Hi Bernd, Jeremy, different virtual PCs seem to have different issues, but they are all useable and I am quite sure that users run Linux and Windows inside them without real problems. Why should we have to tell DOS users that only a certain and small subset of all virtual environments can do FreeDOS? After all, DOS is supposed to be EASY on the hardware...
In theory, there are only relatively few, clear problems: - DOS cannot see that it is part of a bigger desktop, so extra VM aware mouse driver comfort is missing. Not sure if it is bad at all. One may port drivers. - I know no VM which supports magic guest/host DOS drives (not counting DOSEMU, which maps any Linux directory to a DOS drive easily without extra drivers: No full VM...) - VMs might react in counterintuitive ways to attempts to save energy (e.g. OLD Bochs + FDAPM ran too fast) ACPI can also break, but FDAPM APMDOS only needs HLT. - VMs might simulate exotic network cards and those simulations might be broken. Still, a much smaller set of NIC drivers is needed than for real hardware. And of course networking is not essential for DOS. - VMs might have very limited PCI / PCIe simulation or a broken BIOS or a broken VGA / VESA (hardware/BIOS) simulation. Still, DOS should easily fall back to eg IDE PIO mode with plain classic VGA modes, why not? - IDE / SATA sim might have mediocre quality, see above (some other mails suggest that enabling more virtual PCI hardware in some VM makes UIDE a lot more happy?) - VMs might do stupid things with UMB space, but once you skip loading EMS/UMB drivers it should not matter and you can even have VM detection in JEMM386 itself. - VMs, unless "once meant for DOS", are unlikely to provide any decent virtual SoundBlaster16, but if they do AC97 / HDA, at least MPXPLAY has a chance. Which other things did I forget? As far as I can tell, all VMs will at least implement int 10, 13 and 16, as even newest Windows and Linux hopefully still rely on those for driver-independent user and disk I/O inside their boot loaders and boot menu. And as far as I can remember (see my "BIOS ... going away" mail recently) that should be pretty much enough for a basic FreeDOS. What other potential issues with virtual computers did I forget? Which systems have people tried so far? Qemu, Bochs, VMWare, VirtualBox, VirtualPC, maybe something Hypervisor like Xen with a bit of BIOS support added? Regards, Eric >> I believe it is a VirtualBox bug. > VirtualPC and VirtualBox seem to have their issues. Other emulators show > their own explicit nuisances as well ofcourse, but that seems to be more > limited. >> Oh well, I may have to switch my testing over to VMWare as I've never >> had these weird issues with it. I can upload my disk image and ova >> file if anyone else wants to do further research. > QEMU should be a good opensource solution I'd guess? Lots of features, > monitoring and logging. I like my VMware graphical frontend so sticking > to that. > Using as many different emulators/virtualisers as possible among > developers/testers might show issues earlier :) ... ------------------------------------------------------------------------------ uberSVN's rich system and user administration capabilities and model configuration take the hassle out of deploying and managing Subversion and the tools developers use with it. Learn more about uberSVN and get a free download at: http://p.sf.net/sfu/wandisco-dev2dev _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
