Re: [PATCH v2] x86/vm86: Remove deprecated VM86 support

[Jari Ruusu]

H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> Dosemu, perhaps, but Dosbox or KVM have no such constraints.
> Both are likely to perform better than dosemu on "modern"
> (< 20 years) old hardware.
 
I didn't know Dosbox existed. Thanks for letting me know about it.
 
Brian Gerst <brgerst@xxxxxxxxx> wrote:
> You can install FreeDOS from an ISO image[1] into a new virtual
> machine, just like you would install a Linux guest. You don't  
> need Dosemu. Performance should be no worse than your current  
> setup, since KVM can execute real mode code in hardware similar
> to VM86 mode.
> 
> [1] https://www.freedos.org/download/
 
I quickly looked into FreeDOS documentation, and it seems that
Qemu/KVM + FreeDOS combination is missing one crucially important
feature that dosemu + FreeDOS combination has: ability to create  
"network drive" from host directory tree, and ability to do that
without any network or network protocol drivers consuming
resources from DOS's precious little 640 KB RAM.
 
I am aware of, and I have tested Qemu's "-hdb fat:/my_directory"  
option. It creates a temporary FAT file system image file which is
not a "network drive", and as such, DOS won't see files added to
or removed from that directory tree while Qemu is running.

--
Jari Ruusu  4096R/8132F189 12D6 4C3A DCDA 0AA4 27BD  ACDF F073 3C80 8132 F189