Cassette tape-based navigation system from 1971
jalopnik.com
jalopnik.com
- one cassette tape per route
- distance to next milestone encoded in the bleep length on the tape
- controller unit interprets the bleep length
- controller unit reads RPMs from the spinning cable that normally drives the odometer
- controller unit has a pluggable circuit board that contains the wheel specific odometer RPM to distance conversion
- controller unit starts/stops the cassette player at each milestone
Granted, it is impressive for it's time.
https://www.fastcompany.com/3047828/who-needs-gps-the-forgot...
https://news.ycombinator.com/item?id=13744825
https://en.wikipedia.org/wiki/Etak
(The Fast Company article is quite good, with interesting photos.)