Rd-1 Secret Usb Port! What?

[RFH]

I was just looking through a pdf with RD-1 parts when I noticed part number 125, listed as a USB cap. Intrigued, I took out my camera and pried open the tiny plastic square benath the SD card slot. Lo & behold, there's the USB connector no one has mentioned before! Doesn't seem to work, though.
Has anyone else noticed this? And why did Epson install a USB port that doesn't work? Your thoughts?

 

[back alley]

future plans that never came to fruition?

 

[RobVinc]

Maybe there is either no USB-driver-IC or the functions are missing in the SW.

Maybe it is only used with a special firmware for servicing issues?

 

[RichC]

I understand it is used by Epson for diagnostics. Despite running the unofficial R-D1 website for years, until recently, I had no reports that anyone outside of Epson had managed to interface with the USB port.

 

[RFH]

Rich, I guess you would know. Thanks for weighing in, and for the good work on the RD-1 site.