Can any emulator switch games without restarting?

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Can any emulator switch games without restarting?
by on (#112285)
Hi I watch a video about SMB tricks that require changing game without switching off the hardware.

http://www.gametrailers.com/full-episod ... ost-levels

Can any emulator do this? Does this require lots of work to implement?
Re: Can any emulator switch games without restarting?
by on (#112286)
Well, any emulator with a debugger will let you poke the values into RAM that you need to trigger the kinds of things these tricks do. It'd be easier to pull off than cart-swap tricks.

However, if you do want to do this, I think you could just run Tennis up to a point, make savestate, and then open SMB and load that savestate over SMB? If the savestate format turns out to be directly bound to a particular ROM, you could use a hex editor to translate just the RAM portion, maybe.
Re: Can any emulator switch games without restarting?
by on (#112297)
You could do the same thing with bankswitching if you hacked the two roms together.
Re: Can any emulator switch games without restarting?
by on (#112300)
That could be done with #66 or (GNROM) or #11 (Color Dreams) or #201 (32K PRG and 8K CHR switch with the same bank number). But the emulator would need to have a debugger to let the user issue a bankswitch before soft reset. A reset-driven multicart mapper would be ideal, but #60 has 16K banks, and SMB1 is too big.
Re: Can any emulator switch games without restarting?
by on (#112311)
Very interesting suggestions, thank you.
Re: Can any emulator switch games without restarting?
by on (#112318)
If you want to do that just change the world number in SMB in FCEUX's hex editor.

Also, shame on them saying the 10NES's reset will be a problem it cart swapping....it doesn't clear the RAM! :)
Re: Can any emulator switch games without restarting?
by on (#112324)
3gengames wrote:
Also, shame on them saying the 10NES's reset will be a problem it cart swapping....it doesn't clear the RAM! :)


But you have to hit reset for the cic to lock with the new cart. Which in turn the new cart WILL clear RAM. That and even if you didn't have to hit reset, the cic is resetting the cpu which still points it to the reset vectors on the new cart, still clearing ram. So technically they are correct.
Re: Can any emulator switch games without restarting?
by on (#112325)
But they state clearly at the very end of the video that if you wish to do this trick, you either need a top-loader NES (lacks CIC) or a modded slot-loading NES (w/ CIC disabled/shorted out).

The most enjoyment I got out of the video was 1) hearing about those gaming mags in Japan, and 2) seeing Tepples mentioned.
Re: Can any emulator switch games without restarting?
by on (#112327)
infiniteneslives wrote:
But you have to hit reset for the cic to lock with the new cart. Which in turn the new cart WILL clear RAM.

The whole point of the video is that the games read part of RAM before clearing it to distinguish a reset from a power cycle. If pressing reset cleared RAM, then there would be no difference between a reset and a power cycle.
Re: Can any emulator switch games without restarting?
by on (#112328)
tepples wrote:
infiniteneslives wrote:
But you have to hit reset for the cic to lock with the new cart. Which in turn the new cart WILL clear RAM.

The whole point of the video is that the games read part of RAM before clearing it to distinguish a reset from a power cycle. If pressing reset cleared RAM, then there would be no difference between a reset and a power cycle.


Ahh you're right. I couldn't view the vid at the time and was relying on old degraded recollection seeing it/similar awhile back...
Re: Can any emulator switch games without restarting?
by on (#112338)
Without being able to reset you wouldn't be able to recover from the crash you'll inevitably get when you pull the cart out.
Re: Can any emulator switch games without restarting?
by on (#112352)
Ahhh, so the best way to do this is hold reset before removing and while inserting SMB, so that the CPU can't crash and corrupt RAM at all. So why would you even need the CIC disabled?
Re: Can any emulator switch games without restarting?
by on (#112353)
Upon further review and consideration I wouldn't imagine you do. :)
Re: Can any emulator switch games without restarting?
by on (#112361)
One big difference is that I guess SMB/Duck Hunt multicarts may be more common than SMB alone here.