Welcome to OpenBIOS v1.1 built on Dec 9 2021 08:00
Trying cd:,\\:tbxi...
MacOS: unable to find a usable NVRAM partition - using offset 0x1400
call-method get-key-map exception -21
and refuses to boot. I have my qemu.bat file set up like this:
I'd guess based on all that that your macos9.iso file is damaged in some way, or is not one that can boot in QEMU.
QEMU can boot from the universal Mac OS 9.1 CD, the universal Mac OS 9.2 CD, and pretty much any 9.2.1 or 9.2.2 CD. The only 9.0 CD it can boot from is the G4 Cube 9.0.4 install CD.
There is some redundancy in your command line for running Mac OS 9.2:
qemu-system-ppc-screamer-60hz-fpu.exe ^
-L pc-bios ^
-cpu "g4" ^ =====> This is default for the mac99 machine, so can be omitted
-M mac99,via=pmu ^
-m 512 ^
-hda macos9.img ^
-cdrom macos9.iso ^
-boot d ^
-g 800x600x32 ^
-device usb-kbd ^ ====> this is implied when using ,via=pmu so can be omitted
-device usb-mouse ====> this is implied when using ,via=pmu so can be omitted
However, when emulating 9.0.4 or 9.1 with sound, best to use -M mac99 without the ,via=pmu and with -cpu G3.
Qemu running 9.0.4 does not handle two usb devices. 9.0.4 requires Mac OS ROM version 5.6 or above. As said The Cube installer contains version 5.6