BBC Micro and Acorn Electron demo effects

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BBC Micro and Acorn Electron demo effects

Post by 0xC0DE » Fri Apr 19, 2019 6:41 pm

EDIT: Currently converting all demo effects to work on the BBC Micro and on the Electron. Post renamed to reflect this.

Trying to push my 6502 coding skills and the humble Acorn Electron to the limit :mrgreen:

https://www.youtube.com/watch?v=lT0qxnIz3JU

electroniq-screenshot-20190419-204219-544728.png
Last edited by 0xC0DE on Sat May 11, 2019 6:02 pm, edited 2 times in total.
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Re: Acorn Electron demo effects

Post by oss003 » Fri Apr 19, 2019 7:31 pm

Nice job, looks great ....

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Re: Acorn Electron demo effects

Post by Elk2019 » Fri Apr 19, 2019 7:32 pm

Simply mesmerising! =D> A cool demo of your 6502 skills. Who knows, this may kickstart a demo scene on the Electron. Despite its limitations, the Elk is still an amazing computer and I commend all fellow users who continue to push the boundary and the Elk to its limits!

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Re: Acorn Electron demo effects

Post by 0xC0DE » Fri Apr 19, 2019 8:49 pm

Thanks guys :D
This is MODE 5. Double chunky spaced pixels. Real time calculation. No colour palette tricks or pre rendered animation.
The raster can be varied in size to alter the frame rate.
Looking for different effects that are still fast enough.
Last edited by 0xC0DE on Fri Apr 19, 2019 8:51 pm, edited 1 time in total.
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Re: Acorn Electron demo effects

Post by tom_seddon » Fri Apr 19, 2019 9:58 pm

Who'd ever have thought the Electron had it in it!

Would the screen address granularity be good enough to create something like one of the effects here? - http://norecess.cpcscene.net/the-elders-scrollers.html

--Tom

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Re: Acorn Electron demo effects

Post by davidb » Fri Apr 19, 2019 11:32 pm

tom_seddon wrote:
Fri Apr 19, 2019 9:58 pm
Would the screen address granularity be good enough to create something like one of the effects here? - http://norecess.cpcscene.net/the-elders-scrollers.html
Yes. I found that technique quite inspirational and I've been thinking about doing something like that for a while. Possibly also throwing in some palette changes as well.

One of the things that stalled my efforts was making music. I spent some time trying to write music players and compose tunes, and those things took a lot of effort.

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 20, 2019 7:04 am

I remember seeing that demo technique for the first time and being blown away, thinking "this is impossible!"
And just like DavidB I have been toying with the idea of trying this on the Electron ever since. I like the challenge of squeezing every last drop out of my standard (!) Electron. Would be cool to see what others can do. Especially when it is work in progress. No music required DavidB 8) :lol:
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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 20, 2019 8:06 pm

OK, I just had to see if I could make this work on an Electron...

viewtopic.php?f=53&t=16971

Enjoy :mrgreen:
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Re: Acorn Electron demo effects

Post by davidb » Sat Apr 20, 2019 10:54 pm

0xC0DE wrote:
Sat Apr 20, 2019 7:04 am
I remember seeing that demo technique for the first time and being blown away, thinking "this is impossible!"
And just like DavidB I have been toying with the idea of trying this on the Electron ever since. I like the challenge of squeezing every last drop out of my standard (!) Electron. Would be cool to see what others can do. Especially when it is work in progress. No music required DavidB 8) :lol:
We can build on some of the tricks developed in the 1980s in games like Firetrack, Impact! and Sphere of Destiny to do things like vertical scrolling and palette switching. There were also some interesting articles in Electron User that showed how to do horizontal and vertical mode splits.

I combined scrolling and palette switching for a title screen: MODE 1 Scrolling and Palette Effects. I'd like to revisit that to do something like Sphere of Destiny's road, but with a sun/moon/city rising from the horizon.

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sun Apr 21, 2019 7:24 am

Your title screen is very impressive. That is exactly what I'm talking about! It's giving me an idea or two.
I've seen plenty vertical mode splits but never horizontal I think. Do you have an example?

