SWTP PR-40 Printer Interface Schematics

Apple I - printer interface schematic

The above was the most commonly used schematic for connecting a printer. It allowed the user to switch between two outputs: to the video monitor, and to both the video monitor and the printer.

The below schematics functions as the prevous one, but adds a third switch setting for printing without sending output to the video monitor. This increased the data output speed to the printer.

Apple I - printer interface schematic 2