How your computer's memory works

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Huge thanks to my supporters on Patreon: Dan Hanvey, David Efird, Suzanna Hofman, Amy Hadden, Ethan Fuller, Charles Bray, Syafiq Kay, Xavier Chesterfield, Jay Wright, Myles Kornfeld, Louis Gillet, Michael Phillips, Fraser Birks, Martin Hermes, Luca Schumann, Rhys Rickard-Frost, Cameron Matchett, Lachlan Woods, Tim Boxall, Simon Vaes, Gabriele Mozzicato, Jawad Alalasi, Gaia Frazao Nery, Kodzo, Claire Anthony, Eve Dillon, Rowan Gow, Matthias Loos, James Bridges, James Craig, Angela, Sanaa Al Derei, Mark Anthony Magro, Liam, Theresa Wang, Wendover Productions, Kendra Johnson, Caitlin Louise, Daniel Blume Høj, Hayley Ward.

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[timbanks]

One slight correction Simon. The BABY instruction code is bits 1-5 (only) that describe the program line to which the instruction - bits 13, 14 and 15 - operate on. Bits 6-12 are unused as are bits 16-32 - EXCEPT of course for a number which uses all 32 bits on a line (as you quite correctly explained). You only need 5 bits to address all 32 lines in the memory. One other point of clarification, any line in the store can contain an instruction OR a number. The program in memory in your video only used the upper store lines for instructions, but some programs put instructions and data in other areas of the store. Cheers - Tim the BABY volunteer

[mondstaubfee]

The structure of your videos really helps understanding what you want to teach. Also the videos about more advanced topics (and the vlogs) are so well produced and interesting, I wish you would have more viewers who appreciate your work. I'm so glad I found your channel a while ago. Keep up your great work! :) (Greetings from Germany!)

[thesecretorganist]

I have genuinely always wanted to learn about this. Thanks!

[erikc]

4, 294, 967, 295 is the largest number a 32 bit computer COULD store, but it depends on the architecture of the computer. Specifically it depends on whether or not the computer needs to able to deal with negative numbers.
The way this is done is with signed number representations, basically you use a bit to store if a number is positive or negative. The Manchester Baby uses "Two's complement" signing, which means possible values it can reason about is −2^31 to +(2^31) − 1 or -2, 147, 483, 648 to 2, 147, 483, 647. (The reason we subtract a one from the positive side is because 2^31 gives us the amount of numbers we can represent and we need to represent 0, but we need only to do that once).

[claudiajade]

Well...I am looking at my little super laptop with new appreciation. Also, My God we have come a long way in 70 years. Really puts in perspective

[girv]

Ben Eater’s channel is amazing btw. If you want to get at the nuts and bolts of how computers work then it’s a great resource.

[matthewfound]

I've succeeded in life, finally I know more about a topic than Simon!

[Simone-uune]

I'm a computer science student, I already know these kinds of things (applied to other CPUs), but I can't stop watching this video! I'm in love with your accent and with your curiosity, which is really important in the science's world.

[KentonKwok]

Love how you're going into different fields! Intellectually stimulating!

[shamr]

Very cool video dude. Looking forward to more stuff like what you've been making lately.

[kenmken]

This is a really in depth video with a lot of unique insight. Kudos.

[jamesjohnson]

Recently discovered your channel Simon. All I can say is you're such an inspiration, your videos are brilliantly put together and you're a natural at teaching! I'm doing a physics degree myself and your video's covering your PhD were really insightful, I loved them! Well done mate, I've subscribed and will keep following your work! :)

[evieherriot]

This is very interesting! Thanks Simon! :D

[gytisvejelis]

Great video as always! Keep up the good work, Doctor Clark!

[drealbrownie]

Simon amazing video! I find your videos amazing and very very interesting, thanks for them!😊

[abhijeetghodgaonkar]

Excellent video Simon, just excellent scripting for this video!!!

[CodeCommand]

The action is the opcode and the address in this instance is the operand, just so people don't get confused, you may see these being referred to online

[zulfur]

I Have been loving all the videos that you have posted lately ! It’s a shame that such good quality videos aren’t getting more views :(

[MrAitorSJ]

OMG I've always wanted to know this. Keep making great content :)

[incianali]

This was amazing and very helpful. Thanks!