Hi Jerome,
The VirtualBox user manual has more than 1200 pages, so now we know that "defaults for something with DOS in the title" are not good enough, but we do not know whether something can be manually done to fix things: https://download.virtualbox.org/virtualbox/7.1.2/UserManual.pdf The user manual says Intel (or all x86-64?) host CPU must have SSE2 support, for example. The known limitations mention that numlock emulation, CPU frequency metric and memory ballooning are not available on macOS hosts yet. There are some known issues with ATAPI for OS/2 and probably for other guest operating systems. The changelog says TF flag handling for CPUID when Hyper-V is used changed in 7.1.0? For security reasons, AVX, AVX2, XSAVE, AESNI, and POPCNT are not available for the guest, as nested paging cannot be made available in a safe way. Maybe compressors need POPCNT? I would assume they could ask CPUID to be sure. Up to date microcode is recommended. VirtualBox on Mac hosts can only do minimal mode, which makes virtuality visible and lets the guest see TSC and APIC frequencies. On Linux, KVM, and on Windows, Hyper-V are available alternatives. "Certain rare guest operating systems like OS/2 make use of very esoteric processor instructions. For virtual machines that are configured to use such an operating system, hardware virtualization is enabled automatically." (but it needs to be enabled in the host BIOS as well) You can disable SSE4.x for the guest, see section 9.25? And you can tune speed, see 9.11.2 ;-) In the handbook example, the guest sees BIOS DMI info mentioning an Intel Pentium III CPU, by the way. Possible soundcards are Intel AC97, Intel HDA and SB16. Graphics: VGA for legacy OS, 2 styles of SVGA. Chipsets: PIIX3 or ICH9. ACPI and TPM can be enabled or disabled. CPU-wise, PAE, NX and nested VT-x/AMD-V can be configured. The PDF does not say much about DOS, but it mentions that HIMEM bundled with Win3 uses at most 64 MB of RAM, while Win3 itself handles 512 MB with QEMM and similar. With VBoxManage modifyvm uuid-or-vmname you can set the --cpu-profile=host or Intel 8086 or Intel 80286 or Intel 80386. There are many technical settings, such as --x86-pae=on or off, --x86-long-mode=on or off, --hwviertex=on or off, --triple-fault-reset=on or off, --apic=on or off, --large-pages=on or off etc. pp. Even firmware can be bios, efi, efi32 or efi64 ;-) Possible --vm-execution-engine=default, hm, hwvirt, nem, native-api, interpreter or recompiler. See sections 8.2 and 8.36 for all the crazy details. My theory is that your troubles might be specific to some aspect of the default settings, so manually selecting something else, such as 386 instead of host CPU being visible but restricted, might help? You can even configure what CPUID should answer, with --cpuid-portability-level=3 selecting some "one size fits most hosts" humble defaults subset.
UNZIP, P7ZIP and possibly other programs now immediately... crash... Simply running "p7zip /?” Or just an “unzip” will cause VirtualBox to stop the VM.
Do they use the same DOS extender? Can you try pre-loading another? Like DPMIONE or DOS32A if the default is CWSDPMI? Note that CWSDPMI may default to write swap files on disk.
When creating the VM I use the title “FreeDOS T2410”. VirtualBox automatically selects the machine type as DOS.
Sensible start, given how complex VirtualBox config can be.
I usually give it 128mb of RAM.
Have you tried for example 24mb? Regards, Eric _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
