Re: [Freedos-user] Dosemu on its own - does it exist?
I'm almost positive I saw the folks that made vmix producing an open source version of vmix, though I don't remember if it was called vmix or not. This was several years ago, (probably around the 2010 time frame). I don't know if I ever bookmarked it, but if I did, it's gone now, I checked my bookmarks, and couldnd't find it anywhere. Also, as mentioned before, vmix is now a video software, so that adds to the complication of hunting for the source urls. I didn't pay much attention at the time other than to go take a look, but when I looked, it wasn't ready for stand-alone use yet, so I forgot about it until this topic came up again. I'm wondering if vmm386 is the project this became, and that's why that name stuck in my head. I've not checked the vmm386 documentation to see if that's the case though. Sorry I don't have more information about it. On 3/31/2023 6:42 AM, Liam Proven wrote: On Wed, 29 Mar 2023 at 15:33, wrote: Yep, sorry, misremembered the name. It's vmix, and as far as I know, the last version was 2.67, and you can grab it here: This is very interesting. Just about lost to history and there are almost no mentions of it anywhere now. So if I read your multiple emails correctly, you are saying that it got made open source in the end? Is that right? ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Wed, 29 Mar 2023 at 15:33, wrote: > > Yep, sorry, misremembered the name. It's vmix, and as far as I know, > the last version was 2.67, and you can grab it here: This is very interesting. Just about lost to history and there are almost no mentions of it anywhere now. So if I read your multiple emails correctly, you are saying that it got made open source in the end? Is that right? -- Liam Proven ~ Profile: https://about.me/liamproven Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com Twitter/LinkedIn: lproven ~ Skype: liamproven IoM: (+44) 7624 277612: UK: (+44) 7939-087884 Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053 ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
One more, (unless I can find the opensource links, not having much luck there, since a video software took the name vmix some years ago, and all links I've found point to that, not to the dos software, though it's possible I was mixed up, because vmm386 was based on vmix, though I've not looked at the docs to see if that's the case or not. Anyway, version 2.90 of vmix is here: http://cd.textfiles.com/goldmedal/volume3/UTILS2/VMIX290.ARJ On 3/29/2023 10:47 AM, tsie...@softcon.com wrote: Found a later version. I'd forgotten what the latest version was. Here's a link to version 2.85. http://ftp.lip6.fr/pub/pc/garbo/pc/sysutil/vmix285.zip Hope that helps. On 3/29/2023 6:52 AM, Liam Proven wrote: On Wed, 29 Mar 2023 at 00:53, wrote: The original version of vmm386 was a fantastic dos multitasker, I never heard of that one before! Do you have any more info or links? ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
Found a later version. I'd forgotten what the latest version was. Here's a link to version 2.85. http://ftp.lip6.fr/pub/pc/garbo/pc/sysutil/vmix285.zip Hope that helps. On 3/29/2023 6:52 AM, Liam Proven wrote: On Wed, 29 Mar 2023 at 00:53, wrote: The original version of vmm386 was a fantastic dos multitasker, I never heard of that one before! Do you have any more info or links? ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
Yep, sorry, misremembered the name. It's vmix, and as far as I know, the last version was 2.67, and you can grab it here: http://cd.textfiles.com/toomuch/PASCAL/VMIX267.ZIP Sorry for the mixup there, hope it's useful though. On 3/29/2023 6:52 AM, Liam Proven wrote: On Wed, 29 Mar 2023 at 00:53, wrote: The original version of vmm386 was a fantastic dos multitasker, I never heard of that one before! Do you have any more info or links? ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Wed, 29 Mar 2023 at 00:53, wrote: > > The original version of vmm386 was a fantastic dos multitasker, I never heard of that one before! Do you have any more info or links? -- Liam Proven ~ Profile: https://about.me/liamproven Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com Twitter/LinkedIn: lproven ~ Skype: liamproven IoM: (+44) 7624 277612: UK: (+44) 7939-087884 Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053 ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Wed, 29 Mar 2023 at 00:20, Rugxulo wrote: > > IIRC, DR-DOS 7.03 (circa 1999) had task swapping for 286s and > preemptive multitasking for 386s (TASKMGR.EXE). But you had to use > their DR EMM386.EXE (no HIMEM.SYS needed) with their built-in DPMI > enabled. That's correct. > (It had a