The Central Processing Unit (CPU): Crash Course Computer Science #7

The Central Processing Unit (CPU): Crash Course Computer Science #7

Take the 2017 PBS Digital Studios Survey: http://surveymonkey.com/r/pbsds2017. Today we’re going to build the ticking heart of every computer – the Central Processing Unit or CPU. The CPU’s job is to execute the programs we know and love – you know like GTA V, Slack… and Power Point. To make our CPU we’ll bring in our ALU and RAM we made in the previous two episodes and then with the help of Carrie Anne’s wonderful dictation (slowly) step through some clock cycles. WARNING: this is probably the most complicated episode in this series, we watched this a few times over ourselves, but don’t worry at about .03Hz we think you can keep up.

Produced in collaboration with PBS Digital Studios: http://youtube.com/pbsdigitalstudios

The Latest from PBS Digital Studios: https://www.youtube.com/playlist?list=PL1mtdjDVOoOqJzeaJAV15Tq0tZ1vKj7ZV

We’ve got merch!
CrashCourse

Want to know more about Carrie Anne?
https://about.me/carrieannephilbin

Want to find Crash Course elsewhere on the internet?
Facebook – http://www.facebook.com/YouTubeCrashC…
Twitter – http://www.twitter.com/TheCrashCourse
Tumblr – http://thecrashcourse.tumblr.com
Support Crash Course on Patreon: http://patreon.com/crashcourse
CC Kids: http://www.youtube.com/crashcoursekids

Want to find Crash Course elsewhere on the internet?
Facebook – http://www.facebook.com/YouTubeCrashC…
Twitter – http://www.twitter.com/TheCrashCourse
Tumblr – http://thecrashcourse.tumblr.com
Support Crash Course on Patreon: http://patreon.com/crashcourse

CC Kids: http://www.youtube.com/crashcoursekids

50 Comments

  1. oussama jaballah on November 9, 2019 at 5:55 pm

    This video answered all the questions I had for years in less than 12 minutes ,It’s just an unbelievable work . GJ Crash Course, You guys just changed my life.



  2. JMS on November 9, 2019 at 5:58 pm

    I’m curious why this video takes the time to define what 1Hz is, but assumes that I remembered/comprehended logic gates from the last episode.



  3. Amanda Purello on November 9, 2019 at 5:58 pm

    a very good explanation



  4. Jared Miller on November 9, 2019 at 6:00 pm

    What?



  5. Vaibhav Arora on November 9, 2019 at 6:00 pm

    Marry me Carrie



  6. Hombre Pobre on November 9, 2019 at 6:01 pm

    i can’t find #8 tutorial



  7. Milosh Flanders on November 9, 2019 at 6:03 pm

    Omg! I am an embedded systems/firmware engineer and I am learning A LOT with ths course! Best course ever



  8. Robin Li on November 9, 2019 at 6:03 pm

    I was staring at the creeper in the background the entire time



  9. wildfyah on November 9, 2019 at 6:06 pm

    This helps a lot. Thx



  10. Dadou on November 9, 2019 at 6:07 pm

    Very nice video thanks ! Would be awesome if you spoke a bit slower and make the video longer



  11. Deejay Tiesto on November 9, 2019 at 6:07 pm

    you’r awesome



  12. akash kadambi on November 9, 2019 at 6:09 pm

    @2:54 how it gets copied into instruction register pls tell in detail I’m dying out of confusion…pls respond…



  13. Gaming Cookie on November 9, 2019 at 6:12 pm

    How many levels of abstraction are we at by this point?



  14. Artemee Senin on November 9, 2019 at 6:13 pm

    This is absolutely great! Thank you a lot for this amazing work! 🙂



  15. Santiago Morales on November 9, 2019 at 6:14 pm

    the spanish translations is wrong when it gets to the intel 7007 (aprox 9:25) cause it says "740" instead of "740000"



  16. promethful on November 9, 2019 at 6:14 pm

    "…but there isn’t a miniature Carrie Anne inside every computer…"
    Only in some computers then?



  17. Ti m on November 9, 2019 at 6:15 pm

    Your abstraction joke is pretty overused. But why no Battle Phase II ?



  18. Bobby Digital on November 9, 2019 at 6:17 pm

    I love your enthusiasm and the editing is really good, prob the best ive seen.



  19. Pickle Jar on November 9, 2019 at 6:18 pm

    Hey I’ve got a question, how do input electric signals start in the hardware? Like if I have a code that says Load_A, how does this create an electric signal for the instruction address register to then start?

    Thanks anyone who can help!



  20. mcgames on November 9, 2019 at 6:18 pm

    This is the Scott cpu?



  21. Jude & Leah Productions on November 9, 2019 at 6:19 pm

    Another level of abstraction af tbh



  22. Ran Van Loon on November 9, 2019 at 6:20 pm

    Stop trying to make fetch happen Carrie Anne, it’s not going to happen!



  23. Haipeng Li on November 9, 2019 at 6:21 pm

    Is it only me that thinks she’s speaking too fast for a crash course?



