I owned an old tape reader head from a puncher/reader machine that was scrapped in the early 1990s. I removed and held onto the reader head before the rest of the reader/puncher was trashed. It remained in my Kennedy machinist tool chest for years and along about 2011, I gave the reader head purpose and interfaced it with one of five PLC circuit boards I salvaged from junk machinery in 2003. I interfaced that reader w/PLC board to an MS-DOS laptop and began to write code.