US Patent 7268911 Printer with speaker to indicate print error conditions

A printer includes a speaker to indicate print error conditions. The speaker is driven by a speaker interface that is responsive to the printer's processor. The speaker interface includes a DMA FIFO circuit that responds to DMA mediated requests, initiated by the processor programming a dedicated channel of its DMA controller, to retrieve sound files stored in memory. A digital-to-analog converter and amplifier are provided to convert retrieved sound files to an analog signal suitable to drive the speaker.