lot of bundled / hidden .VXDs or whatever.) Did it? This is news to me. Do you have any links or anything? I'd like to know more. > It was > limited to 64 MB per task (despite the false claim of XMS v3 support). Interesting. I didn't know that. Plenty for most DOS apps, though! > And no FAT32 support. It does now. Both the DR DOS Enhancement Project added this, and later the commercial DR-DOS too. > They stopped selling DR-DOS online back in 2018, right? I don't know the date. > But I'd be > surprised if DR-DOS was still considered a true derivative of CP/M-86. I am not sure. I may have to try to contact Mr Sparks myself. > Almost all of the CP/M support was probably stripped out. I don't think it supports CP/M binaries any more but then again that hasn't mattered in 30+ years and I'm not sure even Multiuser DOS does any more. If the OS was derived from CP/M, does it matter if it still supports CP/M apps? > I'm overly > skeptical about that. Which part? > (The so-called "OpenDOS" was only kernel and > shell for "non-commercial use", AFAIK That's right. > and wasn't even patched with > the latest Novell fixes.) I think those were re-discovered and re-incorporated later on. So, not in the OpenDOS version, which had to re-implement the fixes. > Minix 2.0.4 (circa 2003) could run atop FAT16 (e.g. DOS). Um. This seems a veer into an unrelated direction to me, but maybe I am missing something. Now, with full read-write NTFS support in kernel 5.15 and later, you can boot and run Linux from NTFS. So what, though? That's just a filesystem. No underlying OS is present. > Or just develop in standard C (or Modula-2) atop Minix [DOSMinix, > booting atop FAT], with its multitasking for faster development, and > later transfer your sources to DOS to compile natively. Seems a lot of work TBH. > You could also run old Slackware 11 (ZipSlack) atop FAT (Linux 2.4 > kernel, UMSDOS). IIRC, it had GCC 3.4.6. Maybe even an old DOSEMU > would run there. That is true. > Memory is such a mess (and I don't mean 16-bit). So many things have > corner cases or bugs. Yes it is. But the key question is, how many DOS apps are still around? Does anyone care if 1-2-3 r3 doesn't work, so long as popular games do, say? And do gamers care about multitasking? I doubt it. > In case it wasn't obvious, I did buy DR-DOS (online in 2004) They sent me a review copy. > but I > rarely used their multitasking. Same. > The main potential uses (to me) would > be 1). finding files in the background (or grepping), 2). compiling > some sources, or 3). file compression. But I rarely needed to care. True. I found it useful for formatting media (i.e. floppies) in the background, and for rendering big fractals while still being able to use the computer. :-) > (Most people would also prefer listening to music or downloading > files.) Yes, true, but does this apply to DOS use? > As a workaround, locally in FreeDOS, I always (weakly) tried to > simplify things (build processes), use speedy tools, better > algorithms, etc. Running atop RAM disk and/or cache also helps a ton. > DJGPP can be quite slow (and worse with LFNs enabled). You know, if > everything is quick and efficient (and accurate), you don't need to > multitask as much. (But I hate brittle makefiles that are easy to > break. I'd rather just rebuild slowly from scratch via shell script.) Good points. > There are some brilliant apps that use the mouse (e.g. JED), but I > rarely relied on it. Oh! That surprises me. It's quite important to me. > Sound is the weakest link in DOS (and probably > not crucial to "real work" for most people). Agreed. I don't care myself, but I'm not a gamer. > Network can be very > useful but isn't well-supported (lack of packet drivers). True. > That vaguely reminds me. I think I once suggested someone use FreeBSD > and QEMU as a sort of way to multitask DOS. You don't even need X11 > installed. The minimum (last I checked) for FreeBSD was 64 MB of RAM > (486 DX or better), but of course probably much more required with a > guest running. (They've had their own hypervisor, bhyve, since 2014 or > so, using VT-X [EPT] I had to look up this abbreviation. I don't think bhyve needs VT-X v2. > but I don't specifically know if they ever > bothered running DOS with it. Me neither. But FreeBSD isn't much lighter than Linux, TBH. > I think they did have some shims for > BIOS-based Windows. Oh? I have not looked. I will try to find out. > But stick with the QEMU package for now. Or KVM? Or Xen? > Even Minix 3, formerly with lots of funding, still dried up in 2016. Dr Tanenbaum retired. > It's sad, but most people don't want a 32-bit only OS that
Re: [Freedos-user] Dosemu on its own - does it exist?
