Mac OS 9 Chooser: Selecting Local and Network Printers

In Mac OS 9, the Chooser desk accessory was the centralized utility responsible for managing device connections, playing a vital role in routing print jobs to both locally connected and networked printers. Operating prior to the modern print management systems found in macOS, the Chooser bridged the operating system's software drivers with the physical hardware. It enabled users to designate their active printer, browse AppleTalk network zones, and toggle background printing services across the entire system.

Accessing the Chooser was done directly via the Apple menu. Once opened, the interface was split into two primary panes: the left pane displayed installed printer drivers (extensions located in the system's Extensions folder), and the right pane dynamically adjusted to show available connection options based on the driver selected.

For local printers—typically connected via serial ports (Printer or Modem ports) or USB on later hardware—the Chooser served as a direct hardware port selector. When a user selected a local printer driver, such as an ImageWriter or StyleWriter, the right pane presented icons representing the physical ports. The user simply clicked the corresponding port to bind the driver to the physical connection, establishing it as the destination for all subsequent print commands.

For network printers, the Chooser functioned as a dynamic network browser via the AppleTalk networking protocol. When a network driver, such as the ubiquitous LaserWriter driver, was selected:

• The Chooser polled the network using the Name Binding Protocol (NBP) to identify active output devices.
• If the network was segmented into AppleTalk zones, a bottom-left pane appeared listing those zones; clicking a zone refreshed the right pane with the printers located inside that specific subnetwork.
• Users clicked on the desired network printer from the list to assign it as the active output device.

In addition to routing, the Chooser managed print behavior by offering an option to enable or disable "Background Printing." Turning this on allowed the PrintMonitor or Desktop PrintMonitor utility to spool print jobs in the background, freeing up applications more quickly during the printing process.

Because classic Mac OS lacked dynamic, per-document printer selection within standard print dialogs for much of its lifespan, whatever printer was highlighted and active in the Chooser became the default system-wide destination. Mac OS 9 represented the final evolution of this architecture before Apple transitioned to the Print Center and modern System Preferences framework in Mac OS X.