I don't know about the run shown in the OP, but there are a fair number of memory-manipulation/ACE speedruns that are feasible in RTA ("real-time attack", a.k.a. something a human could pull off, as distinct from TAS). Off the top of my head I can think of such routes for Pokemon Red/Blue, Ocarina of Time, and Super Mario World.
To answer your question of "how likely is one to pull this off" for those three, the Pokemon one requires no almost advanced execution, other than turning off the console at a precise point to corrupt the save data you otherwise just need to follow a simple (though long) series of steps. The Mario one requires some pixel-perfect precision, and runners often used hacked ROMs that display coordinates in order to train. The Zelda one requires exact angles to be held on the analog stick, and I've heard of people creating guides out of cardboard and rubber bands in order to help them achieve the angles more reliably.
Sorry that I don't have any video links on hand, but you could almost certainly find examples of these in the GDQ archives.
EDIT: Found a good video for the SMW example, by SethBling, which actually goes a step further and manually reprograms SMW into Flappy Bird: https://www.youtube.com/watch?v=hB6eY73sLV0
Even then, some of the timing accuracy required still mystifies me. E.g., if I got it right then, for the RNG manipulation to work, you have to press "A" on the menu screen in one particular frame, counted from when the console was switched on. At the standard PAL framerate of 50 FPS, this gives you 1/50th of a second to react, with no visual indicator that the frame you're looking for is about to come up. I have no idea how to even begin training this.
There are some cues you could use to get very close, particularly the rhythm of the music.
I've heard that a decent drummer can hit a note within 15 milliseconds of the mathematically correct point on average, and that makes it plausible that you could use rhythm as a cue to hit within the 20 milliseconds that this would require.
But obviously this would become less likely to succeed as the length of the game continues and timing errors that affect the soundtrack compound.
Fighting game players regularly hit 1/60th of a second frame links.
For example, Guilty Gear XX's "one frame jump" is required to escape some pressure strings. This requires one-frame precision (1/60th of a second), pushing "Barrier" on frame 3.
If you push Barrier on frame 1 or 2, you're grounded and won't jump. If you push Barrier on Frame 4, it doesn't make a difference (because your character's animation is the same by frame 4). Its literally a 1-frame button timing.
Street Fighter IV had a fair number of 1-frame combos as the bread-and-butter for many characters. These 1/60th of a second links may be character specific (since all enemy hitboxes change based off of their relative sizes). They're also position dependent, because wall-bounce vs corner combos are a thing in most fighting games.
Most people, with enough practice, can execute this. Just most people don't realize that they can. This isn't even elite musician level.
Now what the expert fighting game player can do, is do the 1-frame link reliably during a tournament while the crowd is yelling and overall in a distracted environment.
> I've heard that a decent drummer can hit a note within 15 milliseconds
I find that easily believable. I think human reactions can be very fast and very precise if there is some kind of feedback - e.g. a clue, pattern or rythm to latch onto.
What I find harder to imagine is precision without any feedback - e.g. a human player pressing a button after exactly 15 milliseconds, without any kind of clock.
...but as you say, there may actually be some clues.
The NES, and many other early computer/game systems, don't bother sending an interlaced display. Basically, they omit the half scan line at the end of one frame that positions the next frame lines in between the prior frame.
That's what 288p is.
And the result is half the vertical resolution but at full frame rate. 50fps
Pal, intended for viewing movies, television broadcast does output that half scan line for the full vertical resolution, and the result is a full frame is seen every other frame.
That's what 576i is.
Twice the vertical resolution, half the frame rate or 25fps.
Ok, so standard PAL is 25FPS, but half vertical resolution PAL is “50FPS”. Thanks for the detailed explanation of why you call it 50FPS (as seen from game’s perspective, not the PAL spec as GP implied).
> And the result is half the vertical resolution but at full frame rate
This is incorrect. It would be correct if you said “full field rate” here. The PAL standard is 50 fields per second. Two fields comprise one frame.
Now as to the NES specifically, this link breaks down more precisely the game’s FPS (tl;dr, it’s neither PAL or NTSC’s frame or field rate exactly):
You should consider editing the downvote comment away. Wasn't from me, and my advice is to just ignore all that. I do.
Yes, that article is right about the timings. The signal standards were abused in small ways to improve graphic quality, get speed and more.
Similar things happen in NTSC land too. Those deliver 60 fps. Many TV sets will permit further abuse and deliver NTSC with more PAL like timings to get 50fps, but still with NTSC color encoding.
An Amiga and Color Computer 3 can both do this. It is correct to do in some parts of the world too. I have done it in video signal projects.
Whether my comment is incorrect depends on POV.
From the NES pov, and how gaming generally thinks of frames, its fine.
From the signaling POV field is more descriptive.
Consider when there is no interlace, what happens to the concept of a field? There aren't any. Just frames, as in one complete image completely displayed.
Many people think in simple frames per second terms. This is why many, particularly those who grew up during retro times, will say PAL 50fps. To them, PAL does in fact deliver 50 complete frames per second.
Edit, oh yes! I do see where I should have said field early on. Too late to edit now. Basically, when the half scanline is not part of the signal output, fields go away.
When it is, there are fields and they get displayed sequentially, interlaced fashion, one full frame displayed every two fields.
> This is why many, particularly those who grew up during retro times, will say PAL 50fps. To them, PAL does in fact deliver 50 complete frames per second.
That doesn’t make it correct, but I agree now in retrospect and thus edited my post.
(Also, agree re: intro part to your reply. The problem I have is when factually correct comments without anything wrong about them get greyed out)
Ignore it. Over time you get thicker skin, handle exchanges better[1], as I did here, and your net upvotes go up
Yes, not worrying about it improves it. Strange world sometimes, isn't it?
[1]not saying you are bad. No judgment here. And that's the point. I basically don't do judgment and treat you the same way whether I see upvotes or not. That really improves things.
BTW, some contributors to that forum thread are incorrect about interlace being about the number of scanlines.
Interlace requires there be one half scanline.
Whether there are an odd or even number of scanlines can impact color phase shifting, depending on whether the source signal is phase shifting the color burst.
Older machines, such as the 8 bit Apple 2, did not phase shift at all so color artifacting would be predictable and useful. Even vs odd scan lines would affect precise frames per second only.
GTA Vice City and San Andreas Any% are also memory manipulation. World record for Vice City is 8.5 minutes and 15 minutes for San Andreas. I think both are very precise but very much doable by speedrunners, although not consistently.
One of the Castlevania games (maybe Symphony of Darkness?) achieves ACE by inventory manipulation.
Mega Man 1 has an ACE category as well which is really interesting. I think Nudua explained it somewhere. (On my phone, but a quick googling should help you.)
To answer your question of "how likely is one to pull this off" for those three, the Pokemon one requires no almost advanced execution, other than turning off the console at a precise point to corrupt the save data you otherwise just need to follow a simple (though long) series of steps. The Mario one requires some pixel-perfect precision, and runners often used hacked ROMs that display coordinates in order to train. The Zelda one requires exact angles to be held on the analog stick, and I've heard of people creating guides out of cardboard and rubber bands in order to help them achieve the angles more reliably.
Sorry that I don't have any video links on hand, but you could almost certainly find examples of these in the GDQ archives.
EDIT: Found a good video for the SMW example, by SethBling, which actually goes a step further and manually reprograms SMW into Flappy Bird: https://www.youtube.com/watch?v=hB6eY73sLV0
EDIT 2: Here's an excellent explanation of the Zelda ACE: https://www.youtube.com/watch?v=wdRJWDKb5Bo