I really like seeing active Electron coders =D>
There are not many left I guess.
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Re: Acorn Electron demo effects

Post by davidb » Sun Apr 21, 2019 9:07 am

0xC0DE wrote:
Sun Apr 21, 2019 7:24 am
Your title screen is very impressive. That is exactly what I'm talking about! It's giving me an idea or two.
Thanks! That's the idea. :)
0xC0DE wrote:
Sun Apr 21, 2019 7:24 am
I've seen plenty vertical mode splits but never horizontal I think. Do you have an example?
See pages 28 and 29 of Electron User #7.07 April 1990.

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Re: Acorn Electron demo effects

Post by simonm » Sun Apr 21, 2019 11:48 am

Very cool!

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Re: Acorn Electron demo effects

Post by 0xC0DE » Tue Apr 23, 2019 8:39 pm

Proof of concept on Acorn Electron.
MODE 1, 25 fps (also works @50fps), smoothly moving background (320x256), static masked sprite (32x32) in the foreground, colour cycling.

This is the NON-epileptic version (but can still cause motion sickness :mrgreen:):
plasma-no-color-cycling.ssd
(24.5 KiB) Downloaded 8 times

This is the version with eye-watering colour cycling. Do NOT watch if you have epileptic tendencies!
plasma.ssd
(24.5 KiB) Downloaded 13 times

You can also watch it right here: https://www.youtube.com/watch?v=E7CGErkhqho


masked-sprite.png
Last edited by 0xC0DE on Fri Apr 26, 2019 10:16 pm, edited 2 times in total.
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Re: Acorn Electron demo effects

Post by 0xC0DE » Fri Apr 26, 2019 9:58 pm

The classic colour cycling demo effect on an Acorn Electron. Screen MODE 1 again. Usually max 4 colors. Now very colourful because of rapid palette switching and dithering.

Watch the video: https://www.youtube.com/watch?v=J4LJaTtDYPM

colors.png

Edit: it also works on a real Electron but it is a bit fiddly to get it just right. I will share the version that works on my standard Electron and hope to find out if it works on others as well.
Last edited by 0xC0DE on Fri Apr 26, 2019 10:19 pm, edited 1 time in total.
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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 27, 2019 5:38 pm

0xC0DE wrote:
Fri Apr 26, 2019 9:58 pm
Edit: it also works on a real Electron but it is a bit fiddly to get it just right. I will share the version that works on my standard Electron and hope to find out if it works on others as well.
Here is the tape image of the version that works "out of the box" on my standard Electron (no expansions). It shows smooth colour cycling at medium speed, appearing to move towards the bottom of the screen.

colors.uef
(24.18 KiB) Downloaded 4 times


And this is the disk image:

colors.ssd
(21.5 KiB) Downloaded 13 times


Every Electron emulator I've tested yields a slightly different result and requires some tweaking.
To tweak the timing press CURSOR UP or CURSOR DOWN. Watch the topleft of the screen where a number appears according to the current setting. Press ESCAPE to hide this number again.

On my Electron I get good results at values 01, 0E, 0F, 36, 37, 38, 39, ...
I would really like to know which values work on your Electron 8)
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Re: Acorn Electron demo effects

Post by oss003 » Sat Apr 27, 2019 5:47 pm

Your Youtube links aren't working ......
Video not found

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 27, 2019 5:53 pm

Hi Kees, that's really strange. I have just tested every single YouTube link on this page and they seem to work fine; for me at least.
What happens if you go to my videos through my YouTube channel page?
https://www.youtube.com/channel/UCWZ3gg ... 1ZMdN9-Cow
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Re: Acorn Electron demo effects

Post by oss003 » Sat Apr 27, 2019 6:35 pm

0xC0DE wrote:
Sat Apr 27, 2019 5:53 pm
Hi Kees, that's really strange. I have just tested every single YouTube link on this page and they seem to work fine; for me at least.
What happens if you go to my videos through my YouTube channel page?
https://www.youtube.com/channel/UCWZ3gg ... 1ZMdN9-Cow
All the same result ... are the video's public?

