A point of sale (POS) system includes primary and auxiliary printers powered by a shared power supply. A POS terminal includes the shared power supply, a user interface, and a host including a printer driver for dynamically generating primary print commands. A printer connection card connected to the POS terminal includes a Universal Serial Bus (USB) hub in communication with the host and having at least one USB connector powered by the shared power supply. The primary printer is connected to the USB hub for receiving power and the primary print commands through the USB hub from the POS terminal. An auxiliary printer has a power-only connection to the printer connection card, receiving independently generated auxiliary print commands from a separate host computer. A controller includes control logic for selectively blocking the primary print commands to the primary printer in response to the signal drawn by the auxiliary printer exceeding a threshold.