| LP_PBUSY | inverted busy input, active high |
| LP_PACK | unchanged acknowledge input, active low |
| LP_POUTPA | unchanged out-of-paper input, active high |
| LP_PSELECD | unchanged selected input, active high |
| LP_PERRORP | unchanged error input, active low |
Refer to your printer manual for the meaning of the signals. Note that undocumented bits may also be set, depending on your printer.