GUS 4.11 driver in FreeDOS says it can't find the card

[Swap Jim]

I'm running qemu-w64-setup-20190815 under Windows 7. I created the HDD 
image using this command:

> qemu-img create -f raw freedos.img 20M
        
I installed FreeDOS 1.2 (latest stable) using this command:

> qemu-system-i386 -m 16 -rtc base=localtime -soundhw gus -device 
cirrus-vga -hda freedos.img -cdrom FD12CD.iso" -boot order=d

And then this one to run the VM:

> qemu-system-i386 -m 16 -rtc base=localtime -parallel none -hda 
freedos.img -boot order=c
        
Now, it's time to install audio drivers, so I downloaded the 
GUS411CD.ZIP from this link:

> https://gona.mactar.hu/GRAVIS/

and run INSTALL.EXE. The installer says:

> Cannot determine the UltraSound card type.
>
> This is usually caused by a base port conflict. You should exit 
INSTALL remove the UltraSound Card and run CONSCAN.EXE.

If I remove the card, the CONSCAN program says that ports 210-230 "do 
not not seem safe for synth base", but 240-260 "seem safe for a MAX, and 
base GUS". If I put back the card, the ranges change to 210-240 and 
250-250, respectively. So the card takes the 240 port, and we can see 
that from 'gus.c' [1]:

> DEFINE_PROP_UINT32 ("iobase",  GUSState, port,        0x240),

If anyone wants to test this, I've made a 20MB HDD image that contains a 
base FreeDOS installation and the audio driver. It's 10MB compressed:

> https://www.dropbox.com/s/syyu7fxux0el3bd/freedos.img.xz?dl=1
        
(This is a direct link, there is no intermediate web page requiring 
clicking on links, so, wget/curl will download the file.)

Any idea on what's happening and how to solve this?

[1] https://github.com/qemu/qemu/blob/master/hw/audio/gus.c