How did old computers run without operating systems?

Question

The first operating systems were discovered in the 1950s. So how did older vacuum tube computers like Z3, Mark 1, ENIAC , EDVAC, etc work in the 1940s and earlier? There were said to be programmers and coaders from the 19th C, how was that done, how were bombs deployed in WW2 by computers. it is said that a computer is usless without its software, so how did the pre OS computers work and how were they programmable?

Answer 1

ENIAC might not even be considered a computer by our standards now. That device and possibly some of the others you mentioned did not store programs in memory. That detail would make it difficult to have program(s) that help someone manage the running of the machine. That is the essence of an operating system is a program or programs that help you manage the running of the machine.

ENIAC was programmed with patch cords, dials, and switches. Programming was very expensive, a program to help manage the running of the machine would have been considered too expensive, even if they had thought of it.

I think the Mark 1 was one of the earliest to store programs in memory. That innovation would have made writing programs to help manage the machine more practical. Even after it was possible, create these types of tools there was plenty of toggling machine code in manually.

Even as late as the 1970s I remember sitting in a computer lab toggling in a small machine language program into a PDP11 so it could read a paper tape that would load a programs that would let me edit, assemble, run, read, and punch assembly language programs.

Answer 2

The first operating systems were NOT "discovered"; they were and are the creations of men and women.

Please let me know if you need any further help with this question or any question involving American history or the history of science.