RRD50 interface

Sorry for the mis-threading, I lost the original posting. The older CDROM drives were in fact CD audio drives with the logic bolted on in place of the serial DACs. In fact I used to have an old Reference Technology drive which was a commercial CD drive and several boards worth of discrete logic which performed the C3 ECC correction. The CDROM functionality was just connected in place of the DACs. I suspect the RRD50 interface is three main wires: Bit clock (32x data rate) Left/Right (high for left, low for right, or vice versa) Serial data And, if memory serves it was called an I2S interface, though what the acronym stands for I don't recall. Unfortunately, I don't have any documentation of the parts I worked on for Cirrus Logic from the early CDROM projects. Those drives were based on a CD audio DSP chip (analog, servo, laser control, C1 & C2 ECC) and a backend chip (C3 ECC, cache memory, and ATA interface). Sony was the primary supplier of the DSP chips and Cirrus, Oak Technology, and a few others made the backend chips. A perusal of the CD documents (Red book) and CDROM document (Yellow book) might sheds some light on it all. Clint