  24. Harris on November 9, 2019 at 6:22 pm

    There’s also something called the CPU Cache, which acts much like RAM and the control unit’s memory. It’s basically memory that is tied in directly with the CPU, and is much faster than the RAM, but only contains 1 or 2 megabytes of memory.



  25. Finlay Kolijn on November 9, 2019 at 6:24 pm

    Creeper…



  26. 석영미 on November 9, 2019 at 6:24 pm

    That moment you thought you understand but then no



  27. Zany Dustman on November 9, 2019 at 6:25 pm

    0.03 Hertz is about 10 cycles in 6 minutes…



  28. Ballista on November 9, 2019 at 6:26 pm

    GREAT! You and the whole team are awesome ! 🙂



  29. Mohammed Alassaf on November 9, 2019 at 6:27 pm

    help



  30. Ân Trần Cao Bảo on November 9, 2019 at 6:27 pm

    I learnt about this at school and professor told us to build this one using Verilog HDL, but I coundnt do that :))



  31. Yeti97 on November 9, 2019 at 6:28 pm

    LORD I WILL UNDERSTAND THIS NO MATTER HOW MANY TIMES I HAVE TO CLICK THAT REPLAY BUTTON



  32. JakkuWolf Insomnia on November 9, 2019 at 6:29 pm

    I love it, it’s actually simpler than I initially thought it was. It’s very basic crude machine language programming



  33. christian37ism on November 9, 2019 at 6:30 pm

    This video brought all the conglomerate parts of a cpu + ram seamlessly together. It was a bit of a review for me but extremely well packaged into one video. And I’m also glad you mentioned the negative drawbacks of overclocking, and the advantages to under-clocking. Thanks



  34. toothless nightfury on November 9, 2019 at 6:31 pm

    but yet you did not explain what do you mean by "Data", input data , store data, we know there isn’t a magic beam ray going throw these circuits but electricity, so data? what is it a fixed current of electricity? what is it.



  35. Kartik K Srivastava on November 9, 2019 at 6:32 pm

    Thank u very much



  36. Master Lavellan on November 9, 2019 at 6:33 pm

    This is so beautifully visualised!



  37. docteurgreene on November 9, 2019 at 6:38 pm

    9:37 this is my CPU ! lol



  38. KnightSteel on November 9, 2019 at 6:39 pm

    How does the program counter get incremented? Is there a separate adder circuit just for the program counter or does it get incremented by the cpu?



  39. HAILSTONE AERIAL FILMS on November 9, 2019 at 6:40 pm

    Brain has preformed an illegal operation as must shut down



  40. crazy pancake on November 9, 2019 at 6:41 pm

    This is so cool! The way it added the values and read it into the RAM is a neat process that we can appreciate.



  41. 이주연 on November 9, 2019 at 6:41 pm

    Emotional control is by the brain, not the heart!



  42. Hans Byager on November 9, 2019 at 6:42 pm

    You are Awsome, im studying this at the moment, and the book is utter nonsence written down on paper, but you make it so easy to understand! thank you SO much!



  43. A I on November 9, 2019 at 6:44 pm

    These went from explaining, to executing, without explaining what you’re executing. For example – What is “13”? What is “15”? What LEVEL of information are we talking about in the first half of this video? Turning on a program? Or just barely telling the on switch to wake up, for a program? We’re talking about what volume of real-world information? What amount of information is a “value” of information? Loving these videos overall, just wish for some perspective for those of us for whom this is still entirely new.



  44. Utilka on November 9, 2019 at 6:45 pm

    learning orgasm experiensed
    thanks
    a clear like

    haven’t liked any video in a few monthes for now
    damn you are so good



  45. Arun Kumar on November 9, 2019 at 6:47 pm

    There was once a new little restaurant opened by a highly motivated fledgeling chef near the place I live and he made the most amazing sandwiches. I regret not visiting that place often and not promoting it enough, because soon the restaurant shut. (obviously due to multiple reasons and not my inaction). Well, since then I make it a point to comment/promote things I think are surely precious to the world. This video is one such. The effort to abstract is amazing. To those who’re finding it difficult, I only urge you to build some base and get here, and you’ll find this a dream! The presenter and her humour/script are brilliant!



  46. Anvesh Jhuboo on November 9, 2019 at 6:48 pm

    This is awesome!



  47. Steven Farabee on November 9, 2019 at 6:50 pm

    Where is nothing on the ground? A cpu. lol.



  48. Kainan Sugal on November 9, 2019 at 6:50 pm

    Very complicated, my brain is freezing it can’t handle this.



  49. Take Elite on November 9, 2019 at 6:51 pm

    maybe I lost something in the path but where the instruction table come from? Is it an arbitrary assignment or something "official" ?



  50. Ærinmund Fågelson on November 9, 2019 at 6:52 pm

    In this example, why is the instruction register taken from the RAM? Shouldn’t it be taken from some source code somewhere? Or is there something that writes the source code into RAM first of all?