Memory & Storage: Crash Course Computer Science #19

So we’ve talked about computer memory a couple times in this series, but what we haven’t talked about is storage. Data written to storage, like your hard drive, is a little different, because it will still be there even if the power goes out - this is known as non-volatile memory. Today we’re going to trace the history of these storage technologies from punch cards, delay line memory, core memory, magnetic tape, and magnetic drums, to floppy disks, hard disk drives, cds, and solid state drives. Initially, volatile memory, like RAM was much faster than these non-volatile storage memories, but that distinction is becoming less and less true today.

CORRECTION: AT 5:00 we say "around 9 kilobytes" when we should have said "kilobits".

Want to find Crash Course elsewhere on the internet?

[jamespilcher]

"you may recognise this as a save icon but these were once physical objects" OH COME ON! When did I become prehistoric?! :)

[olympiawa]

You know you're old when you hear a kid say, "oh you 3D printed the save icon" lol. Whoever was the first person to say that deserves a high five.

[AudioGardenSlave]

Insane how difficult the climb to modernity has been in all aspects.

[kelliefay]

Carrie, you talked about Floppy disks like they were fossils. I suddenly feel very very old.

[donaldbustell]

Re: SAGE program at 1:20 - I worked on ASUPT - Advanced Simulator for Undergraduate Pilot Training - which the US Air Force brought on line in 1973. It was the first flight simulator to have a computer generated visual display. The computers (there were three) had core memory, mag tapes, and a disk drive with a stack of nine interchangeable 12 inch metal plates. It was programmed on cards in a combination of FORTRAN and the dialect of assembly for that machine. I don't recall the exact number of cards in the total load, but I seem to remember it was more than the 63500 you quoted for SAGE.

For what it's worth, the research we did on that machine to find out the best way to use simulators for pilot training led directly to the simulators used by airlines today to train their pilots and run annual emergency procedure check rides (think practicing engine out landings).

[francoislacombe]

I learned to program in FORTRAN on punch cards. I think Fred Flintstone was attending the same school.

[donreyes]

That was the best, most witty and smart, patreon showtout I’ve ever heard! 😆

[jecelassumpcaojr]

"Unpunching a hole is hard", but far from impossible. My university was still using punch cards in 1980 (replaced with terminals the following year) and the lines for the punch machines would get silly near course deadlines. So I had a bag of holes collected from the punch machines (on days they weren't so busy), a razor and one reference card with all the characters punched in it. Adding a few holes and eliminating a few from a card could be done in a minute instead of waiting hours in line for a free machine.

[weldin]

Guys just remember that these crash course videos are intended for students, people who generally weren't around for floppy disks. They still probably know what a floppy disk is though. Of course you don't have to be watching these for test purposes. They're fun to watch on their own.

[jameswhitfield]

the last 8 columns of the punch card used to number the cards in order. So, if that breeze came a long the, card puncher could be used to sort them back into the right order. They did have some smarts back then. love your stuff.

[oslonorway]

Oh boy, back when you ask a coworker if they had a _"Floppy disk"_ or a _"Hard disk"_ .

[SamCridlin]

In the early 2000s I worked in a data center that made good money by using 2 tape drives to move cold storage reels to DAT.
I have lived through way too many memory formats. Your coasters look way too familiar! Carrie, great series and episode!

[ishbanyadav]

This is really helpful for Computer Science students!

[donniedarko]

Currently studying computer science. This blows my mind!

[FortyTwo]

CrashCourse ROCKS! Hope our videos will reach your quality someday :)

[brandonbodine]

Thanks for another great episode! The mix of history and technical detail is just wonderful. Keep them coming please.

[enjoythelife]

I felt so old when you tslked about floppy disk not existing anymore. I mean, It wasn't that long ago. I think I used them 12 years ago.

[kurichan]

5:56 "If you have that kind of money to drop, did you know that CrashCourse is on Patreon? Wink wink-"

*Stop. I'm laughing too much.*

[pinklady]

You are a great tutor, Carrie. Thanks for making this tutorial.

[HenleyBailey]

This series needs more views, really well put together.