Spectrum Computing

Here we go, I'm back, and I've built on my 4px scrolling attribute engine I demo'ed in Jan. I've essentially treated the 48K as a console and absolutely hammered the attribute layer as a tile bank. Keys O, P, M. http://newcastlephotoarchive.org.uk/48kbro/bro4.png http://newcastlephotoarchive.org.uk/...

Thank you! I've finished hard coding the sprites now with ASM lookup tables and I think they are as fast as they can be, so now it's just this attribute copy to get working as fast as possible. The rest of the code is really fast, using the attributes as a tile map is speedy! I'm also coding a super...

It only has to copy the attributes, there is no pixel data, that's all saved for the sprites. The screen is set up with a chessboard like image which is manipulated to get the scrolling. So a copy of 570 bytes. I've written my own sprite routines, and I'll come on to those later, as I know there is ...

Do you have 2 copies of the tiles you need to draw as well then (I'm guessing so). How many different combinations are there for 2 tiles next to each other per frame? If there are only 8 possibilities you could do a Joffa Cobra style thing of emitting a series of push and exx instructions per row u...

Since you are scrolling 4 pixels at a time do you have 2 copies of the map attributes per level (one set for offset by 0 pixels, another for 4 pixels)? That would definitely help if you aren't already doing that and can spare the memory. Yes there are 2 copies which are generated on level boot, it'...

Ah right, I suspected people were doing this unrolled. It just eats in to the RAM, but I think I've got enough space left, plus I can move some of the non-in game graphics in to low RAM. I can probably free up 2kb or so, and I'll give this a go... here is where I find out this is exactly how the com...

Also make sure what you are copying is in non-contended RAM (it's fine to store level data in contended RAM but then copy the data for the current level into a current level buffer in non-contended RAM at level init time - you can compress the level data as well if you want and decompress into non-...

Ah I see, I didn't know a 16byte copy was possible! Full screen :D I'm doing a 'wait vbl' by writing bright black to the bottom of the screen and watching for it, then making that my 'halt' It gives me more time to do things (I'm told this is a better technique than halt, but maybe I'm wrong?). I do...

Hi everyone, you've probably seen my mario/sonic game: https://toastyfox.com/zx/sonic.html I'm trying to get the attribute copy code down to as fast as possible, in that demo I just used: address=0x5840-31; for( p=scx; p<21+scx; p++ ) { memcpy( address, bgi4+q+timestable[p], 30); address+=32; } And ...

I had a go through this, thanks. There was a bizarre way to get to the top of a tree early on, but later, I knew I wouldn't get all of the items :D https://www.youtube.com/watch?v=otjm5q7nc3I Ha it's funny seeing someone else play it, getting up the tree is indeed a bug I'd not seen, I forgot to ma...

You might be right, I am only just learning how to mix them together in 2024 because I have very little to go off from the past...

I think if balanced right it can work for a very fast, very colourful scrolling game. I just keep trying different things until it looks good.

Looks cool - 4-pixel scroll is very smooth-looking. 8-) Only thing I found is that it feels like Sonic style momentum (and style) but the level I played seems to require Mario-style precision. It looks good but I found the controls a bit tricky. I had about 10 goes and couldn't get past the tube/wa...

So, this is what I came up with after my learning curve from making Super Minimal Bros. (super sonic bros. is not necessarily the final name for this) I wanted to make a super fast scrolling Mario/Sonic mashup on the 48k (because that's what I had as a kid!), and the 48k never got games like this. H...

Thanks guys, I'm just reading up on the best way to store level data in terms of reading/writing to it (why not write to it, we have RAM after all, this isn't a console 😅). I apologise if I end up asking some dumb questions, I was barely alive during the spectrum era, but I love how simple the machi...

Hi, Yes, if it can handle 50 fps or so. I've got sprites in my demo now, and you can run around the first level of Sonic, which I spent more time writing a converter for than writing the engine for this :lol: The way I'm doing 4x8 means it takes hardly any CPU to update the screen, it's a decent tra...

Have you looked at Ringo? https://spectrumcomputing.co.uk/entry/38916/ZX-Spectrum/Ringo Source code available on GitHub https://github.com/DenisGrachev/Ringo-8 Yes, I know about Ringo, but it does not work on the 48k which is my target. It's the computer I had, and I want to push it to its limits. ...

I've uploaded a demo of my Sonic game, it's absurdly fast using the 4x attribute trick I wanted to try.

https://toastyfox.com/zx/sonic.html

Super Sonic Bro' coming soon...

I've uploaded a demo of this working, it's absurdly fast and this is with a wait VBL.

https://toastyfox.com/zx/sonic.html

Will keep you updated thank you for all the ideas, I feel 'Super Sonic Bro' might be coming sooner than I thought

So I'm trying a fast 8 way scrolling engine only using the attribute layer for the 48k. It scrolls at 4x left and right, an 8 vertical. I'm going to have 2 maps, one for each 4bit shift attribute. So all the ASM has to do is read the section of the map to the attribute screen and like magic it will ...

This is my attempt at what Sonic would look like using attribute writes on the 48k It would absolutely fly in this mode, I'm trying to do an ASM routine that writes this at the fastest speed I can, then I'll do a little scrolling demo. Please note, I know nothing about drawing graphics, will have to...

This is absolutely excellent, the way you've laid out the screen is perfect.

There are so many good arcade conversions now, I love to see them.

I figured it was doing that on the 128k, isn't that how the Super Mario game does it? I want to get as close as possible on the 48k. I'll probably limit the amount of platforms which can be visible on the screen, draw as little as possible using all the tricks I know. I'm trying a few interesting tr...

Completed. Wonderful game!!!! https://i.postimg.cc/RJCfBsp3/end.jpg Ohhh well done, PM me your address if you want the hoodie! There is a second ending if you beat my score on each level, it has a 'par' at the end of every level once you've completed it. Time to port it to the CPC I think, a machin...

Thanks everyone! I promise the game gets easier once you learn to react quickly, and it does keep your progress, there is no going back to level 1! I've said I'll give a free heated hoodie to anyone who completes all 5 levels, and the prize is still available! I've got major plans for this and want ...

Here is my frantic scrolling platformer. Originally it was just a Mario style game, but I found it a bit boring, a coding error meant I found a much more fun and frantic game where I accidentally made it so you could not stop. 5 levels of crazy scrolling jumping ahead of you. Any key is jump, the lo...