Here 'test' is not printed out because of the semicolon. Clearly, if you just want to use a single small pattern like the one above it is probably easier to use UDG's so that it can be printed on the same line as normal text. This function switches the printer on or off, and returns the previous status. Note that the function does not affect the printer buffer. This function is especially useful if you use the printer in combination with a comms link.
Some printers also have a magnetic card reader built in.
Even if the swipe reader is not physically present, the printer does still have the commands for the reader available. When you open the printer, there is a small plug inside with 5 pins which is where the card reader is connected, and the slot for the cards can be opened by removing the plastic cover that is wedged inside. At the moment we don't know which pin is which. A value of 0 means the organiser will wait indefinitely until a good card read is made. A value of -1 will allow this wait to be interrupted by a keypress.