From what I've read it had something to do with power spikes that would occur from time to time and delete the battery-backed save when you just hit power off. It's not actually required to hit reset to save, it's more of a precaution. Later cartridges were supposedly protected against this.

This post seems to provide a good explanation for the problems :

http://forums.nesdev.com/viewtopic.php?
f=9&t=7730&hilit=reset+battery+save

Great Hierophant wrote:

This post seems to provide a good explanation for the problems :

http://forums.nesdev.com/viewtopic.php?
f=9&t=7730&hilit=reset+battery+save

http://forums.nesdev.com/viewtopic.php?f=9&t= … et+battery+save

There was a line break in your URL for some reason. 😀

Gemini000 wrote:

Lately I've been playing through my copy of Dragon Warrior II again on my NES, (amazingly, the battery backup still works after 22 years, and yes I've had it for THAT long), and this got me wondering: We all know that with an old NES, in order for save-game data to not get corrupted or lost, we have to hold reset while turning the power off.

My question is: Does anyone here happen to know the technical explanation for why this is necessary? As in, what holding reset down actually does electronically that keeps save data safe?

The answer is, as is so often the case in consumer tech, cost-saving.

Ninty could have implemented something to keep the system sane when power was lost, but that would have cost a few extra cents per unit.

Intriguing... :o

It may not've been a cost-saving measure so much as a, "Well, we thought we were just gonna bring the FDS over from Japan but it turned out batteries were better but we neglected to design the console to take battery backed-up RAM into consideration and if we make the change now we have to confuse consumers since many will have a console without this special protection feature and..."

...yeah, I'm not surprised that they never fixed this issue. It probably would've just made consumers upset to attempt to. So instead, just tell everyone to hold the reset button down. Simple, cheap, doesn't upset anyone. :D

...still, anyone want to tell me how my 22-year-old copy of Dragon Warrior 2 is STILL saving data perfectly fine on its original battery? ^_^;

Gemini000 wrote:

Intriguing... :o […]
Show full quote

Intriguing... 😮

It may not've been a cost-saving measure so much as a, "Well, we thought we were just gonna bring the FDS over from Japan but it turned out batteries were better but we neglected to design the console to take battery backed-up RAM into consideration and if we make the change now we have to confuse consumers since many will have a console without this special protection feature and..."

...yeah, I'm not surprised that they never fixed this issue. It probably would've just made consumers upset to attempt to. So instead, just tell everyone to hold the reset button down. Simple, cheap, doesn't upset anyone. 😁

...still, anyone want to tell me how my 22-year-old copy of Dragon Warrior 2 is STILL saving data perfectly fine on its original battery? 😅

I have lots of NES and SNES games with batteries and the only one that had a battery failure or lost saves if you did not hold reset and power was a Gold Legend of Zelda. That was a very early revision of the same board that DWII uses. According to the post I linked, later boards added more passive components to lessen the likelihood of erasure and maybe lengthen battery life (or it could be that battery technology or later improved or later S-RAM chips consumed less power).

So I would avoid gold Legend of Zelda or Zelda II carts, Ultima Exodus and Baseball Stars, as they use early revisions of the boards known to be particularly vulnerable.

Gemini000 wrote:

Lately I've been playing through my copy of Dragon Warrior II again on my NES, (amazingly, the battery backup still works after 22 years, and yes I've had it for THAT long), and this got me wondering: We all know that with an old NES, in order for save-game data to not get corrupted or lost, we have to hold reset while turning the power off.

My question is: Does anyone here happen to know the technical explanation for why this is necessary? As in, what holding reset down actually does electronically that keeps save data safe?

What?!

😒 I've done this to a megadrive because someone told me to do it as a kid, so I never questioned why...

Did Ninty actually tell people to hold the reset button? Or is that something people worked out separately?

Some Nintendo Official Dealers did tell buyers to have that precaution, just didn't explain why, and so people just did that to any cartridge... regardless of having battery or not.

The "hold reset button when powering off" was in the game manuals. Here's one example from Kirby's Adventure:

http://www.kirbysrainbowresort.net/games/adventure/09.jpg

The instructions were on the Zelda and Zelda II save screens, but when Nintendo released those games on the Zelda Collector's Disc for the Gamecube or Virtual Console, it removed the message, which would have no meaning for a user of those systems.

One of my two Zelda carts lacks the warning message. It's also not a five-screw cart, but I since learned that most Canadian-made carts, even the early ones, were three-screw carts, so I have a strange hybrid of the early Zelda program code with the newer cart design, which apparently never happened in the USA. ;)

But yeah, many early NES games with battery backup actually ask you when you save if you want to continue playing, and completely halt the game if you say no, telling you to hold reset before powering off. (Or in Dragon Warrior 2's case, the "REST" button because someone made a typo.)

That's interesting, I've never heard or seen of this until now. Good to know!

<3 VOGONS. 😀

I'm pretty sure Final Fantasy 1 also instructed you to do this. I always complied, but never knew why.