard. That's why that project never got beyond concept arts.
You probably would have to make some sacrifices here. Either you make it monochrome or you make it move by 8 pixels.

Re: Sonic Zx

Posted: Tue Jun 25, 2024 12:43 pm
by AndyC
Ralf wrote: Tue Jun 25, 2024 12:34 pm Doing a good Sonic game for Spectrum is very hard. That's why that project never got beyond concept arts.
You probably would have to make some sacrifices here. Either you make it monochrome or you make it move by 8 pixels.
That was half the problem, the other half was an ideological one: they wanted to do it "legit" and get Sega to sign off on the project. And, unsurprisingly, Sega didn't care to respond to weird enquiries about making a version of Sonic on ancient, obscure hardware.

Re: Sonic Zx

Posted: Tue Jun 25, 2024 4:01 pm
by Bedazzle
Ralf wrote: Tue Jun 25, 2024 12:34 pm You probably would have to make some sacrifices here. Either you make it monochrome or you make it move by 8 pixels.
Or go for Spectrum Next. :)

Re: Sonic Zx

Posted: Tue Jun 25, 2024 11:32 pm
by Lee Bee
Ralf wrote: Tue Jun 25, 2024 12:34 pm Either you make it monochrome or you make it move by 8 pixels.
8 pixel scrolling is not a problem…

The original Sonic game is a fast game. When Sonic is at full acceleration, it takes background items approx. 60 frames (1 second) to pass from one side of the screen to the other. So, if the Spectrum version were running at 25 fps, then 8 pixel scrolling would actually be slightly slower than the original game (78% the speed, to be precise).

As for how to deal with when Sonic is moving at slower speeds (like when you first start moving from still, or when something slows you down), I've invented a scrolling system that could deal with this…

My scrolling system


1. If Sonic begins moving and he's at the middle of the screen, or beyond the middle, then scrolling will begin (8px speed)
2. At full speed, Sonic moves at the same speed as the scrolling, so his x position will be static
3. If Sonic reaches full speed and he's beyond the middle of the screen, there will be a brief 16px scroll until he reaches the middle of the screen (or slows down)
4. Once scrolling has begun, it continues, even if Sonic slows down slightly or stops. Sonic will just begin to drop back behind the scrolling.
5. If Sonic drops back to 1/3 of the way across the screen, then scrolling stops. This gives him room to get back up to full speed before reaching the middle of the screen again
6. If Sonic turns to face the opposite direction, scrolling direction is flipped and all the above rules apply immediately
7. For vertical scrolling - if Sonic is travelling vertically at full speed, then simply scroll at full screen. Other than this, vertical scrolling should not be too common and should only take place if Sonic's average y position over the last 1 second has significantly changed, in which case begin scrolling toward his current y position