I was interested in personal computers and then I discovered pre-microprocessor computers. This has got some wild solutions like rod cell memory.

A physical circuit board represent a record of database entry. To program the database one would wrap a copper wire around a rod. The rod would represent a field in a record of the database.

I think.

https://www.computerhistory.org/revolution/memory-storage/8/...

https://www.computerhistory.org/revolution/memory-storage/8/...