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Old 10-03-2011, 04:53 AM   #1
Ohne Mitleid
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Default Floppy drive emulation for save games?

I'm trying to clean out all of the games on my drive that don't/didn't work. I have a copy of Stephen King's interactive fiction game "The Mist" from 1984. I couldn't remember why it was in my 'Deletion Decision' folder until I started to play. The game is timed by number of moves, and frequent deaths occur which necessitates saving the game. Problem? I could not figure out how to save. The option to save is there, but it seems I need to have the actual disks (I assume 5.25" floppies) to swap out so the game would register a saved file. One disk was to be for the Game, which I could easily DosBox play from my hard drive. The other was a Storage disk needed for game saves/loads. I finally got it to work, but I don't know why it does.

The game was mounted with 'mount c c:\oldgames\mist'. After many combinations of trying to get the game to save, the closest I could get was to have the game offer to initialize the save disk. This would return a ERROR - DISK IS WRITE PROTECTED, which also couldn't be circumvented. As a final effort, I created an image of a blank 180k floppy and mounted it as 'imgmount d c:\oldgames\mist\storage.img -t floppy'. When I was asked to initialize the disk as before, the game directed me to save the game in my choice of 1-9 slots, and everything was fine.

After saving, the directory listing reflects a file named SAVE, consisting of 0 bytes which contain no data, and a file named SAVEX, where 'X' equals the number slot chosen for the save game. From this point forward, you are able to save and restore without the need of the virtual drive... understood.

The name of the image file or different drive letters associated with mounting anything make no difference. These are the unanswered questions I have:
- The SAVE files are not written to the virtual img file or the imgmount drive, only to the root drive (c, in this case). Why?
- Is the creation of the SAVE file and recognizing that an alternate disk exists based on the application finding something in the directory listing? I don't understand.
If anyone has any answers, please feel free to post. I just got lucky but would like to know why it worked, if possible.
Thank you!
Ohne

Last edited by Ohne Mitleid; 10-03-2011 at 04:54 AM. Reason: Spelling correction
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Old 11-03-2011, 02:15 PM   #2
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you can also use regular directory mount command with -t floppy parameter. it will mount a part of your actual hard drive as a floppy drive, where you can then copy whatever you want to have on the virtual floppy

that way the files probably will stay saved in the directory..

another option is to use something like this. i actually use it often with dosbox, as dosbox natively doesn't support mounting of multiple floppy images at the same time (because of dosraider :P) and some games need to swap various floppies during the game's runtime
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Old 28-03-2011, 12:22 PM   #3
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Quote:
Originally Posted by _r.u.s.s. View Post
you can also use regular directory mount command with -t floppy parameter. it will mount a part of your actual hard drive as a floppy drive, where you can then copy whatever you want to have on the virtual floppy

that way the files probably will stay saved in the directory..
This doesn't seem to work or I don't have the guts/time/knowledge to follow through on things. The -t floppy part works, I assume, but the game itself is looking for a blank disk or a disk already formatted specifically for a game related save disk. Sure, I can set up the -t floppy parameter with DosBox, but when it comes to initializing the disk within the game, it gives me the **disk is write protected** error. Setting parameters for the virtual floppy with attrib does nothing.
Quote:
Originally Posted by _r.u.s.s. View Post
another option is to use something like this. i actually use it often with dosbox, as dosbox natively doesn't support mounting of multiple floppy images at the same time (because of dosraider :P) and some games need to swap various floppies during the game's runtime
Disappointing... I was looking forward to using this, if not now, in the future. Thank you for the link but since I am running Win7 (assumption), I get an error stating the application cannot run in Win 95/98/ME. Daemon Tools works adequately for this purpose though, so I am not out of luck.

Thanks for the response. I was more curious and looking for a possible explanation than anything else. This is just another oddity I ran into that I probably will not have to deal with again.
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Old 28-03-2011, 11:54 PM   #4
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If it's all about Mist, here ya go, I created a working combined playdisk/savedisk image from my game:
mist.img - 1.41MB
Mount the image as A:\ in dosbox,
imgmount a x:\path\mist.img -t floppy
Launch game from A prompt with game
you will be able to save the game (9 slots)
Saving is done with ingame save command.
Loading a saved game can be done when launching the game.

