How to remove / erase saved game from Doki Doki Panic

Started by featherplucknfilms, March 24, 2007, 08:46:18 pm

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Xious

AFAIK, the only way to erase the save data is to rewrite the disk, which is a huge pain, due to the copy protection schema used on it.

Once I get my MGD1 working properly, I could re-write them for people...

-Xious

UglyJoe

Read the thread, dude, I explain how to erase the save game via corruption.

Xious

My post was sitting there and spinning its gears while this was still a one-page conversation, and apparently didn't go through until I ticked reload some time later...

Aside from the obvious potential issues with corrupting data on the disk, the problem with this is what when you hit reset, there is the possibility of a slight electrical surge that can cause bad blocks on the disk.

Ejecting the disk while writing is probably the worst idea, as the write head is still active and if it touches the surface area of the disk, it will blow away whatever is there. The game data is also on the same side as the save files, so this is possibly a way to convert your disk into a coaster, if done incorrectly, or repeatedly. Apparently, JC had some kind of problem in attempting to do this, but I have no idea how he tried to corrupt the save data.

Also, out of curiosity, does this erase all the save files, or just the one that you were using?

I think the plan with this game was to force kids to make repeated trips to the Disk Writer machine. Then again, I hardly expect that the programmers considered that twenty-three years later, people would still be playing this game.

-Xious


nintendodork

Well, since it corrupts the entire contents of the disk, I would assume it erases all the saved data on the disk.
I like to glitch old VHS tapes and turn them into visuals for live music events. Check out what I'm working on - www.instagram.com/tylerisneat

Xious

Isn't there game/level data on the same side of the disk as the save files? I could swear that the save side is A, which is also the side from which you need to initially load the game. If there is naught but save data on one side, it would be a snap to use a blank FDS disk to do this too.

I wonder what would happen if you insert any other disk into the drive when writing the save data. :)

As a side-note, if you only want to erase one or two of the save files, you can do this with a hex editor on an image file, then write it to a disk, or if you have disk management tools, you might be able to do it right from your Famicom by erasing the data file from the disk's directory structure.

I know one of the 'Disk Tools' disks can view and edit the data on a FDS disk this way.

Now I want to muck around with this to uncover how the save files work.... i wonder how hard it would be to add an /Erase Save File' option to the menu screen so that I could create an image file for people to use that has the erase feature added.

It may be possible to use some of the code from Zelda no Densetsu or Akumajou Dracula to do this if i disassemble the Yumi Koji DDP files and see how they tick. .  :-\

-Xious

UglyJoe

Quote from: nintendodork on August 04, 2010, 01:31:15 am
Well, since it corrupts the entire contents of the disk, I would assume it erases all the saved data on the disk.


It does not corrupt the entire contents of the disk.  All you're doing is writing only a part of the save file (instead of the whole save file) and this causes the save file to be corrupted.  When the game tries to load that save, it sees it's not a valid save file, and it erases or overwrites it.  So, only the portion of the disk that holds the save file is getting corrupted.

maverick

not knowledged on remove/erase saved game on doki doki. but...........

it all started when my original zelda went bad before i could dump it( had probs with fds-pc dump cable). thought i could save the image and i did. then dumped the rest of my games. the only one left staring at me was doki doki. knowing about the copy scheme i set out to conquor doki doki. i hooked up my laptop/fds-pc dump cable and dumped both side of doki doki. updated fds file and returned to windows. when i loaded up side a: all good. when it said "set side b" it came back with please use nintendo  bs).

discouraged, but focused. i set out to see the difference between my dump of doki doki and the 9, yes 9 dumps i found on the web. thats when i started noticing alot of them were very different from each other. i was looking for the differences between them when i should of been looking at what they had in common. and when i did that i struck gold! so i thought if i could export that file from one of the images and add it to mine, would it work? and yes it did and does!!  im not saying this is the best way to do this, yes you could use some copy program too and copy it too. but some people dont have a copy program and some people are "keeping there images to themselves" . so for some people who might not want to use some hacked up doki doki.fds image  to re-write there disk or cant find/get copy program, this might be an option on backing up there doki doki.

all i takes is dumping the game with fdsloadr and a little help with fdsexplorer. but it involves adding a file on side b(the same side the game looks for copy protection file). i have made a step by step instructions with file included ((including data and names to fill in), and they so simple anyone can do it. but i figure nobody would be interested in it because adding a file is quote not original data. but did you know that every doki doki panic.fds  image on the web has this file??? its true!!  if/when my doki doki goes bad, i didnt want to use the many images on the web.( most are changed alot) i wanted as close to the original as i could get. so adding one file to the 110% true data is better than some of the images that have been changed alot.(of course no offense). im not 100% on this, but i think when the game looks for the copy protection file it sees this file as "original disk". after you add the file you save as .fds file, and you can name it differently than your dump or the same as your dump. your choice. works in fds-ram cable/emulator. if anybody is interested let me know. in my opinion doki doki conquored!!!!!    ;D

Xious

The file you're talking about are hidden at the end of the disk by not including them in the file counter in the second lock of the disk. If this block doesn't specify the correct number of files, most copying tools stop reading after reaching the specified file count, so any data stored after them is lost.

What you are doing is manually restoring the files that you didn't read-in when you archived the original disk. The FDS images on the 'net aren't rigged in some way to avoid this problem, but whomever made them made sure to read to the end of the media before making the images.

Dome tools (Disk Hacker II and Disk Keeper v1.3, I think) do a full read f the entire surface of the disk, and others don't' The trick is knowing which tools to use for this kind if problem. FDSLoadr can as well, but you need to be sure to read until you find a large gap (all zeros), which is the true end of the disk.

-Xious

Profeta Yoshitake

Bump!

I'm truly amazed! My copy of Doki Doki came full of saves and I always wondered if there was some way to erase it. I'm gonna try UglyJoe's method sooner or later. But I'm not posting here because of Doki Doki. I don't know if this is the right place, but I have also a F1-Race disk that the former owner has done everything possible and I never could actually enjoy the game because of that. I wonder if any of you guys also had that problem. (I'm hoping someone responds that I'm a freaking noobie and there is a quick a easy way to erase the F1-Race data!  ;D)
Now Playing: Dragon Ball Fusions, Yggdra Union

P

Sadly corrupting the save file or rewriting the whole disk seems to be the only way to go with most FDS games. Here's another F1 Race thread: http://www.famicomworld.com/forum/index.php?topic=10383.0.

boye

Sorry for the necrobump, but here's UglyJoe's DDP save deletion method in video form.
https://youtu.be/5aiSt7RIfJI

P.S. Deleting DDP save data seems kinda like a mini-game, doesn't it?
Can't find the FDSLoadr PC program? Get it here. It took me way too long to find.