Speaker 1: Get in touch with technology with tech Stuff from how
Speaker 1: stuff works dot com. Be there and welcome to tech Stuff.
Speaker 1: I'm your host job in Strickland. I'm an executive producer
Speaker 1: and I love all things tech. And today it's time
Speaker 1: for another classic episode of tech Stuff. We are going
Speaker 1: all the way back to January second, two thousand twelve,
Speaker 1: and we're going to learn about random access memory in
Speaker 1: an episode we called tech Stuff goes to raming speed.
Speaker 1: Chris Palette and I decided to demystify the concept. How
Speaker 1: did we do? Well, let's find out. Today we're gonna
Speaker 1: be talking about memory, computer memory specifically. Yeah, and uh, well,
Speaker 1: you had a lot of people request over over the
Speaker 1: length of tech Stuff. Really the entire time we've been
Speaker 1: doing this, we have a lot of people ask us
Speaker 1: to do a podcast about RAM and to kind of
Speaker 1: talk about what RAM is, why you need it, and
Speaker 1: what does it do and how does it work? Which
Speaker 1: is funny because we kept not doing it because we
Speaker 1: thought we already had it. Turns out not so much.
Speaker 1: I did a search for the word RAM in our
Speaker 1: archives and uh saw a lot of programs but not RAM.
Speaker 1: And I even search for memory and the only memory
Speaker 1: thing we've done is we've talked about hard drives, which
Speaker 1: hard The relationship between hard drives and memory is a
Speaker 1: close one. It's an important one. And Uh, in fact,
Speaker 1: if we did not have RAM, if we if we
Speaker 1: had not developed that, and we were relying solely upon
Speaker 1: the kind of memory that you would find in a
Speaker 1: typical hard drive, you know, the traditional hard drive. UH,
Speaker 1: computer operations would take much longer than what we're accustomed to. Yeah.
Speaker 1: As a matter of fact, I can I can actually
Speaker 1: deliver a personal commentary on that because my very first
Speaker 1: machine was an Amiga one thousand. Many people have known
Speaker 1: because I mentioned it several times in the podcast, and
Speaker 1: that first machine that I had didn't have a hard
Speaker 1: drive on it. Um So Commodore's instructions when you first
Speaker 1: turn the machine on, you would once it it got
Speaker 1: into boot up mode, you would see a copy of
Speaker 1: the Kickstart disc. Kickstart basically loaded the operating system uh
Speaker 1: into RAM, into random access memory, and then once that happened,
Speaker 1: you could launch your workbench, which is the equivalent of
Speaker 1: the desktop in what you would see in Windows Linux
Speaker 1: or the mac os today. Um So, you know, without that, uh,
Speaker 1: you know, when I got my first hard drive computer
Speaker 1: which was an Amigia three thousand UM. It had a
Speaker 1: forty megabyte. Yeah, you can laugh at that hard drive
Speaker 1: which would automatically load the kickstart and get everything started
Speaker 1: up for you. So it worked very much like our
Speaker 1: machines do now. But um, you know that that was
Speaker 1: That's one of those things that the hard drive takes
Speaker 1: care of that you didn't. That you don't have to
Speaker 1: do uh now is load your operating system and all
Speaker 1: that stuff in there. There's also it's also important to
Speaker 1: note the difference between RAM and ROM. I would say
Speaker 1: read only memory or rom UM also has a lot
Speaker 1: of that baked into the chips onto your computer. There
Speaker 1: are some things that are already in your computer that
Speaker 1: are part of the uh um the physical hardware. But
Speaker 1: and and read only memory uh that memory is at
Speaker 1: access sequentially rather than at random, which is how random
Speaker 1: access memory got its name, right, and read only memory,
Speaker 1: as the name implies, you can only read from that memory.
Speaker 1: You can't write to it. So in other words, it's unchanging.
