Hacking Acekard Rewind Thread

[golden]

So everyone these days is talking about the exclusive features that each cart has and that's pretty much the selling point of each cart because they all have 100% compatibility now. So, my proposal to all the talented and amazing programmers like Normmatt, Smith, and anyone else I left out is that if we could make an exclusive feature for the AKRPG/2 that beats all other carts' features such as RTS and slo mo. My thought is, if it was possible to make a exclusive "Rewind" feature in the AKRPG similar to the rewind feature in nesDS. If you don't exactly know what I mean go ahead and try nesDS and press "L" when playing a game. It rewinds the game back as much as you want until you let go of the button that activates it. This feature would far surpass any other like slo mo because it would prevent you from dying. Just rewind back to the point before you died. It would eliminate all need for slo mo. You could rewind any point you needed to. Try again. Redo that move, undo a decision. Essentially go back in time in your game. The reason for this thread is to know Smith's, normmatt's, and any other programmers' opinion of how difficult, or impossible, the implementation of this method is and to see what other people think of this idea. Yay? Or Nay? Vote in the poll.

 

[golden]

Ya, good points. The main point of this thread is to see what Acekard programmers have to say about it rather than actually getting it done.

 

[Destructobot]

I think that essentially requires the emulator to save the game state every second or so, and keep as many of those states as it has memory for. Then when you press the rewind button it just runs through the states until you get to where you want to be.

AKAIO doesn't even have normal save states, so I'm guessing that it will take a while for it to get a rewind feature.

 

[Normmatt]

This would require constant save states as Destructobot said, on the nes its total memory isnt very large iirc about 50kb so theres plenty of room in memory to store about 40 or so of them, which could be taken every second. The nds memory is the same size as what we have available so we can't store them in memory and trying to write to 30 files every second would create an intolerable lag in games not to mention wear out your microsd card. It was a nice idea but realistically its not gonna happen on any flashcart.

 

[Minox]

Not going to happen. RTS by itself takes a couple of seconds to save one save state.

 

[dib]

Hmm..theoretically you could achieve this by only cataloging memory addresses+values that _change_ between two iterations, rather than taking a complete save state. The fact is that within every second there are only a finite+limited number of values that are actually modified compared to the total memory.

Some debuggers or even cheat finders have tools along these lines, but they're not working within the constraints of the DS' memory. Not sure what kind of overhead we're talking about for managing this, so it may still be unworkable.

 

[coolbho3000]

But that's where external memory comes in.

 

[Japhle]

But that's where external memory comes in.

Actually I was just coming here to mention something similar to that.

 

[Destructobot]

That would still cause a lot of lag (slot 2 memory is pretty slow compared to main memory), and DS save states are 5MB a piece, so a slot 2 RAM pack could hold at most 6 rewind points.

 

[golden]

Use of the AceKard RPG's USB port (or the DSX)

WTF?

Wrong thread Pharaoh? What does the USB port have to do with this topic?

 

[Destructobot]

Even if there was a magic peripheral that could move data to a large chunk of memory as fast as the DS can send it, I still think that moving the entire contents of the DS's RAM would take too long to be able to do this without major lag.