The pioformat formatter driver requires a print formatter to contain the following function routines:
| Item | Description | 
|---|---|
| initialize | Performs printer initialization. | 
| lineout | Formats a print line. | 
| passthru | Passes through the input data stream without modification or formats the input data stream without assistance from the formatter driver. | 
| restore | Restores the printer to its default state. | 
| setup | Performs setup processing for the print formatter. |