The 442 Audio Card (MH030, SA4, Pro Tools Audio Card) is the NuBus card used in the original Pro Tools system. It supports the 442 I/O or ProMaster 20 Interface.Output: 4 channels of phase synchronous 16 bit audio.DSP: 2 Motorola 56001 processors.Connector: SCSI2 (50 pin).NuBus power consumption: 9.55 watts.DSP Clock Speed: 32mHzCurrent Xilinx chip (U45): rev R03