The original version of vmm386 was a fantastic dos multitasker, even to the point of allowing multiple dos programs write to the screen via bios calls. I wanted to use it for some things back when it was new shareware, and I even called and got to talk to the developer. The problem for me was that my screen reader intercepted the dos interrupts for writing to the screen, so when I was using vm386, the screen reader would talk both programs simultaneously. Needless to say, that made for rather confusing operations. It worked just fine though with programs that bypassed the bios calls, and just wrote to video memory, since those my screen reader didn't intercept. On the other hand, it made the programs harder to use, so I didn't spend a lot of time using vm386 myself, but I did hear of others using it for all kinds of things, including running bbs software to handle multiple lines. I know they've tried to make an openssource version of it not so long ago, but that's not from the original sources so far as I could tell, so I don't believe it will/does work quite as well as the original program does. On the other hand, there's nothing stopping someone from grabbing a copy and installing it and running it on a machine nowadays, since the folks that made it started the opensourcing process, I doubt anyone would complain if someone used it these days. On 3/28/2023 7:17 PM, Rugxulo wrote: Hi, On Tue, Mar 28, 2023 at 8:47 AM Liam Proven wrote: DR DOS does have some source code available, and includes TaskMaster, which can do full-screen multitasking of DOS sessions. This *does* work on bare modern hardware in my testing. IIRC, DR-DOS 7.03 (circa 1999) had task swapping for 286s and preemptive multitasking for 386s (TASKMGR.EXE). But you had to use their DR EMM386.EXE (no HIMEM.SYS needed) with their built-in DPMI enabled. (It had a lot of bundled / hidden .VXDs or whatever.) It was limited to 64 MB per task (despite the false claim of XMS v3 support). And no FAT32 support. Lineo/DeviceLogics president and CEO Bryan Sparks said all CP/M derivatives are free to use, modify and distribute last year. DR DOS is a derivative of CP/M-86 which is a derivative of CP/M. I think it could be used. They stopped selling DR-DOS online back in 2018, right? But I'd be surprised if DR-DOS was still considered a true derivative of CP/M-86. Almost all of the CP/M support was probably stripped out. I'm overly skeptical about that. (The so-called "OpenDOS" was only kernel and shell for "non-commercial use", AFAIK, and wasn't even patched with the latest Novell fixes.) It seems to me that if the sources of Multiuser DOS could be obtained, and if it's covered by Mr Sparks' edict, then it would give a lot of what people want from a DOS nowadays. Minix 2.0.4 (circa 2003) could run atop FAT16 (e.g. DOS). It wasn't perfect but still quite good. It could multitask its own binaries (a.out variant). I've been wanting to try to build 8086tiny (ecm's fork) under it. But even Minix choked on machines with lots of RAM. I don't think it booted atop FAT32 either. I personally wanted to try again under VirtualBox one of these days. Or just develop in standard C (or Modula-2) atop Minix [DOSMinix, booting atop FAT], with its multitasking for faster development, and later transfer your sources to DOS to compile natively. You could also run old Slackware 11 (ZipSlack) atop FAT (Linux 2.4 kernel, UMSDOS). IIRC, it had GCC 3.4.6. Maybe even an old DOSEMU would run there. Multiuser DOS was the last and final descendant of CP/M. It's a native 32-bit OS, multitasking but DOS compatible, with FAT32 support. It supports up to 4GB of RAM and apps can get both EMS and XMS services. Memory is such a mess (and I don't mean 16-bit). So many things have corner cases or bugs. In case it wasn't obvious, I did buy DR-DOS (online in 2004), but I rarely used their multitasking. The main potential uses (to me) would be 1). finding files in the background (or grepping), 2). compiling some sources, or 3). file compression. But I rarely needed to care. (Most people would also prefer listening to music or downloading files.) As a workaround, locally in FreeDOS, I always (weakly) tried to simplify things (build processes), use speedy tools, better algorithms, etc. Running atop RAM disk and/or cache also helps a ton. DJGPP can be quite slow (and worse with LFNs enabled). You know, if everything is quick and efficient (and accurate), you don't need to multitask as much. (But I hate brittle makefiles that are easy to break. I'd rather just rebuild slowly from scratch via shell script.) It has modest hardware support: CD, DVD, sound, mouse, a few other things. It supports a few network cards, and can talk TCP/IP and SMB. There are some brilliant apps that use the mouse (e.g. JED), but I rarely relied on it. Sound is the weakest link in DOS (and probably not crucial to "real work" for most people). Network can be very useful but
Re: [Freedos-user] Dosemu on its own - does it exist?
