Author Topic: - My First Safety Overscan Picture -  (Read 8923 times)

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Offline SuTeKH/Epyteor

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Re: - My First Safety Overscan Picture -
« Reply #50 on: 10:47, 23 August 11 »
Do you want that it will be scrolled like that:
That's a good place for me to start, yes.
Is that a 1 pixel scroll or 8 pixel scroll? I can't quite make it out from the video.
 

However your pic has 320*600, so you can make three pictures out of them and just scroll them. The above example uses four screens (64 KB V-RAM).
Can you explain how this is done? (Nothing over-technical, just the basics)
And I take it this was done on a stock CPC-6128 using upper RAM? That's the bit I can't seem to find too much info on, or maybe I'm just looking in the wrong places.
 

Offline rexbeng

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Re: - My First Safety Overscan Picture -
« Reply #51 on: 13:53, 23 August 11 »
Well, one thing I can say for sure, when seeing the C64 screen out of Edge of Disgrace demo: on the old CPC palette, it would look 100000 times better already. So, why bother in trying to emulate the ugly C64 colours in the first place?


And anyway, I think the real deal for a pixel-artist would be to use the normal CPC to produce images. Obviously the palette is limited, but there are so many techniques to mix pixels and colours so as tou give the impression that there's a lot more on the screen (have a look at Sylvestre's page, he has been the one working the most on such techniques http://sylvestre.cpcscene.com/).


Strictly from a pixel-artist's view (let's say that, at least, I don't think I'm the only one with that opinion :P ), there's no real challenge in using the CPC+ palette.


rb

Offline SuTeKH/Epyteor

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Re: - My First Safety Overscan Picture -
« Reply #52 on: 15:28, 23 August 11 »
@rexbeng 
You're right! The picture itself looks bad, even on a C64, due to the predictably dreadful colour scheme. But this is how I learn new things; I find something that already works and then try (usually with a LOT of help) to replicate it. I can read web-sites and documents and source code listings until the proverbial cows come home, but none of it will sink in; only when I've applied them to something will it make some sense.
 
From all of this I aim to learn (albeit at a infantile level); CPC+ HW 1-pixel vertical scrolling, ASIC/CPC+ palette, and CPC6128 memory manipulation.

Offline Carnivius

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Re: - My First Safety Overscan Picture -
« Reply #53 on: 15:38, 23 August 11 »
Well, one thing I can say for sure, when seeing the C64 screen out of Edge of Disgrace demo: on the old CPC palette, it would look 100000 times better already. So, why bother in trying to emulate the ugly C64 colours in the first place?


And anyway, I think the real deal for a pixel-artist would be to use the normal CPC to produce images. Obviously the palette is limited, but there are so many techniques to mix pixels and colours so as tou give the impression that there's a lot more on the screen (have a look at Sylvestre's page, he has been the one working the most on such techniques http://sylvestre.cpcscene.com/).


Strictly from a pixel-artist's view (let's say that, at least, I don't think I'm the only one with that opinion :P ), there's no real challenge in using the CPC+ palette.


rb

I agree with a lot of that too. Often said how, when doing Amstrad CPC specific stuff, I prefer using the original 27 color palette to the Plus' 4096.
Favorite CPC games: SwitchBlade, Stryker in the Crypts of Trogan, Turrican II, UN Squadron, Oh Mummy

Offline Gryzor

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Re: - My First Safety Overscan Picture -
« Reply #54 on: 21:05, 23 August 11 »
Still, I think that the Plus palette has just not been used to the full extend like the original hardware has. Imagine if someone taking the original hardware to the extreme took the Plus hardware to its own: wow.

Offline TFM

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Re: - My First Safety Overscan Picture -
« Reply #55 on: 22:21, 23 August 11 »
That's a good place for me to start, yes.
Is that a 1 pixel scroll or 8 pixel scroll? I can't quite make it out from the video.
 Can you explain how this is done? (Nothing over-technical, just the basics)
And I take it this was done on a stock CPC-6128 using upper RAM? That's the bit I can't seem to find too much info on, or maybe I'm just looking in the wrong places.

It's a 8 pixel scroll, to make it quick.
 
In your case you can load the three pictures to &C000, &0000 and &4000. So be setting the overscan bit of CRTC register (&0C ? like I've in mind: &F0 instead of &30). But be carefull if you use the block beginning at &0000, then you have to switch the interrupts off, save a part of the OS (&0000 - &0100) and restaurate it after showing the pictures. It will even run on a 464 stock CPC.
Get some information about the CPC CRTC at the inofficial amstrad ressource:
http://www.cpctech.org.uk/
 
...have a look at Sylvestre's page, he has been the one working the most on such techniques http://sylvestre.cpcscene.com/

Well, there is only french lyrics, no pictures...
« Last Edit: 22:25, 23 August 11 by TFM/FS »
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