Colmino

I was very slightly, vaguely familiar with the fact that there was a game out there that did it, but I'd always assumed that either 1) the cartridge had some extra, necessary hardware for offloading the processing, or 2) it simply used up most of the available processing whenever the technique was utilized, making it only useful for non-gameplay scenarios (as seemingly corroborated by the example in your linked video). Learning that Draconian is actually doing this on an unenhanced VCS, during what is already vastly more advanced gameplay than in almost any commercial title ever developed, is frankly mind blowing. I thought I was used to the phenomenon of the VCS having insane unintended potential, but I was not braced for this. Forget what I said about extra voices—I can definitely appreciate the appeal of making the most of what literally existed in 1977.

Thank you for the detailed writeup. It turns out that my fundamental misunderstanding was that sprites can in fact be repositioned before moving to the next scanline, which I had assumed to be impossible, possibly due to the chosen methodology of the Space Invaders port, or perhaps I was conflating other data such as the limitations on playfield color. Edit: Incidentally, I've long considered Draconian to be among the top three most impressive things I've ever seen someone make the Atari 2600 do. Belated congratulations. The miracle of digital sound is something I've been meaning to investigate. If it's being helped along with an extra chip, perhaps someday you'll return to the title and go whole hog with that approach and give it all the voices it needs to replicate the arcade sound without compromise. That seems to be the popular choice with homebrew lately, especially with the advent of the AtariVox+.

Well this certainly completely changes how I'll be scrutinizing things from now on. (I'll have to check the .bin out later, but thanks.) Now I'm left wondering why the enemies in Galagon need to be so widely spaced, and whether it might have been possible to cause their spacing to expand/contract like it does in the arcade original (Galaga). The spacing in Galagon is so wide that they have almost no room to float left/right. I'd always assumed this was simply a limitation dictated by the needs of sprite tripling and whatever else was done to display the enemies.

I wasn't aware that this could be done during the actual drawing of the scanline. That begs the question of what the theoretical minimum time on this repositioning would happen to be.

I'm reading they are all single pixel in detail, any height (of course), and several different widths, albeit, again, only a single "pixel" in total detail. So I'm trying to figure out how games like the original Galaxian port, the homebrew Galagon, and the homebrew Space Instigators manage to display 7, 8, and 9 simultaneous horizontal sprites, respectively. You take the player sprites (8 pixels of horizontal detail) and triple them up, and that gets you a maximum of 6, like in the port of Space Invaders. Now, in the footage I've seen of Space Instigators, whenever a missile passes a line of aliens, it disappears outright, suggesting the obvious: That the missile sprites are serving duty as additional aliens. There is a strong disconnect between what I've read about player/missile/ball sprites and what is going on in these games. I seek a clarification.

Ah. Come to think of it, I don't think I ever saw UFOs back in the day when I played the game, so I guess I always picked that mode one way or another.

This feels like a casualty of limited ROM. Combined perhaps with a lack of engineering skill to pull off stuffing more features into said ROM. Similar to how the asteroids themselves only travel along certain vectors that are mostly vertical and slightly horizontal -- the result of an inability on the designer's part to envision a way of doing this better. Unlike the various Asteroids homebrews that came later. (Footnote: Asteroids was one of many games that served up an uncannily cheat-mode glitch if one undertook to "fry" their 2600 with it: It would result in a game mode where all asteroids came from the right side only, requiring the player to shoot in only one direction forever.)

I recall watching a different interview in which he recalled being sheepish over being called out on his unnecessary visual reinventions with Space Invaders. (This was leading up to where he was explaining why he left Atari after subsequently producing the, as you point out, far more accurate Missile Command.) I admit to being unconvinced about needing to seek help in creating graphics for enemies whose total resolution was 8x8. If he were concerned about it as much as that, then even a cursory consultation of the arcade original would easily have resulted in something much closer, even with the same resolution, as illustrated here. I am saying that legitimate artistic skill should be a non-factor at such limited and easily-accessible levels of detail. And indeed, the aliens he came up with were creative enough to make it all the more easy to dismiss this thought.

I thought about bringing up Pac-Man as a counterexample, but I figured everyone here would already be familiar with that effort's unique genesis. (In that it was basically a proof-of-concept which found itself being used as a final product by a hasty Atari.) But it would still be an interesting discussion. For example, we all know that the arcade Pac-Man played a two-voice jingle at the start of a new game. And we understand that the Atari 2600 Pac-Man was not originally intended to be what ended up on a cartridge. With those stipulations in place, it remains difficult to account for the very, very odd (unique in all of gaming) snippet of music that Tod Frye came up with. My headcanon explanation for its inexplicable quality is that Frye elected to reuse a short preexisting sequence of ROM, rather than attempt to hand-compose the actual tune or indeed any tune.