Hi, On Tue, Mar 28, 2023 at 8:47 AM Liam Proven wrote: > > DR DOS does have some source code available, and includes TaskMaster, > which can do full-screen multitasking of DOS sessions. This *does* > work on bare modern hardware in my testing. IIRC, DR-DOS 7.03 (circa 1999) had task swapping for 286s and preemptive multitasking for 386s (TASKMGR.EXE). But you had to use their DR EMM386.EXE (no HIMEM.SYS needed) with their built-in DPMI enabled. (It had a lot of bundled / hidden .VXDs or whatever.) It was limited to 64 MB per task (despite the false claim of XMS v3 support). And no FAT32 support. > Lineo/DeviceLogics president and CEO Bryan Sparks said all CP/M > derivatives are free to use, modify and distribute last year. DR DOS > is a derivative of CP/M-86 which is a derivative of CP/M. I think it > could be used. They stopped selling DR-DOS online back in 2018, right? But I'd be surprised if DR-DOS was still considered a true derivative of CP/M-86. Almost all of the CP/M support was probably stripped out. I'm overly skeptical about that. (The so-called "OpenDOS" was only kernel and shell for "non-commercial use", AFAIK, and wasn't even patched with the latest Novell fixes.) > It seems to me that if the sources of Multiuser DOS could be obtained, > and if it's covered by Mr Sparks' edict, then it would give a lot of > what people want from a DOS nowadays. Minix 2.0.4 (circa 2003) could run atop FAT16 (e.g. DOS). It wasn't perfect but still quite good. It could multitask its own binaries (a.out variant). I've been wanting to try to build 8086tiny (ecm's fork) under it. But even Minix choked on machines with lots of RAM. I don't think it booted atop FAT32 either. I personally wanted to try again under VirtualBox one of these days. Or just develop in standard C (or Modula-2) atop Minix [DOSMinix, booting atop FAT], with its multitasking for faster development, and later transfer your sources to DOS to compile natively. You could also run old Slackware 11 (ZipSlack) atop FAT (Linux 2.4 kernel, UMSDOS). IIRC, it had GCC 3.4.6. Maybe even an old DOSEMU would run there. > Multiuser DOS was the last and final descendant of CP/M. It's a native > 32-bit OS, multitasking but DOS compatible, with FAT32 support. It > supports up to 4GB of RAM and apps can get both EMS and XMS services. Memory is such a mess (and I don't mean 16-bit). So many things have corner cases or bugs. In case it wasn't obvious, I did buy DR-DOS (online in 2004), but I rarely used their multitasking. The main potential uses (to me) would be 1). finding files in the background (or grepping), 2). compiling some sources, or 3). file compression. But I rarely needed to care. (Most people would also prefer listening to music or downloading files.) As a workaround, locally in FreeDOS, I always (weakly) tried to simplify things (build processes), use speedy tools, better algorithms, etc. Running atop RAM disk and/or cache also helps a ton. DJGPP can be quite slow (and worse with LFNs enabled). You know, if everything is quick and efficient (and accurate), you don't need to multitask as much. (But I hate brittle makefiles that are easy to break. I'd rather just rebuild slowly from scratch via shell script.) > It has modest hardware support: CD, DVD, sound, mouse, a few other > things. It supports a few network cards, and can talk TCP/IP and SMB. There are some brilliant apps that use the mouse (e.g. JED), but I rarely relied on it. Sound is the weakest link in DOS (and probably not crucial to "real work" for most people). Network can be very useful but isn't well-supported (lack of packet drivers). That vaguely reminds me. I think I once suggested someone use FreeBSD and QEMU as a sort of way to multitask DOS. You don't even need X11 installed. The minimum (last I checked) for FreeBSD was 64 MB of RAM (486 DX or better), but of course probably much more required with a guest running. (They've had their own hypervisor, bhyve, since 2014 or so, using VT-X [EPT], but I don't specifically know if they ever bothered running DOS with it. I think they did have some shims for BIOS-based Windows. But stick with the QEMU package for now.) > It's not a true DOS, it can't run DOS device drivers, and has > functionality that's irrelevant today, such as serial terminal > support. But if someone could chase down a final version of the > source, it could have some obsolete stuff stripped out (NetBIOS and > IPX/SPX support, RS/232 terminals, etc.) and could be useful to > someone somewhere. > > I tried to contact 3 or 4 vendors of Multiuser DOS mentioned in my > article. Most didn't reply. Even Minix 3, formerly with lots of funding, still dried up in 2016. It's sad, but most people don't want a 32-bit only OS that doesn't have USB support (very complex). Well, except Intel for its Management Engine. ;-) I was always impressed by Minix and how much they accomplished, even in the 2.x days. I'm sure there are dozens of improvements we could make to
Re: [Freedos-user] Dosemu on its own - does it exist?