Speaker 1: It is is static. It will always be the way
Speaker 1: it is unless you were to physically remove the chips
Speaker 1: and replace them with other chips or other circuitry, it's
Speaker 1: always going to be the same way. And there's some
Speaker 1: devices that only have read only memory because that's all
Speaker 1: they require, and it's important to have. It's um it's
Speaker 1: a very useful type of memory. But when you're working
Speaker 1: on a project, if you only have ROM and not RAM,
Speaker 1: you would have to burn a new ROM every time
Speaker 1: you wanted to save something. To this I would be
Speaker 1: a real pain. So, for example, if you were to
Speaker 1: look at the good old video game console market, especially
Speaker 1: if you were looking at the old cartridge based consoles,
Speaker 1: the the games, the cartridges you have that you would
Speaker 1: put plug into your console had ROMs on them. That
Speaker 1: was the game itself was a ROM. And that's why
Speaker 1: if you talk about things like the main emulator, and
Speaker 1: I know that's it's kind of like saying a t
Speaker 1: M machine, but the emulator for arcade machines UH that
Speaker 1: you can run on certain computers. The emulator's job is
Speaker 1: to to mimic the circuitry that you would find within
Speaker 1: an arcade machine to run a specific ROM or game.
Speaker 1: So RAMS are used in devices, and in some cases
Speaker 1: are are the only thing within that device. There might
Speaker 1: be some other memory there to do things like keep
Speaker 1: track of a high score. That's a little different. But
Speaker 1: but in general, um, you know, there are certain devices
Speaker 1: that will only have ROM. RAM, however, is very important
Speaker 1: for the way we use computers today. Think of RAM
Speaker 1: as it's a it's a temporary storage fability, yeah, for
Speaker 1: a computer. Right. So it's where you can temporarily store
Speaker 1: instructions and data so that your computers processor doesn't have
Speaker 1: to go hunting through your hard drive system in order
Speaker 1: to find the relevant information to execute a command. Um.
Speaker 1: The way I like to think about this is if
Speaker 1: you're a student, imagine that you have a textbook filled
Speaker 1: with facts, will say physics. It's a physics textbook, all right,
Speaker 1: And you've got a test coming up, and you've created
Speaker 1: a crib sheet for you to study from, and the
Speaker 1: crib sheet has bulleted points on it about the major
Speaker 1: things you're going to be covering in your next physics test.
Speaker 1: That crib sheet is kind of like RAM in the
Speaker 1: sense that you can make little notes, you can erase stuff,
Speaker 1: you can replace things, and it has a good instruction
Speaker 1: set for you to work from. Now, occasionally you might
Speaker 1: come across a problem. Let's say you're working on some
Speaker 1: homework that's going to prepare you for this test. And
Speaker 1: you've got your crib sheet in front of you, and
Speaker 1: you're working on your homework question, and you realize that
Speaker 1: the information that you need is not on the crib sheet.
Speaker 1: It's just doesn't go that deep. So you have to
Speaker 1: go to the textbook to refer to the right section
Speaker 1: to learn the stuff you need in order to answer
Speaker 1: that question. That's kind of like your computer. Your CPU
Speaker 1: is going to refer back to the memory to see
Speaker 1: if the information it needs is there, and if it's
Speaker 1: if the information goes beyond that little memory, if it's
Speaker 1: something that has to actually access the hard drive, it
Speaker 1: will go to the hard drive. Same sort of idea. Yeah,
Speaker 1: And UM, I would just like to note that when
Speaker 1: I said that ROM could only be access sequentially, that's wrong.
Speaker 1: I was actually thinking of serial access memory or SAM. Right.