Speaking of Space Invaders... I've always wondered when folks would get together and have a chat about a video game phenomenon I've always wanted solid answers on. And that would be the phenomenon of home ports of video games (prior to, say, the mid-late 80s) seeming to go out of their way to be different from the arcade originals. I don't mean "different strictly because the limitations of hardware or ROM dictated it so", but different, like it was some kind of cultural philosophy or unwritten mandate that game engineers adhered to almost without knowing it. Space Invaders for the 2600 is a prime example. Along with the usual needless inaccuracies of sound effects and other minutiae, the graphics for the aliens and the base are needlessly huge deviations from the arcade graphics. It's pretty much exactly what you'd expect to get if somebody were deliberately making a bootleg knockoff of an arcade game and wanted to skirt around copyright, as opposed to having the license to produce a port fair and square. Space Invaders is a solid case-in-point, but this phenomenon is 100% reliable during this era. Engineers going way out of their way to re-make the visuals and sounds of their ports in some personal vision of theirs, when in the same amount of ROM they could painlessly have produced something much truer (and made buyers happier, leading to better sales). Growing up during this era and after, when ports of games started to appear which had taken obvious pains to mimic their arcade counterparts, it was always conspicuous and exciting, like I was seeing the dawn of a new era. And now that we have modern homebrew efforts to point to, this trend from the early 80s is exposed all the more. Why? I admit I tend to hope the answer is something more elaborate than the obvious, arbitrary guess that "they literally cared so little about accuracy that they were effectively working from either a vague familiarity or a one-paragraph description of the arcade original".

Heck yeah. I was going to suggest Draconian just because I'm interested in the digital samples. Mappy? Technically I understand how they did everything in that game. But that doesn't change the fact that it's the single most amazing thing ever created for the Atari 2600 by a factor of at least two. Literally the only two things I would change to make it even more perfect: 1: The sound of trampolines. Arcade used two higher-pitched tones slightly offset from one another; emulation uses single low tone. Since this is by far the most common sound effect in the game, it feels important that it be done justice. 2: A longer (arcade-accurate) delay after Mappy enters and before the game begins in earnest.

I just realized that there actually is a game that has my favorite sounds (not my favorite music, as with Journey Escape). Realized it because I've spent my whole life imitating the sounds in question. Mousetrap. The simulated cat meow, and the odd lower-register noise it makes when you change into a dog (presumably the best attempt at a dog bark). The meow is rather remarkable, even if it definitely sounds like typical 2600.

Every game? A few games with single-voice music that I can recall: Sneak 'n Peek: https://www.youtube.com/watch?v=WZsCDIfyh6A&t=0m5s A potentially fun game as long as you actually have two people. Reactor: https://www.youtube.com/watch?v=9tn2hXDc5ZY&t=0m5s Also fun. Genuinely good arcade action. But mostly I remembered the music. I even recreated it on the Apple II at some point. Venture: https://www.youtube.com/watch?v=fvmEhlAJGww&t=0m2s The arcade version of Venture - a very rare beast that I only saw fully functional once - left a permanent impression on me, it being the first game I ever experienced that had a robust soundtrack. The hallway music was particularly enchanting because it was such an unusual chord progression. When the game became available on the 2600, I was already braced for a downgrade, but the great hallway music was reduced to a repeating two-tone "tune" lasting 0.5 seconds in total. Still, there is something hypnotic about it. Speaking of the arcade version of Venture, incidentally, the opening theme (upon starting the game) never gets to play in its entirety, as it is quickly interrupted by the hallway music. Some time ago, I undertook to isolate the opening tune and permit it to play in full. This makes me the only person on the planet besides the composer ever to have heard the full tune.

If we're going to cite every 2600 game that used both voices (or more) for music, I may as well mention Strawberry Shortcake. https://www.youtube.com/watch?v=SYfPPlfJOZ8&t=0m31s I somehow owned this cart, and yes I did pop it in once in a while - a fact which underscores the boredom only made possible by the non-existence of the internet.

Sound on the Atari 2600. This is actually one of my favorite things to think about. The inherent limitations - primarily meaning the fact that there are only two voices, but also the fact that the scaling of pokable values doesn't match well with 12-tone polyphony, especially at higher registers - meant that only a very small number of games bothered to employ music, and especially not during gameplay. (Pitfall II is a unique exception as its internal guts afforded a grand total of four voices.) This gave Atari games a reliable patina of stark impersonality. It's the console of bleeps and bloops and mechanical indifference, and often just utter silence - a phenomenon naturally helped along by its graphical limitations. Not a criticism; I personally relish that about the 2600. As for my favorite "sound", my answer has to be Journey Escape. The game has music playing almost 100% of the time, only taking short breaks for the (also musical) sound of colliding with an enemy. The main BGM increases in intensity the longer you progress without getting tagged. And even though the tune is very short and repetitive, I very much like it. It doesn't hurt that the game is also one of the few solidly playable games out there that can be legitimately beaten, and without excessive frustration or ease.