As far as a quick glance went it's a proprietary file format so I guess there is no open source code to read the files. And it doesn't seem as if there are many files around...

One can read a it of MESS code, as Sarayan reverse engineered it, Also they released the source code at one time (after sarayan's REing): http://www.softpres.org/news:2011-10-15 (and is stillavailable)

Yes the code is mostly open from what I can see. However, I'm not sure how compatible it would be with DosBox due to the conflict with GPL. I am a true believer in GPL, but I want the IPF specification to be used since it's the current best image format for low level magnetic disk information. Maybe the difference can be resolved as an external plugin or similar.

This topic is highly relevant to my interests, so here are my 2 cents on it.

I've recently bought a KryoFlux for DOS game preservation purposes, as it represents the state of the art in that area and I have quite a lot of preserving to do. As part of that preservation effort I intend to submit them to the Software Preservation Society, who will create IPF files out of the KF stream files and send them back to me. Unfortunately, the IPF files will just sit on my hard drive from then on, since no DOS emulator supports them.

As the preeminent DOS emulator, DOSBox should definitely support IPF at some point. The reasoning is somewhat philosophical. Allow me to explain.

Any mention of "abandonware" or pirated games is highly frowned upon here. The developers seem unanimous in their opinion that DOSBox is intended for playing games you legally own, and the community opinion here on the forums is mostly the same. That's fine.

Now, as time goes on, it becomes more and more difficult for people to actually get their legally owned games into DOSBox, because the hardware to read the media becomes more and more scarce. Floppy drives are already as good as dead on new machines, and optical drives are steadily moving in that direction as well. USB versions of both are readily available for now, but that's not sufficient. First, you can't get a 5.25" USB drive. Second, you can't create DOSBox-supported images of floppies that have physical copy protection by using a USB floppy drive, so you need specialty hardware like KryoFlux or an actual DOS PC equipped with software like TeleDisk and the necessary floppy drives. (I'm lucky to have both setups.)

After considerable investment and/or effort, you now have shiny new copy protection-preserving floppy images... that DOSBox can't use. The only realistically available options to the user at this point are to give up, to resort to cracking (not illegal, but good luck finding a crack for a game made in the 80s or 90s), or piracy. (Owning a period PC that can play ye olde games is not a practical option, would do nothing to safeguard against bit rot of the original disks and the hardware would eventually fail anyway. Emulation is the only viable long term option.)

Here's the actual philosophical/ideological bit. How strong are your convictions about the use of DOSBox for legally owned games only, and how willing are you to demonstrate those convictions? Adding IPF support would be an excellent demonstration: here, finally, is a way for you to play games you own that you previously legally couldn't. It's not an easy way, but at least it's there. You could always point to it if someone challenges your anti-abandonware stance. (TeleDisk .TD0 support has also been discussed before, but going forward it will become less and less relevant, while the user base of KryoFlux will only grow.)

The prevalence of piracy cannot be helped, and even non-copy protected games will also still be pirated. Welcome to the real world, etc. But DOSBox would still be making a stand for the things the developers and the community profess to believe in. That would be commendable.

Now for some practical matters. The licensing scheme of the SPS IPF libraries is a bit exotic (modified MAME license IIRC), but GPL software like WinUAE are able to use it by relying on users installing the IPF user library from http://www.softpres.org/download (a bunch of important documentation is also available there).

While it's an extra step for the user, this is relatively unobtrusive from the DOSBox code viewpoint. IPF support implemented in this manner does not replace the existing floppy drive emulation code, but instead the library emulates a real floppy drive and feeds the client program the data it requests (this may be technically a tad inaccurate, but that's the overall gist I got from reading the KryoFlux forums where SPS folks hang out).

IPF images are read-only, so one significant new feature DOSBox would need is write shadowing, WinUAE style. The preservation of pristine disk images this allows, whether IPF or just plain IMA/IMG, would be a great addition in any case.

Finally, there's the overall positive halo effect on the whole retro DOS scene. DOSBox adding support for IPF would be a significant increase of potential IPF users -> sales of KryoFlux would increase, supporting the SPS -> more games would get sent to SPS and preserved. It's a win-win-win situation 😉

That's about it. I hope you recognize the value of IPF support. If you don't have the personal interest or development time available, I ask that you consider something like making IPF support for DOSBox a Google Summer Of Code project.

The concept of DOSBox is firmly rooted in the GPL and open source. The developers are trying to rid themselves of any vestiges of non GPL-MAME code. It is simply contrary to the aim of DOSBox to have most of DOSBox released under the GPL and some portions released under a different license. It could see introduction in unofficial ports of DOSBox.

Regarding the IPF, the first issue with implementing it is that DOSBox does not fully, if at all, emulate the NEC 765 Floppy Controller. DOSBox instead emulates Int 13h floppy writes and DOS calls. The copy protection schemes which the IPF seeks to preserve rely on the behavior of that controller. So there is the first obstacle.

