how did we make the first computer operating system if we didn’t have computers to make them on?
In: Technology
Very early computers didn’t have an OS. You’d just run a program directly. (Also applies to some later computers, for example game consoles through the mid-90’s typically ran games as programs directly from ROM cartridges.) So I’ll rephrase your question as “How do you get a program onto a computer if you don’t have any running program on that computer, or any other?”
Three main ways:
– (1) Toggle switches. A computer has memory unit and CPU, plus a bunch of connecting wires called “bus lines”. Build switches that let you manipulate the bus lines directly. The memory does what the bus lines tell it. Have a human operator switch off the CPU, then switch the bus lines to input your program. One bit at a time.
– (2) Hard wired. Instead of having a memory unit that can store anything you want, instead hard-wire its responses to all possible inputs (addresses), to represent the program you want it to run. For e.g. the Apollo guidance computer, some worker had to [weave wires by hand](http://www.righto.com/2019/07/software-woven-into-wire-core-rope-and.html).
– (3) Punch cards. Mechanical, or mechanical / electric hybrid, machines had been used to process punch cards for decades, most famously starting with the [1890 census](https://en.wikipedia.org/wiki/1890_United_States_Census#/media/File:1890_Census_Hollerith_Electrical_Counting_Machines_Sci_Amer.jpg).
Punch cards are particularly fascinating. Basically you have a piece of cardboard, and a machine with electrical wires that try to make contact through the cardboard. Based on which wires make contact, the electrical part of your device “knows” if there’s a hole at a specific spot. Put maybe 100 or so spots on a cardboard. Then you can build specialized tools or simple mechanical machines to help people punch meaningful patterns on the cards efficiently.
Make feeder / hopper mechanisms to support working with large decks of cards. It’s an electronically accessible mass storage medium, that was already decades-old mature technology by the time the first computers came on the scene. If you were inventing one of the first computers, you could simply *buy* a typewriter that converted keystrokes into hole patterns on punch cards.
The Operating System didn’t just suddenly appear out of nothing, there were many steps between the first computer and the modern operating system.
The first computers did only one thing. The math people just connected wires and vacuum tubes to do the logical operations they wanted it to do. They weren’t very complicated by modern standards, a human could do it by hand. If you wanted the computer to do something else, you had to rebuild the entire thing.
Next they made it easier to do something different, by making it so you could just unplug and re plug the wires instead of building the whole thing. They also put together some bits that a lot of different math people were constantly doing, and just let you plug the wires into those.
Next they made it so that rather than plugging in wires, the wires were all connected to switches you go flip on and off. Because that was easier.
Next they made a machine that flipped those switches for you. They stored which switches to flip on punch cards and just put them into the machine. You can make the argument that this was the first operating system, though most people in the know would disagree with you.
Then a bunch of people wanted to use the same computer with their pile of punch cards. So they started writing down when they could use their cards. They’d hand it off to somebody to load all their cards for them.
Everyone then got sick of waiting for that guy, so they made a machine that figured out who gets to run their cards next and loaded the cards for them. This is probably where most people agree the operating system started.
Computers came before operating systems. The earliest ones simply ran programs that were physically wired into ROM by hand.
The first computers took instructions via [punch cards](https://en.m.wikipedia.org/wiki/Punched_card). So you’d literally load a huge stack of cards into the system and it would read the code.
Once it was in memory you could write that out to tape, and then subsequent machines would load the operating system from tape into memory.
Computers do not require an operating system.
An operating system allows for a lot of benefits, namely you can have multiple tasks run on the same computer. But there is no absolute need for an operating system, most early computers in fact ran without them, each person wanting to use one was allocated a time slot when their program could run, back when programs were programmed with punchcards.
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