idea for better DOS hardware support (i.e. audio, for instance) (#18855)

[ssybesma]

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ModEdit; related ticket: #18855: please add much better sound support for DOS VMs

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I have FreeDOS 1.3 RC-1 as a guest OS on Virtualbox 6.0.10
Works fantastic as a guest OS in some cases, but not in others. It's not FreeDOS' fault though. It was created with real PC hardware in mind.

I was told that Virtualbox uses a DMA-based approach to sound card emulation and doesn't use I/O addresses.

I have a DOS game (that came with FreeDOS) that doesn't play sound. That game tries to use I/O (ostensibly A220).

The thought came to me that because of Virtualbox's limited sound emulation (friendly to late '90s versions of Windows and beyond) that a pre-boot BIOS extension similar to the idea of OnTrack's DDO could be created to overcome this.
OnTrack's idea was to add function to the BIOS that was not already there. It allowed machines with older BIOS to recognize a larger HDD, but that idea can be put to other uses as well.

Is that idea even feasible?

Seems like this could be an answer to any DOS hardware issue that people run into with Virtualbox or any other similar host application.

[mpack]

Is that idea even feasible?

I don't see how. Ok, the VirtualBox BIOS would have a new function. What was your plan for getting everyone to modify their DOS software - their long dead and gone DOS software - to call an API that only exists on one platform?

[ssybesma]

No need for any users to modify their software.
A better implementation of 386 or 486 hardware including much better SoundBlaster support (the most common card installed on a motherboard besides a modem which almost nobody uses) can be done.
If DOSBox can somehow manage it, then it's not a stretch.
I offered an alternate solution being like an add-on or plug-in (or a special Extension Pack for DOS, or even an 'pre-boot' overlay something like the OnTrack DDO concept which is a BIOS extension).
Another thing that can be improved is video, specifically more modes like 43 and 50 line, and also SVGA up to at least 1024 x 768.
Right now the most important thing is audio.
If they can do that, it would make using DOS VMs easier and they would be a lot more versatile than DOSBox which only handles games.
DOS could see a revival among more people if it's made easier to use in a VM that supports it better. There's still valuable software out there that can be used in a business setting.
All that's needed is a VM host app that serves DOS better than any of them has before.

[andyp73]

The development of VirtualBox is driven by Oracle's paying customers and the open source version rides piggyback. I doubt that any of Oracle's customers have a need for any more functionality for DOS guests than is already present.

You could, if you wish develop the support (this is open source when all is said and done) and submit the patches back to Oracle or you could break out your cheque book and become a paying customer to see if that has any bearing on the features. If you go for the latter option, the starting price is $6,100.

-Andy.

[mpack]

No need for any users to modify their software.

You asked a very specific question: is a BIOS extension useful as a way of improving DOS support. I gave a very specific answer: no. See my previous answer for the details you ignored. I'm not into discussing the surrounding philosophy.

The idea that spurring a DOS revival is possible or should be a goal is slightly hilarious. DOS died over a quarter of a century ago, it was of its time and IME very few people remember it fondly. Ironically we do have a dev that might be one of those few, but I doubt even he is into rewriting DOS software with a market value of $0.

[ssybesma]

DOSBox is able to get it done so that sound works in DOS, so whatever they're doing can be incorporated into Virtualbox. It's not a horrendous stretch no matter what you say.

I don't know what you know (doesn't seem like this is your area of expertise), but the solution I suggested would in fact work.

Whatever Virtualbox provides as support can be supplemented in the Virtualbox app itself, or in a Extension Pack created specifically for DOS, or else within the guest if a 'pre-boot' BIOS extension (overlay) is loaded.

Anything can be done. I'm not into dismissing things outright. I realize you don't have any interest, so you're wasting my time and yours. I'm only interested in hearing from people who have a similar interest.

I will continue to try and drum up interest on this website from time to time.

[mpack]

As I said, I'm not into having a philosophical discussion. I asked you a simple question in my first reply, please answer it. The question was important, so please don't ignore it, don't gloss over it, and don't make any more irrelevant DOSbox comparisons.

As to my area of expertise, I've been a professional software developer for 39 years (scary when I calculate that). I've developed commercially available software for DOS and for every version of Windows from Win3 to Win10. I'm well aware of what would be required to allow DOS apps to use audio (*). I still have my day job, but I come here to relax.

(*) They can't. DOS apps didn't use sound cards unless they were specifically written that way, and since it wasn't part of the OS (neither DOS itself or the BIOS) they had to call a proprietary TSR driver provided by the sound card manufacturer. There is no audio API in a DOS era BIOS, so no DOS application will make calls to DOS or BIOS for that purpose. Yes you can add extra functions to the BIOS, yes you can add extra functions to the SoundBlaster driver (which would have to be written first, since VirtualBox doesn't provide one), but it would all be pointless since the DOS app was not written to ask the BIOS or driver to perform those extra functions.

[michaln]

DOSBox is able to get it done so that sound works in DOS, so whatever they're doing can be incorporated into Virtualbox. It's not a horrendous stretch no matter what you say.

Anyone can show how incompetent Oracle developers are by providing source code patches which implement the desired functionality. If the patches are of good quality and legally in the clear (i.e. not containing someone else's GPL code etc.), they will be very likely integrated into VirtualBox.