righto.com

8eBAG TIL that the F-22 Raptor took so long to develop, that the CPUs for its in flight computer had become obsolete by three generations by the time the first production jet flew in 1997, resulting in even further delays as a new flight computer had to be designed based on the PowerPC processor.
GAQL5 TIL: Non volatile memory onboard the Apollo spacecraft were made by manually weaving copper wires between magnetic cores, bit by bit. Software had to be perfect because any revisions to code were impossible
KOX9B TIL that it is theoretically possible to mine new Bitcoins by hand with pencil and paper. Technology is a little bit faster, though - about a quintillion times.