On Tue, 28 Mar 2023 at 09:23, tom ehlert wrote: > > we have DeskView386 which does exactly what you describe. Do you mean DESQview? It exists but with multiple drawbacks. • DESQview 386 means DESQview + QEMM386. Two separate products. • I have both. I have been unable to get QEMM to run on bare metal on any machine as new or newer than a Core 2 Duo. • Neither DESQview nor QEMM are FOSS or even freeware. Symantec says it lost the source. DR DOS does have some source code available, and includes TaskMaster, which can do full-screen multitasking of DOS sessions. This *does* work on bare modern hardware in my testing. Lineo/DeviceLogics president and CEO Bryan Sparks said all CP/M derivatives are free to use, modify and distribute last year. DR DOS is a derivative of CP/M-86 which is a derivative of CP/M. I think it could be used. https://www.theregister.com/2022/08/04/the_many_derivatives_of_cpm/ However saying that, are there any new DOS device drivers in the 21st century? Will there be? It seems to me that if the sources of Multiuser DOS could be obtained, and if it's covered by Mr Sparks' edict, then it would give a lot of what people want from a DOS nowadays. Multiuser DOS was the last and final descendant of CP/M. It's a native 32-bit OS, multitasking but DOS compatible, with FAT32 support. It supports up to 4GB of RAM and apps can get both EMS and XMS services. It has modest hardware support: CD, DVD, sound, mouse, a few other things. It supports a few network cards, and can talk TCP/IP and SMB. It's not a true DOS, it can't run DOS device drivers, and has functionality that's irrelevant today, such as serial terminal support. But if someone could chase down a final version of the source, it could have some obsolete stuff stripped out (NetBIOS and IPX/SPX support, RS/232 terminals, etc.) and could be useful to someone somewhere. I tried to contact 3 or 4 vendors of Multiuser DOS mentioned in my article. Most didn't reply. -- Liam Proven ~ Profile: https://about.me/liamproven Email: lpro...@cix.co.uk ~ gMail/gTalk/FB: lpro...@gmail.com Twitter/LinkedIn: lproven ~ Skype: liamproven IoM: (+44) 7624 277612: UK: (+44) 7939-087884 Czech [+ WhatsApp/Telegram/Signal]: (+420) 702-829-053 ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
> Hi, > I am a bit late but... +1 > On Wed, 2 Sept 2020 at 15:50, ZB wrote: > If I'm correct, Dosemu uses "virtual x86 mode" of 386 and later processors. > But Dosemu of course needs "host OS". > I wonder does there exist any utility that offers "virtual x86 mode" and > acts as "host" by itself? Suppose we have (quite modest for today) computer > with 386/486 and 4 MB RAM. Theoretically it should be possible to run quite > comfortably four DOS "instances" each one having 1 MB just for itself - and, > say, switching among them with - like among consoles in Linux. > So concentrating on using DOS - because 486 is much too "weak" for Linux of > today - I mean utility whose duty is just to switch CPU into "virtual x86 > mode", split RAM among established "instances" and then just share hardware > resources (keyboard, CD-ROM, video, sound... everything) among them. we have DeskView386 which does exactly what you describe. Tom ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
Hi, I am a bit late but... On Wed, 2 Sept 2020 at 15:50, ZB wrote: > If I'm correct, Dosemu uses "virtual x86 mode" of 386 and later processors. > But Dosemu of course needs "host OS". > > I wonder does there exist any utility that offers "virtual x86 mode" and > acts as "host" by itself? Suppose we have (quite modest for today) computer > with 386/486 and 4 MB RAM. Theoretically it should be possible to run quite > comfortably four DOS "instances" each one having 1 MB just for itself - > and, > say, switching among them with - like among consoles in Linux. > > So concentrating on using DOS - because 486 is much too "weak" for Linux of > today - I mean utility whose duty is just to switch CPU into "virtual x86 > mode", split RAM among established "instances" and then just share hardware > resources (keyboard, CD-ROM, video, sound... everything) among them. > It has had many names (DOS386.EXE, WIN386.EXE), but we usually know it as VMM32.VXD. Hardware resource sharing is handled in individually loadable modules called VxD's, that simulate that every DOS machine has the entire (DOS/BIOS) resources for itself. No idea - maybe it had been aleady created, just I didn't stumble upon it > yet? > You have (Windows 9X is a privileged GUI that runs in VM0). Aitor ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
