Another advantage was that it was possible for (skilled) humans to read the contents by pulling the tape through their fingers while holding it up against the light. At IBM I worked with a couple of graybeards who could do this.
At one time in my life I spent many hours every week decoding MS1553 traffic. basically, 4 digit hex numbers.
after about 6 months i was able to subtract in hex. and add. in my head. without writing anything down.
some parameters where in 'BAMS' (look it up, it is cool). could look at 2 4 digit hex numbers and understand the magnitude of the angle differences without thinking about it.
today, i need a calculator for anything...