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Re: Acorn Electron demo effects

Post by Pernod » Sat Apr 27, 2019 6:47 pm

oss003 wrote:
Sat Apr 27, 2019 6:35 pm
All the same result ... are the video's public?
They're all good in UK.
- Nigel

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 27, 2019 6:52 pm

oss003 wrote:
Sat Apr 27, 2019 6:35 pm
are the video's public?
Yes they definitely are. Are you currently in China, Kees? :mrgreen:

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Re: Acorn Electron demo effects

Post by kieranhj » Sat Apr 27, 2019 8:06 pm

These are all great BTW, fantastic work! Now if you can just get the Electron ULA to play a decent tune then you’ll have all the ingredients for a demo production. :)
Bitshifters Collective | Retro Code & Demos for BBC Micro & Acorn computers | https://bitshifters.github.io/

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 27, 2019 8:36 pm

Thank you!
kieranhj wrote:
Sat Apr 27, 2019 8:06 pm
if you can just get the Electron ULA to play a decent tune
Now there's a challenge! :shock:

Has anybody ever gotten a decent tune out of the Electron's speaker? :mrgreen:
(any particular game with an outstanding tune I should check out for example?)
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Re: Acorn Electron demo effects

Post by tricky » Sat Apr 27, 2019 8:40 pm

Nice work, would have replied earlier, but got sidetracked looking at old threads about changing the whole palette per scan line on the Electron.

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 27, 2019 8:51 pm

Thank you tricky. And be careful, that's how I got sucked into coding all these effects. CAN... NOT... STOP! :D :mrgreen:
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Re: Acorn Electron demo effects

Post by Pernod » Sat Apr 27, 2019 9:45 pm

Lots of lovely test cases for MAME =D>
- Nigel

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sat Apr 27, 2019 11:18 pm

Pernod wrote:
Sat Apr 27, 2019 9:45 pm
Lots of lovely test cases for MAME =D>
Can you confirm they are working on MAME? I haven't tested yet.
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Re: Acorn Electron demo effects

Post by Pernod » Sun Apr 28, 2019 1:38 am

0xC0DE wrote:
Sat Apr 27, 2019 11:18 pm
Can you confirm they are working on MAME? I haven't tested yet.
I wasn't expecting them to look great in MAME but they're not far off. The worst is the plasma with the static acorn, it jumps around a little.
- Nigel

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Re: Acorn Electron demo effects

Post by jms2 » Sun Apr 28, 2019 7:25 am


Every Electron emulator I've tested yields a slightly different result and requires some tweaking.
To tweak the timing press CURSOR UP or CURSOR DOWN. Watch the topleft of the screen where a number appears according to the current setting. Press ESCAPE to hide this number again.

On my Electron I get good results at values 01, 0E, 0F, 36, 37, 38, 39, ...
I would really like to know which values work on your Electron 8)
The colors demo works perfectly on my Electron without needing to change anything from the default settings. It is VERY impressive! 8)
The plasma demo suffers from the acorn having ghosting effects which move around the screen periodically. To be honest this is impressive too, even though not intentional!

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Re: Acorn Electron demo effects

Post by 0xC0DE » Sun Apr 28, 2019 10:01 pm

Real time ZX Spectrum-like loading (and saving) screen for the Acorn Electron anyone? 8)

tapeloader.png

Watch my Speccy loader while loading and saving a program on my actual Electron: https://www.youtube.com/watch?v=MhnN_tYFbBQ
(you may want to turn down the volume a little bit for this)

8-bit inception!! :mrgreen:
Last edited by 0xC0DE on Tue Apr 30, 2019 11:55 am, edited 1 time in total.
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Re: Acorn Electron demo effects

Post by 0xC0DE » Sun Apr 28, 2019 10:23 pm

jms2 wrote:
Sun Apr 28, 2019 7:25 am
The colors demo works perfectly on my Electron without needing to change anything from the default settings. It is VERY impressive! 8)
The plasma demo suffers from the acorn having ghosting effects which move around the screen periodically. To be honest this is impressive too, even though not intentional!
Thank you very much! I will look into the ghosting effect. Can't remember if I've tested that particular one on all available Electron emulators AND on a real Electron. Probably not!

@Pernod: I will be testing all of them in MAME as well. Thanks for reporting back to me.
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