The gigascreen thread!

[DenisGrachev]

So, until the Super Mario Brothers thread, I'd not before heard of gigascreen. Or if I had, I'd forgotten about it. I'm gobsmacked by how good it looks on my ZXDS.

What other gigascreen games/demos do I need to download TODAY?!

Maybe it's time to heard about MultiGigaScreen - it's a combination of multicolor and gigascreen, or even about interlaced multigigascreen as a most powerfull speccy mode?

Btw, my game Twinglight https://spectrumcomputing.co.uk/index.p ... 6&id=31994 use a sort of uninterlaced multigigascreen, a combination of multicolor 8x4 and gigascreen to produce more colors.

There is a several problems with that tech and modern tvs. Gigascreen was widely use in exUSSR demoscene in 90-s just because most coders have a monitors\tvs that displays it with a very small flicker. That's why we still have a pure gigacreen flicked demos like:

https://youtu.be/OVLR4fGM2n8

At modern lcd tvs we have another problem when gigacreen works speccy switches in "LCD MODE" that doubles vertical resolution, so you gigscreen will be displayed not correctly and interlaced gigacreen too. So, that's why i prefer a ZX Evolution that supports even a English classic speccys timing but have a proper VGA scandabler that show a proper picture on LCD monitors even with gigascreen and interlaced one.

[moroz1999]

Some images from ZX-Art:

Gigascreen:
https://zxart.ee/eng/graphics/database/ ... e:flicker/
https://zxart.ee/eng/graphics/database/ ... e:flicker/

Gigascreen with multicolor 8*4:
https://zxart.ee/eng/graphics/database/ ... e:flicker/

Gigascreen with multicolor 8*2:
https://zxart.ee/eng/graphics/database/ ... e:flicker/

Gigascreen with multicolor 8*1:
https://zxart.ee/eng/graphics/database/ ... e:flicker/

[4thRock]

At modern lcd tvs we have another problem when gigacreen works speccy switches in "LCD MODE" that doubles vertical resolution, so you gigscreen will be displayed not correctly and interlaced gigacreen too.

Since 288p50 (Spectrum output) is not a standard SD resolution, the TV defaults to the closest valid mode: 576i50
Just like the Amiga interlace modes, this is like running the Spectrum with twice the vertical lines (256x384 active area).
In theory, if you used this effect with the Timex modes, you could get 512x384 with 4 colours...

(I'm no coder, but the Timex changed screen modes by sending data to the border address (OUT 255,62). Perhaps programmers could agree on similar signaling for other modes, that would tell emulators and real hardware what mode to display).

[stupidget]

This is what I get:

[media]https://youtu.be/7f4p45htPGc[/media]

[Ast A. Moore]

This is what I get:

Playing Spectrum games at a 16:9 ratio?

[stupidget]

Don't fret, I still get the same non-gigascreen image when I use 4:3

[Ersh]

Do you know any details about such a hardware mod? I've heard many rumours about this but I can't find any actual examples of mods that can do frame blending.

Nah, I've only seen it mentioned around the web, never come across any instructions or more detail.

This is what I get:

Yeah, that's clearly not working like it's supposed to. Must have something to do with how the LCD translates the output then (like DenisGrachev and 4thRock mentioned).

[Alone Coder]

The original Gigascreen schematics switched screens every other line. It was supported in Homer Simpson in Russia, then the port changed, later it was used in IzhNews and it seems, nowhere else. Mescaline doesn't use the device, it leans on emulator's "noflic" option.
There was a demo that used Mescaline-like multicolor effects with SOFTWARE gigascreen (i.e. switching lines by software) - Stellar Contour. Without flickering, there also were Eye Ache 2 and Anamnesis.
"Multigigascreen" technique (initially called MCX) was used in Hexagonal Filler game, but it doesn't switch every other line.


NB: the game is for is Pentagon/Scorpion/ATM/Profi/KAY, and the palette is based on Pentagon bright levels. This is what you see with "noflic" in emulator.

[Lethargeek]

There was a demo that used Mescaline-like multicolor effects with SOFTWARE gigascreen (i.e. switching lines by software) - Stellar Contour. Without flickering, there also were Eye Ache 2 and Anamnesis.

Kpacku is a better example - http://www.pouet.net/prod.php?which=66295

[4thRock]

Posting this here because it's related to interlace/gigascreen.

Take a look at this screen:

https://zxart.ee/eng/authors/p/pixelrat/rubi/

It uses "Timex TC2144/TC2128 Hi-Res Gigascreen", basically alternating between two monochrome 512x192 screens