Go to bottom

ISO by JAC! [web] & Jakub Husak

>>> ISO by JAC! <<<

An 8k demo for the Atari 2600.
Created for Sillyventure 2011 in Gdansk.
V1.0-2011-11-10 (party version)

Code and graphics by JAC!, sound by Jakub Husak.

This is my second Atari 2600 demo and it was a tough journey.
Anybody who thinks retro coding is simple should give this machine a try.

I wanted to create a demo which is different from existing "typical VCS"
demos which tend to use full screen effects at low resolutions without
transitions but with HMOVE artifacts on the left side of the screen.
I wanted to establish the classical logo/playfield/credits screen
layout from the good old days of the cracktros and Amiga intros. 
Ironically, on VCS this is much harder than full screen effects :-)
I wanted to create smooth effects which appear to be in multicolor hires
resolution on a machine with 21 bits of screen RAM and 8+8+1+1+1 movable pixels.
I also wanted as many effects as possible in 8k with a fast pace and
proper transitions. The complete lack of interrupts makes the last
one especially hard and expensive in terms of RAM and ROM usage.

I'm fucking proud of the result and I hope you like it a bit, too.

ISO Logo
Isometric 3D logo in 92x84 multicolor hires pixels with time dependent shading and flexible height.

Floating and Falling Text Tiles
Text engine which draws arbitrary text in a virtual 160x60 pixels area (double scan lines).
Up to three parallel drawing threads running at 50 FPS.
Support for visual fading in, fork and join.
Text is transformed dynamically into falling tiles of 4x18 or 4x16 pixels.
Falling tiles are subject to gravity and bounce of the left/right screen boundary.
Falling tiles fade out while they approach the bottom of the screen.

Mirrored sin-sin double ribbon in 144x157 pixels resolution (single scan lines).
X-positions translated to full PAL palette (single scan lines).
Presented with 3 different speed and color variations at 50 FPS.

10x26 pixel, full 104 color plasma running at 50 FPS.
sin(x)+sin(y) movement translated to full PAL palette in three variations.

Shaded twister in 44x158 pixels resolution (double scan lines).
Variable X-positioning and black 8 pixel shade.
Presented with 3 different speed, color and movement variations at 50 FPS.

10x26 interleaved pixels mode for virtual 20x26 pixel resolution.
Full 104 colors twirl running at 50 FPS.
Rotator, circle zoom and spiral variations translated to full PAL palette.

Scrolling "Sillyventure" logo with 104 colors in 64x7 blocks at 50 FPS. 
Scrolling resolution 160x156 pixels, 3 pixel horizontal resolution
Black, flashing, cycling logo colors.
Flexible line height (single scan lines) and color bar background.

Thanks to:
- Grey/MSB for organizing Sillyventure and being so crazy as to start a VCS demo compo
  ... and for stretching the deadline
- Jakub Husak for the great tune
  ... and the player additions .. and keeping the deadline ... eventually :-)
- d-wilson for finding the article on "Why 2:16 minutes" again
  ... though the demo now takes 3:31 in the end. I had too many effecs :-)

Greetings an respect to:
Noice (cool ideas), Trilobit (cool stories), Tjoppen (cool execution)
and all people at Sillyventure - one day I'll be there, too.
Go to top