The Windows 98 VM

The original game runs in an emulated Windows 98 SE PC under QEMU, for dynamic analysis and to test the rebuilt executable. (src/zbtools/vm.py; automation goes through QMP with qemu.qmp.)

Layers

 win98.qcow2          throwaway overlay: what `vm run` boots; `vm reset` discards it
   └ win98-game.qcow2   QuickTime for Windows 2.1 and the game      (vm install-game)
       └ win98-base.qcow2   the Windows 98 SE install, read-only     (vm install)

• install drives an unattended Windows 98 SE setup from a customised boot floppy and MSBATCH.INF (product key from .env), then answers the logon prompt itself with a blank password. Closing the QEMU window or pressing Ctrl-C aborts and deletes the partial disk.
• install-game builds a "tools CD" (game_install.py) holding the QuickTime installer (with its options file named QT32B42.INI; see installer settings), the game's files and a filled-in Zoombi32.CFG, boots the VM, runs the installer and powers off.
• run boots the overlay with the game disc in D:. --exe PATH carries an executable on a floppy, copies it into the game's directory as REBUILT.EXE and starts it. --trace LOG has QEMU log the executable's code as it runs, filtered to its addresses, stopping at 500 MB or two minutes; uv run trace LOG names the functions from the build's map.
• reset deletes the overlay. screenshot saves a PNG of the screen (this is also how to capture images of the original game).

Things to know

• The game refuses to start while its global atom Zoombini exists, which a crash leaves behind. Reboot the VM before running again.
• screen.py recognises the logon prompt and idle desktop by their pixels, which is how automation knows when a step is finished.
• Rosetta 2 cannot run 16-bit code, so Wine can't replace the VM on Apple Silicon.