Atari 2600 motion blur research and experiments
Posted: 12 May 2018, 10:34
Motion blur on the Atari 2600?
This might seem like an impossible proposition, but I have written a soft blitter chip capable of outputting 30 and 60 FPS of full screen animation on the Atari 2600.
I also created a BASIC to harness the soft blitter, making it easy for anyone to do research and experiments with animation and motion blur reduction.
These experiments are possible because the Atari 2600 has a nonstandard video signal that is not interlaced, rather than putting out 60 fields per second it outputs 60 full frames (240p) on a classic tube Television.
Some Atari emulators like Javatari can reproduce this effect on the PC fairly well, though a classic console connected to a tube television is best for experiencing the full cumulative rendering effects of phosphor persistence and artifact colors also present in these experiments.
(Note that an LCD monitor connected to a classic Atari console may merge frames, improperly rendering the output as 240i instead of 240p which prevents viewing these experiments).
Experiments and examples:
STARBLITZ - a fast action Defender style game for the Atari 2600 where you save the cities of Mars from comets and meteors while fighting off aliens and surface to air missiles and catching score power-ups to advance to the next wave.
You can try this example in the browser with Javatari, an online Atari emulator:
http://javatari.org/?ROM=http://relatio ... le_fun.bin
Or you can download it to try on your classic console (you can also convert the binary to a WAV and load it via the SuperCharger if you have one):
http://relationalframework.com/StarBlitz_double_fun.bin
When the game loads you will see really fluid animation on the title screen, press the button to start a game and see the smoothly scrolling cityscape.
Now you can use the BW switch (it's in the lower left on Javatari) to switch between 30 and 60 HZ; the game stays at 30 FPS so at 60 HZ the frame is doubled creating a blurry effect with visual artifacts that exist only on your retina.
Because of the full screen animation the motion blur reduction is readily apparent and makes the game more fun to play, an old-school CRT Television maximises this effect further because of the phosphor persistence and artifact colors.
WARPDRIVE - This example has the opposite approach of doubling the frame rate to make it match the HZ to reduce motion blur but the game consequently becomes twice as fast:
Press the button to start the game, then you can use the BW switch to turn on the WARP engines, speeding up the action to 60 FPS and eliminating the motion blur, the effects are readily apparent.
http://javatari.org/?ROM=http://relatio ... VE_AFP.bin
http://javatari.org/?ROM=http://relatio ... VE_AFP.bin
Related experiment - reaction time on the edge of perception:
This game has the distinction of requiring a 30th of a second reaction time to beat at 30 FPS, and a 60th of a second reaction time at 60 FPS; people have mastered the game at 30 FPS but no one has beaten it at 60 FPS (let me know if you can!)
Here is another example of the game at 30 FPS with motion reduction via inserting a black frame:
http://javatari.org/?ROM=http://relatio ... LITZII.bin
KC Monster Maze - Ed Averett's classic KC Munchkin for the Oddyssey II ported as a panoramic scroller to the Atari!
This example uses a mixed mode video signal that changes dynamically from 60 HZ when the characters are animated at 60 FPS, to 30 HZ by inserting a black frame when the entire scene (background and the animated characters) is panned at 30 FPS by the camera:
http://javatari.org/?ROM=http://relatio ... aze_R2.bin
http://relationalframework.com/KC_Monster_Maze_R2.bin
Note that the game features cooperative play with the CPU - the AI takes over if you hesitate to turn, very different than what we are used to.
Hope researchers are ecouraged to experiment with motion blur reduction on the Atari 2600 and to create fun games!
Here is the program listing for the version of WARPDRIVE that inserts a black frame, it is only 9 lines of BASIC:
http://relationalframework.com/9LineBlitz.txt
And here is the program listing for STARBLITZ, this game uses the ASCII art graphics desingers to draw the sprites and the panoramic virtual world:
http://www.pouet.net/prod_nfo.php?which=66991
This might seem like an impossible proposition, but I have written a soft blitter chip capable of outputting 30 and 60 FPS of full screen animation on the Atari 2600.
I also created a BASIC to harness the soft blitter, making it easy for anyone to do research and experiments with animation and motion blur reduction.
These experiments are possible because the Atari 2600 has a nonstandard video signal that is not interlaced, rather than putting out 60 fields per second it outputs 60 full frames (240p) on a classic tube Television.
Some Atari emulators like Javatari can reproduce this effect on the PC fairly well, though a classic console connected to a tube television is best for experiencing the full cumulative rendering effects of phosphor persistence and artifact colors also present in these experiments.
(Note that an LCD monitor connected to a classic Atari console may merge frames, improperly rendering the output as 240i instead of 240p which prevents viewing these experiments).
Experiments and examples:
STARBLITZ - a fast action Defender style game for the Atari 2600 where you save the cities of Mars from comets and meteors while fighting off aliens and surface to air missiles and catching score power-ups to advance to the next wave.
You can try this example in the browser with Javatari, an online Atari emulator:
http://javatari.org/?ROM=http://relatio ... le_fun.bin
Or you can download it to try on your classic console (you can also convert the binary to a WAV and load it via the SuperCharger if you have one):
http://relationalframework.com/StarBlitz_double_fun.bin
When the game loads you will see really fluid animation on the title screen, press the button to start a game and see the smoothly scrolling cityscape.
Now you can use the BW switch (it's in the lower left on Javatari) to switch between 30 and 60 HZ; the game stays at 30 FPS so at 60 HZ the frame is doubled creating a blurry effect with visual artifacts that exist only on your retina.
Because of the full screen animation the motion blur reduction is readily apparent and makes the game more fun to play, an old-school CRT Television maximises this effect further because of the phosphor persistence and artifact colors.
WARPDRIVE - This example has the opposite approach of doubling the frame rate to make it match the HZ to reduce motion blur but the game consequently becomes twice as fast:
Press the button to start the game, then you can use the BW switch to turn on the WARP engines, speeding up the action to 60 FPS and eliminating the motion blur, the effects are readily apparent.
http://javatari.org/?ROM=http://relatio ... VE_AFP.bin
http://javatari.org/?ROM=http://relatio ... VE_AFP.bin
Related experiment - reaction time on the edge of perception:
This game has the distinction of requiring a 30th of a second reaction time to beat at 30 FPS, and a 60th of a second reaction time at 60 FPS; people have mastered the game at 30 FPS but no one has beaten it at 60 FPS (let me know if you can!)
Here is another example of the game at 30 FPS with motion reduction via inserting a black frame:
http://javatari.org/?ROM=http://relatio ... LITZII.bin
KC Monster Maze - Ed Averett's classic KC Munchkin for the Oddyssey II ported as a panoramic scroller to the Atari!
This example uses a mixed mode video signal that changes dynamically from 60 HZ when the characters are animated at 60 FPS, to 30 HZ by inserting a black frame when the entire scene (background and the animated characters) is panned at 30 FPS by the camera:
http://javatari.org/?ROM=http://relatio ... aze_R2.bin
http://relationalframework.com/KC_Monster_Maze_R2.bin
Note that the game features cooperative play with the CPU - the AI takes over if you hesitate to turn, very different than what we are used to.
Hope researchers are ecouraged to experiment with motion blur reduction on the Atari 2600 and to create fun games!
Here is the program listing for the version of WARPDRIVE that inserts a black frame, it is only 9 lines of BASIC:
http://relationalframework.com/9LineBlitz.txt
And here is the program listing for STARBLITZ, this game uses the ASCII art graphics desingers to draw the sprites and the panoramic virtual world:
http://www.pouet.net/prod_nfo.php?which=66991