4. IBM Vacuum Column Tape Drive

Beautiful and very heavy technology from IBM in the 1960s.  Huge power demand but amazing high speed sequential access of the tape.

As a kid, I was lucky to spend a couple of weeks in Unilever at Circular Quay, in the computer department, which had these and also some NCR mainframe.  Dozens of punch card operators on the floor and all the accounting done by computers. Later in the 1970s I was trained in electronics with the Airforce to learn a lot of this equipment.
In stark contrast to these beasts, the modern Intel 8080 and Motorola 6800, both 8 bit computer CPUs were faster in processing than the big IBMs of the 1960s. Both these new generation CPUs were born in 1974 and I was learning them from 1977.
The IBM system in this video has a Central Processing Unit running at 90kHz. The Motorola 6800 was clocked at 1MHz and the 8080 at a staggering 2MHz!