Speaker 1: I apologize for that. Yeah, I haven't had enough coffee
Speaker 1: this morning apparently, But yeah, serial access memory is UH
Speaker 1: is another form of memory that's not used nearly as
Speaker 1: often today as it used to be. But back when
Speaker 1: we had tape drives, UM, you know, you used to
Speaker 1: have to go all the way through the tape until
Speaker 1: you got to the part where it had the information
Speaker 1: you needed letter than accessing it. It's just the same
Speaker 1: as if he's had a cassette tape. Right. If you
Speaker 1: had an old cassette tape with music on it and
Speaker 1: you wanted to listen to a specific song, you had
Speaker 1: to fast forward or play through the tape until you
Speaker 1: got to the song you wanted, and then you could
Speaker 1: listen to it. You couldn't just jump right to the song.
Speaker 1: For our younger listeners, this might seem like a completely
Speaker 1: foreign concept, but yes, uh, lots of us used to
Speaker 1: listen to cassette tapes and if you were really lucky,
Speaker 1: you had like the eight track tapes where your options
Speaker 1: were even more limited in order to to navigate to
Speaker 1: the next song. Yes, but ROM doesn't necessarily work that way,
Speaker 1: so I apologize for that. But random axis memory there,
Speaker 1: there's certain there are different kinds of it. One of
Speaker 1: the most common is dynamic RAM. Yeah, that's that's probably
Speaker 1: the most versions of that are probably the most common
Speaker 1: used in computers today. Yeah, and uh, And the way
Speaker 1: that random axis memory, dynamic random access memory is is
Speaker 1: arranged is that you can imagine a grid, right, and
Speaker 1: the columns there are columns, and there are rows, and
Speaker 1: where these intersect you have memory cells. Now, a memory cell,
Speaker 1: the most basic memory cell is essentially a transistor and
Speaker 1: a capacitor, and the capacitor can hold a charge. If
Speaker 1: the capacitor is holding a charge, the memory cell is
Speaker 1: registering as a one. If the capacitor is not holding
Speaker 1: a charge, it's registering as a zero. The transistor access
Speaker 1: a switch that allows the various things. It allows the
Speaker 1: computer to be a to read those particular cells and
Speaker 1: also to recharge those cells. Because here's the thing about capacitors,
Speaker 1: they do drain. Yeah, they can hold a charge. There.
Speaker 1: They're sort of like a battery, though they are not identical,
Speaker 1: so don't assume that that's the same thing, but there
Speaker 1: they fulfill similar functions. Capacitors usually release their energy in
Speaker 1: a burst as opposed to over a prolonged time. But yeah,
Speaker 1: the capacitors the the energy drains from the capastors, so
Speaker 1: they have to be recharged regularly and rapidly in order
Speaker 1: for them to maintain that charge and hold onto what
Speaker 1: we call a state, the state of that memory cell.
Speaker 1: So the state is either a one or a zero.
Speaker 1: If it's a one, the computer has to continually send
Speaker 1: energy to that UH cell in order for it to
Speaker 1: maintain a one until the memory needs to be written over,
Speaker 1: in which case it might be a one again or
Speaker 1: it might be a zero. It all depends on what
Speaker 1: the information is. And you've got the like I said,
Speaker 1: you've got columns and you've got rows, and uh, the
Speaker 1: way the computer works, it has all these different little
Speaker 1: UM components to it that will detect what the current
Speaker 1: state is of all those different memory cells in order
Speaker 1: to be able to uh to to pull the right information.
Speaker 1: And in fact, the computer keeps a record of which
Speaker 1: memory you sell it needs to go to because you
Speaker 1: can think of the intersection of that column in that
Speaker 1: row as an address. Yeah, if you think about it
Speaker 1: as a piece of graph paper. Yeah, kind of the
Speaker 1: computer just basically keeps track of, uh, you know, where
Speaker 1: each item is in that memory. Yeah. If you think
Speaker 1: of the columns is like things like A, B, C, D, E, F.
