Re: [Qemu-devel] Old DOS under Qemu

[<jeebs@yango.us>]

Hetz;

Thanks for checking into this.


>partitions, format and boot the system) at http://bootdisk.com

I know that place well...  I've downloaded all of the boot disks from there 
and a few other places.

>All of the above OS's recognized the hard disk (although DOS 3.3
>recognized 32MB of it, if I'm not mistaken). I used the fdisk version

Right.  Back then, 32meg disk was considered more than enough by Microsoft.

(Of course, I can't really say too much... my first microcomputer didn't 
have a hard drive or even a floppy.  I used audio tape. for storage.)

>Mind you, I haven't really played inside (no himem.sys, no

I haven't done anything fancy either.

So you didn't need the -hdachs param.  I wasn't sure if I was going to or 
not, since the docs talk about it being for old dos.

>If you want, I can send you a bootable hard drive image with only the

That's alright.

I'm more concerned about testing qemu than actually running  old versions of 
DOS.

If I can get an old copy of DOS working, I may try Windows 1.0x and 2.03


>From unknown sources, I have Dos 3.2, Dos 3.3, Dos 3.3r, Dos 4.01, IBM Dos 
3.30, Dell Dos 3.30

I fully admit these are warez stuff of unknown quality.

However, I'm not getting the same results in qemu as I am with Bochs.

Dos 3.2
Qemu: Format failure. Bad partition.  If already formatted, it boots C:
Bochs: Same as qemu

Dos 3.3
Qemu: Format hangs.  If already formatted, Boot C: fails.
Bochs: Format hangs.  If already formatted, it will boot from C:

Dos 3.3r
Qemu: Fails to boot floppy.  Hangs.
Bochs: Same as qemu

Dos 4.01
Qemu: While booting from floppy, it causes Qemu itself to fail.
Bochs: Boots floppy.  Installs.  Fails to run from C:  Bochs gives an guest 
error message.

IBMDos 3.30
Qemu: Not bootable floppy.  Wont install.
Bochs: Not a bootably floppy.  (Didn't try installing it...)

Dell Dos 3.30
Qemu: Installs.  Wont boot from C:
Bochs: Installs fine.  Boots fine.


In three seperate cases, qemu is behaving differently from bochs.  And in 
once case it's aborting.

In no case does qemu manage to work with these images.  Even with warez 
stuff, I would have expected at least one to be not too badly broken or 
trojaned to be able to boot C:

So it's looking more like problems with qemu some how.  Frankly, I expect 
Boch's is much more accurate an emulation than qemu is!

I guess these aren't the biggest problem that Qemu has, but like I said 
previously, there aren't too many windows users in here, so I've been making 
a point to test about every OS I can find, along with watching for other 
Windows oriented problems.

Anyway, thanks for doing some testing.  If nothing else it prompted me to do 
more testing (and this time write down my results!)