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Another Twilighte's magic trick?

Posted: Sat Oct 19, 2019 12:25 pm
by Symoon
I just found this hires screen in Twilighte's stuff.
Load it in HIRES.

Now, how does he do that? Apparently, there is no code. Tricky use of flashing attributes? Puzzling!

Re: Another Twilighte's magic trick?

Posted: Sat Oct 19, 2019 1:50 pm
by iss
Yea, it's fascinating. Here are the 'magic' bytes:
SPLASH2.png
Though it's so simple, to invent and use the trick one should have a special Oric-way of thinking ... or be Twi. :(

Re: Another Twilighte's magic trick?

Posted: Sat Oct 19, 2019 2:28 pm
by Symoon
Well spotted, thanks!
I wasn't aware that the flashing attribute actually seems to invert certain values.

Re: Another Twilighte's magic trick?

Posted: Sat Oct 19, 2019 4:25 pm
by ibisum
This really is the essence of Twilighte -- he always seemed to know exactly what he was doing, and the results were extraordinary for the Oric.

Re: Another Twilighte's magic trick?

Posted: Sat Oct 19, 2019 4:54 pm
by mikeb
.... I'm not sure, but isn't this what is used to "animate" the MANIC <--> MINER jumping text in the loading phase? That's in text mode, using single blocks though.

Combination of inverse video bits and flashing attributes -- inverse video complements the colours, not swaps them fg for bg) which gives you more colours to play with, OR by carefully selecting colours and their complements, stuff can appear and disappear -- Manic Miner uses RED and CYAN.

@Symoon the flashing attribute doesn't invert the colours. It alternates between normal output (fg = fg, bg = bg) and (all bg colour).

Let's call "normal" PAPER: Cyan, INK: Red

In theory, you can only have fixed blocks of cyan (bg), or red (fg). That's all. But :-

You can have a flashing attribute, followed by a solid block of RED (ink), which will go RED,CYAN,RED,CYAN

And you can have a flashing attribute, followed by an INVERSE block of RED (ink), which will go CYAN,RED,CYAN,RED (the opposite phase).

I think that's how it went ;)

Re: Another Twilighte's magic trick?

Posted: Sun Oct 20, 2019 6:36 am
by coco.oric
Waaow, another trick from the king of Oric's hires.
Nice idea, to help us waiting for the loading of the tape

Re: Another Twilighte's magic trick?

Posted: Sun Oct 20, 2019 10:01 am
by Symoon
mikeb wrote:
Sat Oct 19, 2019 4:54 pm
.... I'm not sure, but isn't this what is used to "animate" the MANIC <--> MINER jumping text in the loading phase? That's in text mode, using single blocks though.
I just checked and you're right! And we just discussed that a few weeks ago. I'm getting old ;)

Thanks for the flashing explanation!