Test Running OS X 10.4 (Tiger PPC) and Mac OS9 Backwards Compatibility On PC With Qemu (Win11 64bit)

#OSX #PPC #QEMU

Backwards compatibility and with ability to run software for older systems doesn’t necessarily have to mean it holds back progress. It provides access to legacy software that can provide insights into how things were done previously. In IT things are happening so fast that before you know it we’ve lost touch with what came before, or for example we’re confronted with an old legacy bug/security issue that was introduced somewhere and has been inherited over.

I find this whole thing fascinating, also hardware FPGA emulation as I do think it’s a way of preserving but also in the future researching how things were done in the past and how to move forward. Programming the hardware directly in assembly for example, is a bit of a lost art. Practiced on the early computer systems but these days most things are written in a higher language. The ability to still do so within emulators be it software or FPGA is a necessity so we will be able and keep having the ability to dive in deep close to the hardware still – especially when very low level bugs/security issues crop up.

So this emulated Power Mac G4 as a test, to see how compatibility is even through some nested emulation. If emulation is perfect and the speeds reached within the emulated client nested emulation shouldn’t necessarily suffer apart from introducing lag/delays in responsiveness if overhead is small.

OS Host: Windows 11 Pro 64bit 21H2
CPU Host: Ryzen 9 3900X
RAM Host: 32Gb DDR4 3600Mhz

Qemu-system-ppc-screamer-fpu.exe (32-bit)
CPU Client: G4 900Mhz QEMU PPC
GPU Client: QEMU VGA
RAM Client: 2Gb
OS Client: OS X Tiger (10.4 PPC) on Virtual G4 provided by Qemu and
Mac OS9.22 within OS X as backwards compatibility layer

The speed of course suffers from these emulation layers in this example as emulating a PPC Mac full speed with all bells and whistles still is some way off. But compatibility wise it is getting there. I am quite amazed how the nested emulation actually worked out. I wasn’t surprised there were issues for the Power64 emulator gauging at what speed to run at when running C64 100% as it probably measures it in a way that is not provided properly within the emulated environment (yet) – be it a register or possibly timing refresh rates or simple looped sample calculations.

Fascinating stuff, to me. But it might not be for all. Rest assured, non emulation geek videos will continue to appear on this channel.

Thanks for watching – LactobacillusPrime

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