Run Tiger, Leopard, or any Mac OS X PowerPC version on M1

Demo environment: macOS 11 Big Sur host running on Apple silicon, Mac OS X 10.4 Tiger guest.

Setup & Install

Create a new virtual machine in UTM with settings along these lines:

System:
- Architecture: PowerPC
- System: Mac99
- Memory: 2048MB
- Advanced Settings:
  - CPU Cores: 1
  - enable Force Multicore
Drives:
- create 1 new 20GB IDE
- 1 imported drive (your OS X PPC ISO); change Image Type to "CD/DVD (ISO) Image" and move to top of list
Display:
- Emulated Display Card: VGA
Network:
- Network Mode: Emulated VLAN (to enable port forwarding - see "File & Screen Sharing" below)
- Emulated Network Card: sungem

Install Mac OS X. Shut down and change drive order in VM settings, moving 20GB IDE to top of list. Reboot and set Startup Disk in System Preferences.

The result is surprisingly performant. But we can speed things up a bit more:

Optimize

Change the Dock from 3D to 2D:

defaults write com.apple.dock no-glass -boolean YES; killall Dock
Disable Dashboard:

defaults write com.apple.dashboard mcx-disabled -boolean YES; killall Dock
Disable Spotlight and hide its icon:
1. Open /etc/hostconfig and change "SPOTLIGHT=-YES-" to "SPOTLIGHT=-NO-"
2. mdutil -i off /
3. mdutil -E /
4. sudo chmod 600 /System/Library/CoreServices/Search.bundle/Contents/MacOS/Search && killall SystemUIServer
System Preferences:
- Desktop & Screen Saver → Desktop → Solid Colors → click desired color
- Desktop & Screen Saver → Screen Saver → Start screen saver: Never
- Displays → Display → Colors: Thousands
- Dock → uncheck "Animate opening applications"
- Sounds → Sound Effects → uncheck "Play user interface sound effects"
Finder: Preferences → uncheck "Spring-loaded folders and windows"

File & Screen Sharing

AFP

VM settings: Network → Port Forward → New → Protocol: TCP, Guest Port: 548, Host Port: 54854
Guest: Enable Personal File Sharing in Sharing preference pane
Host: Finder → Go → Connect to Server → afp://127.0.0.1:54854 → Connect

VNC

VM settings: Network → Port Forward → New → Protocol: TCP, Guest Port: 5900, Host Port: 59000
Guest: Enable Apple Remote Desktop in Sharing preference pane
Host: /System/Library/CoreServices/Applications/Screen Sharing.app → Connect To: 127.0.0.1:59000 → Connect

SSH

VM settings: Network → Port Forward → New → Protocol: TCP, Guest Port: 22, Host Port: 22222
Guest: Enable Remote Login in Sharing preference pane
Host:
1. Create or edit ~/.ssh/config, adding these 2 lines:
  Host localhost KexAlgorithms +diffie-hellman-group1-sha1
2. CLI: ssh -p 22222 localhost
3. GUI: There are a number of SFTP options, including Forklift: Go → Connect → Server: localhost, Port: 22222, specify username and password → Connect

Notes

Initially received "No valid state has been set by load or init-program" error when booting from OS X 10.4 ISO. Re-ripped Tiger DVD this way to resolve:
1. Disk Utility → select DVD drive (not "Mac OS X Install DVD") → File → New Image → "Image from DVD drive name"
2. Save As: Tiger (.cdr will be appended automatically during imaging, superseding any other specified extension (like ISO)) → Format: DVD/CD master → Save
3. When imaging is complete, select Tiger.cdr in Finder → File → Get Info → check box next to "Locked"
To capture mouse or keyboard input (especially for Command key shortcuts, which the host often interprets instead), click the cursor icon in the toolbar or use Ctrl+Opt (can be changed to Cmd+Opt in UTM's preferences).
Software Update in Tiger still works! The updates were presented in the following order:
- First round:
  - Java 1.3.1 and 1.4.2 Release 2 | Version: 2.0
  - Mac OS X Update Combined (PowerPC) | Version: 10.4.11
- Second round:
  - X11 Update 2006 | Version: 1.1.3
  - Migration and DVD/CD Sharing Update | Version: 1.1
  - QuickTime | Version: 7.6.4
  - Security Update 2009-005 (PowerPC) | Version: 1.0
- Third round:
  - J2SE 5.0 Release 4 | Version: 4.0
  - Safari | Version: 4.1.3
- Fourth through Eighth rounds: Java updates, one per round:
UTM/QEMU also offers x86/x64 emulation (allowing the use of Intel-only OSes like Windows XP, OS X Mavericks 10.9, etc):
- Emulating Windows XP x86 under M1 Mac via UTM & QEMU
- Virtualizing OpenCore and x86 macOS on Apple Silicon (and even iOS!)
- utmconfigs: Config files for booting x86 OS X on UTM emulator (very useful for finding compatible settings; e.g., Mavericks networking had to be changed to "Emulated VLAN" and "usb-net")

Sources

Pixlet's comment on MacRumors
Mac OS 9 Emulation On My Apple M1 Mac Mini (UTM)
Access your UTM VM over ssh
Solution for SSH Unable to Negotiate Errors (which credits How to enable diffie-hellman-group1-sha1 key exchange on Debian 8.0? which in turn credits OpenSSH Legacy Options).

MacWorld: Can M1 Macs run older versions of macOS? "Need to run Catalina, Mojave or an older version of macOS on an M1 Mac? Here's why you can't..." ;-)
Running Mac OS 9 and Mac OS X 10.0 - 10.4 on Apple Silicon (M1) & Intel via QEMU
Running Mac OS X as a QEMU/KVM Guest
QEMU: Documentation/Platforms/PowerPC
Fast UTM shared directories using Samba
Virtualizing Linux, macOS, and Windows ARM64 versions on an M1 Mac
QEMU PowerPC G4 OS X Tiger (10.4) setup
A beta PowerPC version of Snow Leopard exists:
as well as an optimized version of Leopard for PowerPC:
- Mac OS X Sorbet Leopard: "The world's most advanced operating system for PowerPC Macs. Finely tuned."
- Sorbet Leopard - 10.5 Reinvigorated
- There's a CHILLING New OS X For PowerPC Macs!
AFP:
- Apple Filing Protocol
- TCP and UDP ports used by Apple software products
- If you’re using AFP to share a Mac drive, It’s time to change
- Can you still use AFP sharing?
- Tunneling afp over ssh
- Establishing an SSH Tunnel to Remotely Access a Mac Using AFP and VNC
- No AFP in Big Sur: "Actually it's still possible to connect to AFP shares (I just tried it and it works)."
- Can I still use Apple Filing Protocol (AFP) in Big Sur: "Big Sur no longer supports sharing volumes via AFP, but it can still access AFP shares from other machines."
- AFP file sharing on macOS Big Sur (how-to)

created: 2021.11.22, updated: 2023.02.19