Speaker 1: You know, sort of like think of it kind of
Speaker 1: like a game of battleship. That's exactly what I was thinking. Yeah,
Speaker 1: you got that. You've got the columns that are maybe
Speaker 1: A through Z, and then you have one through twenty
Speaker 1: six as the rose and you want to look at
Speaker 1: a four, well, then you know exactly where to go
Speaker 1: to to pull up that information. You don't have to
Speaker 1: you don't have to go through the entire ce quence
Speaker 1: of memory cells in order to get that information. That's
Speaker 1: a very simplistic way of saying what is happening with
Speaker 1: this dynamic random access memory. One of the disadvantages here, though,
Speaker 1: is that having to refresh that memory constantly means that
Speaker 1: you're essentially slowing down the memory. UM, which is you
Speaker 1: know a problem. It's it's something that that requires a
Speaker 1: lot of energy. It requires uh that you're constant constantly
Speaker 1: refreshing it and slows down your memory. Now, um, having
Speaker 1: more memory and your computer is a good thing. UM.
Speaker 1: You remember when we talked about thirty two bit and
Speaker 1: sixty four bit systems. Um. You know, your your operating
Speaker 1: system and your computer, depending on how they work together,
Speaker 1: can address a certain amount of computer memory. UM. And
Speaker 1: uh you know with if you have if you are
Speaker 1: not taking advantage of the maximum capacity of memory or
Speaker 1: at least you know, the as much as your computer
Speaker 1: can hold. UM. Not only is it having to uh
Speaker 1: fit whatever programs you're trying to run on top of
Speaker 1: the operating system in that amount of memory, it's also
Speaker 1: dealing with uh constantly having to refresh that memory, so
Speaker 1: it can really slow your computer down. We're gonna take
Speaker 1: a quick break to thank our sponsor, and then when
Speaker 1: we come back more about RAM. Going back to the
Speaker 1: grid really quickly. The the columns along this grid are
Speaker 1: called bit lines, the rows are called word lines, and
Speaker 1: then the the intersection is the memory cell address. So,
Speaker 1: UH though, what when you are WIN, when you want
Speaker 1: to write information or when your computer needs to write
Speaker 1: information to your RAM in order for the CPU to
Speaker 1: be able to have access to it to make things
Speaker 1: run smoothly. First it starts sending electricity through the column area,
Speaker 1: so through the bitline UM individual bitline, and then the
Speaker 1: computer sends electricity through the appropriate wordlines the right rose.
Speaker 1: So let's say that you you know that you're you're
Speaker 1: you're activating column D that's the one that's being UM
Speaker 1: that electricity is running through right now. And you know
Speaker 1: that Rose five, twelve, and twenty three need to have
Speaker 1: need to be activated because those memories, the memory cells
Speaker 1: at those addresses at the intersection of column D UH
Speaker 1: need to be active in order for the information to
Speaker 1: be there. The computer sends this information, the transistor allows
Speaker 1: the capacity turns to take on that that charge. And
Speaker 1: then there's a little um sensor actually since amplifier as well,
Speaker 1: that receives the signal that says this capacitor has has
Speaker 1: a state of one, and that's what allows the computer. No,
Speaker 1: you know if it's a one or zero, and collectively
Speaker 1: all those ones and zeros give it the information it needs. Now,
Speaker 1: all of this happens in a manner of a few nanoseconds,
Speaker 1: So don't think like this is taking ages. It's it's
Speaker 1: it's billions of a second for this stuff. When I
Speaker 1: say slow, I would put that in quotes. It's slow,
Speaker 1: right slow, like the way we feel when we put
Speaker 1: something in the microwave for a minute and we're thinking,
Speaker 1: why isn't it done yet? That kind of slow slow
Speaker 1: as relative. Yes, it's not slow as in you put
Speaker 1: something in the oven and four days later you've got turkey.
Speaker 1: Uh the I put an old boot in there. There's
Speaker 1: a turkey. That's the way it worked, isn't it. No? Oh,
Speaker 1: I need to go home after this podcast, but at
Speaker 1: least I'll have some warm boots Uh yeah, so this
Speaker 1: this is all taking just nanoseconds for each individual transaction,
Speaker 1: no seconds the whole thing. So, but it's happening repeatedly
Speaker 1: until that memory is getting rewritten, and it's happening. You know,
Speaker 1: it's changing rapidly because that's the nature of memory. If
Speaker 1: you're running a lot of different applications, and uh, your
Speaker 1: memory might be filling up pretty quickly with all this information.
