Pentax PocketJet 3 - Manual (Page 32)

Serial Menu:
If your printer is enabled with a serial port connection, you may
use this menu entry to set the parameters for your printer’s
serial port.
The printer is configured for 8 data bits and one stop bit. Baud
rate, parity and flow control may be configured here.
Baud rates of between 1200 and 115,200 per second may be
selected.
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