[Qemu-devel] Running Windows on OSX : a few notes

[Laurent Amon]

I've been playing with running Windows 95 and 98 on my TiBook 400, using QEMU
CVS of 3 days ago with my keyboard patch. Here are a few notes:
VIDEO :

In terms of performance, W95 feels faster that W98, but not that much. Since 95
lacks in some functionalities, I'll go with 98 anyway. The best way to get
performance is running in 16-bit color mode with host in 16-bit color, in
windowed mode.

Speaking of the video, the full screen mode is painful because every time there
is a video mode change, SDL does a fade-to-black followed by a fade in and this
takes forever. The solution is to patch SDL to comment out the calls to the
fading effect. In addition, the way it works, QEMU calls the routine twice
where I think we could do with once (and actually, when running with 2 screens,
it does it 4 times!).

When going out of full-screen mode, if the window is partially off screen, QEMU
will crash (with SDL 1.2.7, binaries downloaded from the site).

CDROM :

It is possible to access a physical CDROM from Windows guest. You just need to
unmount (without ejecting) the media first : disktool -u disk1 for example and
access /dev/disk1s0.

Unfortunately, the cdrom is recognized as an audio CD with 1 track per
session... Not exactly what you want. I'm out of my depth here, so I haven't
even looked further.

Keyboard :

The patch(es) I posted these 2 last days enable you to better use the apple
keyboard. It is not perfect yet, but I'll look further. I may need to create a
keyboard mapping inside of Windows to reaffect the different arrangement of
some characters (not keys).

I'd also like to be able to map the command keys to a Windows key to in effect
get a 104-key keyboard.

Benchmarks :

Win95 reboots in 90 seconds. Win 98 in 110 sec in windowed mode. I9n fullscreen,
the fade out effect takes so much time that I didn't even bother.

Using FreshDiagnose (which crashed a lot, but I coudn't hunt an old version of
Sandra to try on my Win95), Win95 reports the proc as 25 MHz, an Win98 as 50
MHz. The Whetstone is 2 vs 4. It feels like a 25 MH anyway.

Disk access is of the order of 3.5 MB/s writing, 2.5 MB/s reading for Win98 on
FAT32 system. Strangely, reading speed drops to 1.75 MB/s on FAT16. Win95 is
faster reading (3.5 MB/s) and slower writing (1.5 MB/s)

I have had enough problems running the bench that I'd like independant
confirmation of these results.

Video benchmarking failed on Win95 and gave few differences between windowed
mode and fullscreen on Win98 :
Random pixels : 33 000/s
Lines : 2600/s windowed, 2333 fullscreen
Text : 6000/s
Circles : 140/s


That's all for now,

Lga.