Submitting software upgrades to a digital printer through a standard port

摘要

A system for submitting upgrades to software which operates a digital printer. The software enters the printer through a standard printer port. When an upgrade is sent, the status pins are reassigned new functions relating to the progress of the software upgrade, instead of using the status pins of the printer port in a standard fashion for submitting print data. In upgrade mode, the levels of the status pins are recognized as a multi-bit word, relating to a specific condition of the upgrade.