Second, due in part to its high price and limited appeal, relatively few DOS gamers own a Kyroflux. Why bother implementing a feature that only 10-15 people may use?

Third, there are no tools available to the public to turn KF streaming files into IPF files, and even less support if you actually want to rewrite them to a disk. Also, if its not an Amiga game, especially a pristine one not yet in the SPS, good luck getting attention.

If you look, there are a fair number of cracks and programs to crack disk based floppy protections. Naturally they vary widely in quality.

As you indicate, the IPF format may not fully public.

In short, Kyroflux is not a good solution for DOS gamers at this time, and judging by the antipathy to any platform not released by Commodore or Atari, it may never be.

What he's saying is that given that most PC games before 1988 had on-disk copy protection, requiring them to be cracked exposes the whole "we don't support copyright infringement" attitude as the sanctimonious charade that it is. And I whole-heartedly agree.

It is unfortunate that certain compromises are commonly relied upon for the running of certain older commercial software which is intended to be used only with original media. That does not excuse anyone from pirating such software after the protection has been circumvented.

So how exactly are you supposed to run a keydisk-protected game in DosBox without "pirating", that is, infringing on copyrights? Either ...

1. you have the original media which you transfer, removing the copy protection yourself (which is copyright infringement);
2. you have the original media but instead of transferring it, you download a cracked copy from the internet (also copyright infringement);
3. or you download a cracked copy from the internet without owning the original media (also copyright infringement)?

Unless DosBox has a way of running protected games in their unaltered state, the argument could be made that DosBox encourages copyright infringement by requiring the removal of copy protection. Stating that keydisk-protected games are officially "unsupported" would be a lie since many games that are only legally available with keydisk protection are listed in DosBox' compatiblity list as being supported.

If adding Kryoflux or IPF support is too much effort, at least the simple TeleDisk format should be supported. Although that one doesn't fully reproduce the low-level information, it will be sufficient for running games using all the major disk copy protection schemes found in PC games. (The reason it's usually listed as not supporting i.e. Sierra AGI disks is that the PC can't write bad CRCs on purpose, even as the image format itself supports them.) The TeleDisk utility is also comparatively easy to use and requires no additional hardware to create image files.

4. you run them from the original floppy...

That obviously doesn't work with copy-protected disks. You tried being a smartass and failed.

If you boot in Dosbox, it works fine. Keep it civilized, don't be an ass

And just how are you supposed to "boot" in DosBox and still have access to the host computer's real a: drive in order to "run them from the original floppy"?

If you mount a before the real drive a is still passed through as far as I remember when I still had a floppy drive

Huh? No, it doesn't. "boot" only works with image files, not mounted directories. Running "mount a a:\" or "mount b a:\" then i.e. "boot dos33.ima" effectively unmounts the real drive a. And running "mount" after "boot" obviously doesn't work, as real DOS knows no "mount" command.

as far as I remember when I still had a floppy drive

So you haven't actually tried. I have! "solution 4" does NOT work.

I'm pretty sure I had a working a drive in dosbox when I booted from a hard drive image.
So I have tried it's just been a while as in years, since I tried.
Again, don't be an ass (accusing me of lying, calling me a smartass), we can discuss things civilized. Your way of discussing things only leads to flames, topic closing and tat's that then with this glorious idea.

I'm pretty sure I had a working a drive in dosbox when I booted from a hard drive image.

Even if that were the case, it wouldn't solve the problem of using copy-protected floppy disks, as MOUNT only mounts files and directories, not sectors. You need sectors for copy protection, not files. MOUNT doesn't suddenly start mounting sectors instead of files just because you boot from a hard disk image.

So I have tried it's just been a while as in years, since I tried.

But have you tried using a copy-protected floppy disk? That is the issue.

It had some kind of copy protection. Don't know which kind, perhaps not THAT kind.

Good luck with your goal. Since you don't seem to attract any dosbox developers, get on coding support yourself. Or try to convince other dos emu developers.

You know what, before going deeper into this, you should compile a list of games that *really* need this imaging, for which normal images made in dos with a good floppy image program, do not work in dosbox. This would surely help the developers much more if they decide to go this route. After all, they need to test these things and therefore need good test cases.

Dominus wrote:

You know what, before going deeper into this, you should compile a list of games that *really* need this imaging, for which normal images made in dos with a good floppy image program, do not work in dosbox. This would surely help the developers much more if they decide to go this route. After all, they need to test these things and therefore need good test cases.

He means all disk-based copy protected games, except for maybe some that use particularly simple forms of protection (i.e. enough so that DISKCOPY would not work, but a straight sector dump like an image program would). Teledisk is not an ordinary disk imaging program. IBM PCE does support the Teledisk format. If you want to avoid cracking, then for several hundred games you need a better disk imaging tool than Winimage.

All those Retrograde Station Booters, they were cracked so they could work in a standard image format.

One wonders under the DMCA whether even the Kyroflux is legal to manufacture and distribute after October, 2009.