Ah yes, the old school Apple printers. Wouldn't it be cool if they still made them? (Printers, not Imagewriters, though - too noisy and slow for me.)
As far as I know, all you need is the Imagewriter extension, which is installed by pretty much any version of the MacOS since I don't know when (probably system 7.0). If the Imagewriter icon doesn't already show up in the Chooser, look in the "Extensions (Disabled)" folder; if you can't find it there, just install it from your system disk.