Hello ZB, Actually I was hoping it could be "thinner layer"... but, as I wrote, only know I'm trying to find out, how exactly "virtual x86 mode" works Basically --- as Eric Auer sort of explained --- a "virtual 8086" is a special kind of unprivileged protected-mode task, that runs under a 32-bit protected-mode OS (or, if there is no actual OS, a monitor program). The memory mappings of the "virtual 8086" --- that is, how the "virtual" 1 MiB address space actually maps to physical memory --- and the device I/O, are governed by the 32-bit OS. Thank you! -- https://github.com/tkchia ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Thu, Sep 03, 2020 at 12:52:32PM -0400, dmccunney wrote: > What you are talking about are full blown Virtual Machine setups. The > VM sits between the host machine's hardware and the OS to be > virtualized. Examples in the commercial software world include things > like VMWare Actually I was hoping it could be "thinner layer"... but, as I wrote, only know I'm trying to find out, how exactly "virtual x86 mode" works -- regards, Zbigniew ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Wed, Sep 2, 2020 at 9:50 AM ZB wrote: > > If I'm correct, Dosemu uses "virtual x86 mode" of 386 and later processors. > But Dosemu of course needs "host OS". > > I wonder does there exist any utility that offers "virtual x86 mode" and > acts as "host" by itself? Suppose we have (quite modest for today) computer > with 386/486 and 4 MB RAM. Theoretically it should be possible to run quite > comfortably four DOS "instances" each one having 1 MB just for itself - and, > say, switching among them with - like among consoles in Linux. What you are talking about are full blown Virtual Machine setups. The VM sits between the host machine's hardware and the OS to be virtualized. Examples in the commercial software world include things like VMWare, and in the open source world we have Oracle's Virtual Box. For that matter, Microsoft has a virtual machine setup, specialized for running more than one Windows instance. With a full VM, the *OS* can be virtualized as well as the applications running under the OS, because the "hypervisor" sits between the OSes and the hardware. I used VMWare at a former employer. We were a streaming video provider. Our preferred servers were 1u Dell rackmount units with dual 3ghz Xeon CPUs and 32GB RAM. Servers under VMWare were running CentOS, the open source flavor of Red Hat Enterprise Linux. (Linux is open source, and you can get the code free. What Read Hat sold was *support*.) Spinning up a new server under VMWare was a trivial exercise. (Depending on the OS. A co-worker had a *lot* of fun trying to spin up a virtualized WinXP instance...) We had load balancing on traffic coming into the servers, so requests got routed to whichever running server had the capacity. (And what we did did not require maintaining state and history, so new incoming requests could go to whichever server happened to be available.) The concept is an old one. I worked at a bank that was an IBM mainframe shop in the 80s. IBM had a virtual machine OS called VM/CMS. You could load other IBM mainframe OSes under it, and it imposed about 10% overhead. A popular use case was a shop currently running IBM's DOS/VSE OS who wanted to migrate to OS/MVS. Making the move was non-trivial. There were all manner of changes you needed to make to your workflow and your applications to do this. So you ran VM/CMS, brought DOS/VSE up under it in a production partition, and OS/MVS in a test partition. Normal workloads connected to the DOS/VSE instance. Applications being migrated and tested to make sure they ran as designed were in the test partition. Once migration was completed and fully tested to confirm everything worked correctly, DOS/VSE could be taken down and OS/MVS became the production environment. But as you might guess, you need a powerful machine to be able to support this usage, and server class machines generally have hardware designed to make it easy to run a VM. The goal is maximizing hardware usage. I went through that exercise at another employer with lots of dedicated servers for different purposes, some of which were barely used. Instead of adding more and more servers (which required more and more power and cooling) install VMWare and consolidate. It got nowhere because a British sister company had tried to do that and failed. I thought they simply didn't know what they were doing and we *could* do it, but the decision not to was made several levels above me. > So concentrating on using DOS - because 486 is much too "weak" for Linux of > today - I mean utility whose duty is just to switch CPU into "virtual x86 > mode", split RAM among established "instances" and then just share hardware > resources (keyboard, CD-ROM, video, sound... everything) among them. Just what do you mean when you say 486? They came in a variety of makes/models. A 486 *can* run Linux, with reasonable performance depending on what you want to do.. Mostly, you want to give it as much RAM as the machine can accommodate. Linux distros exist intended for older, less powerful hardware. You *might* be able to configure a Linux instance on that hardware that would let you multi-boot using Grub2 or the like, and pick which flavor of DOS you wanted to run that session. You almost certainly *won't* be able to have multiple different instances of DOS running simultaneously. > No idea - maybe it had been aleady created, just I didn't stumble upon it yet? It doesn't exist. See above for why. > regards, > Zbigniew __ Dennis ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
Hi! > At the moment I know next to nothing about that "virtual x86 mode" - and > I was hoping that CPU can be made to switch to that mode and then to boot > even different OS into each "instance" That is exactly what Windows does, but the instances are called tasks. Because DOS is not task-aware, Windows has to catch everything which DOS believes to be single-user and redirect it into multi-user :-) You can run dosbox as a DOS app with HX RT, but just one instance. The trick with virtual x86 mode is that it hides the protected mode and task details from the "instance", so creating vm86 tasks means extra work for the creator. For example emm386 puts itself into protected mode and transplants DOS into a vm86 task, but makes use of the fact that only a single instance of DOS exists. The emm386 of DR-DOS already contains some preparations for swapping tasks, which makes it more complicated. Tools like desqview also use protected mode and vm86 tasks to keep track of user interaction attempts of DOS and let you swap between several DOS apps, which must all run in full screen mode. They are more powerful than MS DOSSHELL which I believe to use no protected mode: It probably only intercepts BIOS calls to keep track of the hardware state expected by each app when you swap between them. By the way, DOSEMU2 is aiming to also work on Windows, not just on Linux. It has a built-in CPU emulation for situations where no vm86 tasks can be acquired. Seems common in our 64-bit age. Cheers, Eric ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
[Freedos-user] Dosemu on its own - does it exist?
Some possibilities, haven't checked them out myself Concurrent DOS 386 https://en.wikipedia.org/wiki/Multiuser_DOS#CCP/M-86 https://winworldpc.com/product/digital-research-con/386-3x PC-MOS/386 https://en.wikipedia.org/wiki/PC-MOS/386 https://github.com/roelandjansen/pcmos386v501 Currently hiding in the Arkansas Delta ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Wed, Sep 2, 2020 at 10:10 AM ZB wrote: > On Wed, Sep 02, 2020 at 03:56:26PM +0200, Mateusz Viste wrote: > > > https://en.wikipedia.org/wiki/DESQview > > Indeed I recall that name - but somehow never used it before. Does it do > exactly what I've described? Like - for example - I could "split" 486 into > four x86 CPUs, then I can use one instance to boot FreeDOS there, the second > one to boot DOS 6.22 (for comparison), the third one for, say, DR-DOS etc. No, you can't. I ran it, back in the day. Think of it as a multitasking character mode GUI shell running on top of DOS. You were *not* running multiple copies of *DOS*. You were running multiple *applications* under DOS at the same time. DOS was single-tasking. DV serialized access to it by the various DOS applications, so it was the single task DOS was supporting. It used round robin time slicing, doing a bit of work on each process running under it and moving to the next. It really wanted a (by the standards of the day) fast and powerful machine to be used effectively. A chap I knew back when was a BBS Sysop, and had four nodes of Wildcat BBS software (a popular choice back then) running on a single 25mhz AT clone with a 286 CPU. Other sysops found themselves running multiple PCs on a LAN if they wanted more than one node of the BBS at a time. You needed to experiment with DV to get settings correct to best support what you did, with allocation of foreground and background time slices being key. Conceptually, Windows 3.1 was the next step beyond DesqView. It was a multi-tasking bit-mapped GUI shell on top of DOS. The transition Windows faced was from 16 bit to 32 bit applications. Win95 made a start on that, but DOS was still under the hood. Win98 was the next step. DOS was still there because Win98 needed a real-mode *loader*, but once it was initialized and running, it took over all OS functions