As for your questions
Quote:
Originally Posted by Ohne Mitleid View Post
The name of the image file or different drive letters associated with mounting anything make no difference. These are the unanswered questions I have:
- The SAVE files are not written to the virtual img file or the imgmount drive, only to the root drive (c, in this case). Why?
- Is the creation of the SAVE file and recognizing that an alternate disk exists based on the application finding something in the directory listing? I don't understand.
If anyone has any answers, please feel free to post. I just got lucky but would like to know why it worked, if possible.
Thank you!
Ohne
The game is meant to run from floppy drive, in those times the compy was also booted from floppy, remember(or not)?
You needed two disks, both with the OS files on it (command.com etcetera had to be in the root of the floppy), OS files on both disks were obligatory the same, you couldn't have dos 3 on one and dos 5 on the other, so to speak, et blah blah blah some more tech blah blah, bottom line:
saves were always done on A: (or eventually B: if you had two flopdrives)
If I read swell you mounted the image as D:\ , unknown in those days, a D, so that's probably the reason the saves were written on C root, or something , whatever.
To keep it short, even if you run the game from d:\ in dosbox, the game can only write the saves on the root, thus C:\
You should try to doing a normal mount, means mount floppies as A, not as D ,probably ... whatever.
In the ol'dos days drives were:
Floppy A (and B)
HD C
CD D
It's always advisable to use those drive letters.
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Last edited by dosraider; 29-03-2011 at 12:16 AM.
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Old 30-03-2011, 02:31 AM   #5
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Quote:
Originally Posted by dosraider View Post
The game is meant to run from floppy drive, in those times the compy was also booted from floppy, remember(or not)?
First off X 3. Some of my first programs were written by blacking out the correct indexes on punch cards, feeding those into a translator mahicne, which would then spit out a perforated length of paper tape. This tape was then fed into another machine which would load the computer with your program. It was a nightmare to debug and run multiple times. So yeah, I fondly remember the floppy drive days.

One of the statements from my original post and the first line of the snippet you quoted still remains: drive letter designation does not matter in this instance. Thank you for the image and feedback though. Both just reaffirmed what I thought may have been a problem but actually isn't. I still stick with the c/d drive naming standard unless I feel that may be part of the problem. Then I experiment with different drive letters.

The elements for this particular game:
- You need to have a legitimate img file imgmounted as a -t floppy drive if you want to write or overwrite your save games. Using a regular directory as a -t floppy does not work.
- The img file used can be anything, as long as it is a legitimate img file. This file is read from but never written to.
- You do not need to have a img - t floppy drive mounted to load save games, just to write or overwrite saves.
- The file named "game" (no extension) must exist in order to load or save any game, otherwise the application does not recognize the existence of a save disk.
- The size or content of the img file does not seem to matter, just that it is imgmounted as a -t floppy.

The file size for your mist.img is 1.44m, which is fine and it works as it should. However, since the last line in the list above is true, I found it is just much smaller and simpler to use a 160k empty img file since it is not written to anyway. I tried using an img file with the "game" file and even some actual previously saved games written to it, but the application still wouldn't touch it. I mean it worked, but the game still insisted I needed to initialize my save disk.

To me, the most humorous thing about this was that I've spent more time trying to work this out in my head and with my computer than I actually spent playing and solving The Mist. Although, come to think of it, I never would have finished the game if I hadn't been able to save in the first place.

One last thing: Is what r.u.s.s. posted actually true? You ARE responsible for dosbox not being able to natively support mounting of multiple floppy images ?
Thanks!
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Old 30-03-2011, 07:12 AM   #6
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Quote:
Originally Posted by Ohne Mitleid View Post
- You need to have a legitimate img file imgmounted as a -t floppy drive if you want to write or overwrite your save games. Using a regular directory as a -t floppy does not work.
- The img file used can be anything, as long as it is a legitimate img file. This file is read from but never written to.
- You do not need to have a img - t floppy drive mounted to load save games, just to write or overwrite saves.
That will be because dosbox's floppy hardware emulation isn't 100% when you mount a folder as floppy.
A bit (little bit, yes) the same as when you mount a folder as CD drive in stead of an image.

Quote:
Originally Posted by Ohne Mitleid View Post
One last thing: Is what r.u.s.s. posted actually true? You ARE responsible for dosbox not being able to natively support mounting of multiple floppy images ?
...... somewhere yes, but the decision to retrieve that function wasn't mine, I only pointed to some problems with the multiple floppy mount in the days I did some dosbox compatibilty testruns. (Mainly for Data).
So the dosbox devs (again, I'm not part of that group) decided to retrieve it.
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