More detail to earlier post. https://www.vintagecomputer.net/FANUC/ Reader Part number A860-0056-T020 http://vintagecomputer.net/FANUC/FANUC%20A20B-0004_pwr-connect1.jpg http://vintagecomputer.net/FANUC/FANUC%20A20B-0004_250WV-AC-cap.jpg Here is the control board on the reader which has 50-pin tape in and punch out ports: http://vintagecomputer.net/FANUC/FANUC%20A20B-0004_IO-board.jpg http://vintagecomputer.net/FANUC/DOSTEK-440a-BTR.jpg The 50pin rainbow cable coming off the punch port is connected to a behind the tape reader (or "BTR"). The BTR converts the signals and sends them to a computer's serial port so they can be captured into a tape image. This is what they made when indudstrial processes converted from using actual tape readers and tapes to saved tape images. The BTR was the gateway between the reader and a computer. This FANUC 6 hardware manual, which includes this model of tape reader as part of a larger system, references the part numbers found on the reader, which is how I learned what I learned about it. http://cncmanual.com/download/1646/ I am working to safely power it up. Not in a rush to fry it.