Speaker 1: That's why the more applications you run, if you're if
Speaker 1: you're using an older machine and you're running a lot
Speaker 1: of different applications, you might feel like you're everything's kind
Speaker 1: of sluggish. And that's why people will tell you like, oh, well,
Speaker 1: you need to close some of these applications because it's
Speaker 1: taking up space in the memory and the CPU is
Speaker 1: having to work harder to get the information it needs
Speaker 1: to act to execute your commands. So uh, you know
Speaker 1: that that's how that all plays in. That's why people say, oh,
Speaker 1: if you want a computer to go faster, you need
Speaker 1: more memory, because then you can you can actually run
Speaker 1: more applications. That tends to be a very common problem
Speaker 1: that people run into, right They're like, my computer is
Speaker 1: so slow, and you look at it and you're like, well,
Speaker 1: you've got fifteen applications open, and three of them are
Speaker 1: pretty heavy duty, um, you know, or graphics intensive or whatever,
Speaker 1: something that's going to require a lot of processing. That
Speaker 1: would be why it's both processor speed and the amount
Speaker 1: of memory you have. The two are very much important.
Speaker 1: And also when we talk about Moore's law, Moore's law
Speaker 1: plays into the into memory as well, because dynamic random
Speaker 1: access memory the nice thing about it is that, well
Speaker 1: two nice things about is that it's relatively inexpensive, and
Speaker 1: it's it doesn't take up a lot of physical space
Speaker 1: when you're designing memory chips. There are other types of
Speaker 1: random access memory, not just dynamic their static random access memory.
Speaker 1: And static random access memory uses uh something a logic
Speaker 1: construction called a flip flop. Yes, not a standal I
Speaker 1: was gonna say, you're gonna oven and it comes out
Speaker 1: as chicken already know that doesn't work. Well, the static
Speaker 1: random access memory, Um yeah, I mean it one of
Speaker 1: the benefits of us now flip flops. Actually we uh
Speaker 1: you go back to the Boolean logic um reference. But
Speaker 1: basically a static RAM has the benefit of being a
Speaker 1: lot faster than dynamic RAM. Well, for one thing, what
Speaker 1: it does. Once it has a state, it will hold
Speaker 1: that state until you tell it to change. So it
Speaker 1: doesn't it doesn't, it doesn't require to be recharged, doesn't
Speaker 1: have a capacitor that is leaking energy and has to
Speaker 1: be refilled. So so once you once you set a
Speaker 1: flip flop to one, it's going to stay a one
Speaker 1: till you tell it to be a zero. So that
Speaker 1: sounds great. Why don't we use static RAM instead of
Speaker 1: dynamic RAM for our you know, main RAM in our computers?
