Originally, yes, there was one¹. But three were used quite soon after.² ¹ https://www.computerhistory.org/revolution/input-output/14/350 https://www.computerhi

Originally, yes, there was one¹. But three were used quite soon after.² ¹ https://www.computerhistory.org/revolution/input-output/14/350 https://www.computerhistory.org/revolution/input-output/14/3... ² https://youtu.be/yJDv-zdhzMY https://youtu.be/yJDv-zdhzMY