The earliest copy of the driver I could find is LaserWriter 3.0 off of the "Printer Installation Disk" with System 3/Finder 5. This version was released in 1986, likely alongside the LaserWriter Plus upgrade. Going by the manuals, it looks like the original disk was called "LaserWriter Installation Disk" and worked with System 2.0/Finder 4.1 (the first to support the HD20 back in 1985), presumably identifying as LaserWriter 1.0.
