You toggle the switches to make the binary pattern you want at a specific location in RAM, then hit another button to store it. Repeat until the bootstrap is in RAM, and then press start to run the program from that first address. Said start address is always some hardwired starting location.

And that's a LATE example. Earlier (programmable) systems had other mechanisms for hard-wired or manual input like this. Go back far enough and you have systems that are so fixed-function in nature that it's just wired to do one specific job.

[–] mkwt@lemmy.world 2 points 3 days ago

It was also common to have a single step mode, where the CPU advances one cycle per switch press. Very useful for debugging.

And you could frequently read out the contents of registers directly on rows of lights. This led to the trope of the blinky light computer in Star Trek (original series) and elsewhere. Because the lights would flash in various patterns when the computer was running, as the register contents changed. But in the single step mode you could interpret the values.

[–] squaresinger@lemmy.world 18 points 1 week ago (1 children)

Hole punch cards are an automated form of that. Punch the holes manually, feed the deck through an automated feeder.

It's a storage medium that you can write to by hand.

[–] MonkderVierte@lemmy.zip 3 points 1 week ago

Well, punching the computer instead of a bunch of cardboard has it's advantages.