and DOS was out of the loop. Win2K was a fully virtualized 32 bit system, and had no need for DOS. (It *did* provide DOS emulation for folks who still wanted to run DOS programs wia the NTVDM DLL.) Win7 and later were aimed at 64bit systems. On a 64bit system, support for 16bit programs went away. If you really needed them, you ran some form of VM under Windows and ran the DOS programs in it. (The vDOS Plus package discussed here is essentially a VM for running 16bit DOS apps.) > Zbigniew __ Dennis ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Wed, Sep 02, 2020 at 04:23:47PM +0200, Mateusz Viste wrote: > I wonder how far one could get with just an emulated 8086 core, 640K of > mapped memory and a simulated BIOS. At the moment I know next to nothing about that "virtual x86 mode" - and I was hoping that CPU can be made to switch to that mode and then to boot even different OS into each "instance" -- regards, Zbigniew ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
No, it was application-level, and AFAIR it required the applications not to be too greedy about what they do. I think that what you describe now isn't possible without introducing some form of (expensive) emulation to avoid the different systems to fight for shared resources. At the very least it would require an emulation of a different BIOS for each instance. I wonder how far one could get with just an emulated 8086 core, 640K of mapped memory and a simulated BIOS. Perhaps it could run some early MDA-compatible software that was made before the "use hardware directly" era. Mateusz On 02/09/2020 16:08, ZB wrote: On Wed, Sep 02, 2020 at 03:56:26PM +0200, Mateusz Viste wrote: https://en.wikipedia.org/wiki/DESQview Indeed I recall that name - but somehow never used it before. Does it do exactly what I've described? Like - for example - I could "split" 486 into four x86 CPUs, then I can use one instance to boot FreeDOS there, the second one to boot DOS 6.22 (for comparison), the third one for, say, DR-DOS etc. ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
On Wed, Sep 02, 2020 at 03:56:26PM +0200, Mateusz Viste wrote: > https://en.wikipedia.org/wiki/DESQview Indeed I recall that name - but somehow never used it before. Does it do exactly what I've described? Like - for example - I could "split" 486 into four x86 CPUs, then I can use one instance to boot FreeDOS there, the second one to boot DOS 6.22 (for comparison), the third one for, say, DR-DOS etc. -- regards, Zbigniew ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
Re: [Freedos-user] Dosemu on its own - does it exist?
DOSemu relies on a number of Linuxisms, hence cannot be used as such kind of bootstrap. What you think about is called DESQview. https://en.wikipedia.org/wiki/DESQview Mateusz On 02/09/2020 15:48, ZB wrote: If I'm correct, Dosemu uses "virtual x86 mode" of 386 and later processors. But Dosemu of course needs "host OS". I wonder does there exist any utility that offers "virtual x86 mode" and acts as "host" by itself? Suppose we have (quite modest for today) computer with 386/486 and 4 MB RAM. Theoretically it should be possible to run quite comfortably four DOS "instances" each one having 1 MB just for itself - and, say, switching among them with - like among consoles in Linux. So concentrating on using DOS - because 486 is much too "weak" for Linux of today - I mean utility whose duty is just to switch CPU into "virtual x86 mode", split RAM among established "instances" and then just share hardware resources (keyboard, CD-ROM, video, sound... everything) among them. No idea - maybe it had been aleady created, just I didn't stumble upon it yet? ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
[Freedos-user] Dosemu on its own - does it exist?
If I'm correct, Dosemu uses "virtual x86 mode" of 386 and later processors. But Dosemu of course needs "host OS". I wonder does there exist any utility that offers "virtual x86 mode" and acts as "host" by itself? Suppose we have (quite modest for today) computer with 386/486 and 4 MB RAM. Theoretically it should be possible to run quite comfortably four DOS "instances" each one having 1 MB just for itself - and, say, switching among them with - like among consoles in Linux. So concentrating on using DOS - because 486 is much too "weak" for Linux of today - I mean utility whose duty is just to switch CPU into "virtual x86 mode", split RAM among established "instances" and then just share hardware resources (keyboard, CD-ROM, video, sound... everything) among them. No idea - maybe it had been aleady created, just I didn't stumble upon it yet? -- regards, Zbigniew ___ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
