On a specific PowerBook (1.5GHz, adb keyboard, ATI graphics), vt crashes very early in boot, before printing even the `KDB:...' lines, unless we break into Open Firmware at boot, and boot the loader using the `mac-boot' command. Removing vt and using sc instead works just fine. This is an anomaly, as on 3 other PowerBooks of different generations from this one work just fine with vt(4).