Tape has come a long way since the 800 BPI (bits per inch) NRZI (Non-return zero insert) and 6250 BPI PE (Phase encoded) 2400' tapes I worked with in the 70's.

Tape has come a long way since the 800 BPI (bits per inch) NRZI (Non-return zero insert) and 6250 BPI PE (Phase encoded) 2400' tapes I worked with in the 70's. The tape sort algorithm read tapes backwards to avoid the delay of rewinding. Pretty cool. If you put a ping pong ball atop the blast from the vacuum pumps, it would hover magically in the air. If a tape got worn out from use, you cut off the first 100' and pasted a new silver Load Point Marker.