Speaker 1: Two reasons. One, it takes up more space, so you
Speaker 1: end up having problems like especially with things like mobile
Speaker 1: devices or or laptop computers, you start running into the
Speaker 1: problem of while you can only fit so much into
Speaker 1: a four in factor before he gets clunky, right right,
Speaker 1: you need more transistors for static RAM. Yeah, yeah, four
Speaker 1: to six for each flip flop. So that's and each
Speaker 1: flip flop is is representing one memory cell. So and
Speaker 1: granted these transistors that we're talking about are on the
Speaker 1: nanoscale at this point, you know, we're talking about tiny, tiny,
Speaker 1: tiny transistors. But even so those add up if you
Speaker 1: need to have the amount of memory that you're accustomed to,
Speaker 1: so they are they take up more space, and they're
Speaker 1: more much more expensive. So static RAM is not something
Speaker 1: you're gonna find in every single kind of device, although
Speaker 1: as you know, as the technologies improved, those prices do
Speaker 1: tend to go down, so we do see more and
Speaker 1: more of that, but dynamic RAM is still probably I
Speaker 1: would say the most popular by far. Um. There there's
Speaker 1: another potential change coming up, a new development that could
Speaker 1: really uh impact this, which we can get into in
Speaker 1: a little bit. Okay, Yeah, I was gonna mention too though,
Speaker 1: that that's attic RAM can be found in your computer,
Speaker 1: probably because um, if you've seen a list of computer specifications,
Speaker 1: perhaps when you're shopping for a new machine and you
Speaker 1: see the cash referred to, um, your computer's cash is
Speaker 1: uh probably static ram. Yeah. A lot of CPUs have
Speaker 1: this built in, uh, A lot of the ones that
Speaker 1: use multi threading, that have multi core processors. A lot
Speaker 1: of these CPUs have their own sections of memory built
Speaker 1: And it's not it's not your computer's RAM. It's something
Speaker 1: that's specifically part of the CPU chip set that is
Speaker 1: there to help make make those those data transfers even
Speaker 1: faster so that it makes it very efficient and for
Speaker 1: the the most commonly used commands, uh, those would be
Speaker 1: stored within the cash. So in that crib sheet example
Speaker 1: I gave, let's say that you even had a little
Speaker 1: note card next year, a crib sheet that had the
Speaker 1: four formulas you're going to use them most frequently in
Speaker 1: that physics test, and so you've got those there. Because
Speaker 1: this way, no matter what you know, you just have
Speaker 1: to glance at the at the note card like that's
Speaker 1: that's the formula I need, and you plug it in
Speaker 1: and you make it, you make it work and whatever.
Speaker 1: The problem is. Your CPU is really really good at
Speaker 1: executing operations upon data, but it's stupid in the sense
Speaker 1: that as soon as it's as soon as it's finished
Speaker 1: doing that, it's forgotten. There's no Yeah, it has no
Speaker 1: memory of its own other than this this cash that
Speaker 1: we're talking about. A CPU on its the very basic
Speaker 1: CPU has no memory, so it can do stuff, but
Speaker 1: as soon as the task is done, it's like a
Speaker 1: blank slate all over again. That's that's why we have
Speaker 1: to have memory in order to get this to work.
Speaker 1: If if the CPU could somehow remember on its own,
Speaker 1: then you'd have other issues like well, now needed to
Speaker 1: do something new, So how do you write over what
Speaker 1: you had before? Do you just add to it? If
Speaker 1: you add to it, how long until you reach capacity?
Speaker 1: And you can't do anything with that CPU other than
Speaker 1: the stuff that you've already done. So you know, this
Speaker 1: is why the whole idea of the random actis memory
Speaker 1: that could be rewritten very quickly was so important because
Speaker 1: otherwise you limit the functions that your computer is capable
Speaker 1: of doing. You know, this computer is great at adding
Speaker 1: and subtracting and dividing, and after that you can't do
Speaker 1: anything else because that's I was about to install Pacman,
Speaker 1: but darn it, I already took up all of its
Speaker 1: space with these three functions. Well, yeah, so you've got
Speaker 1: and and we're we're sort of filling out the whole computer.
Speaker 1: So you've got your your CPU, and you've got a
Speaker 1: cash to help it remember stuff that it needs to
Speaker 1: do basic operations, right, and then you've got your your memory,
Speaker 1: your RAM, your dynamic RAM that that's over here managing
Speaker 1: the stuff that you've got going on, your word pressing,
Speaker 1: your word uh processor uh stuff, and your your graphics program,
Speaker 1: the stuff that you have brows your browser, your your
Speaker 1: email program. But you also have UH in your modern computer,
Speaker 1: you've got your graphics processor chip. And in a lot
Speaker 1: of cases, UM, and I'm just hedging my bets here
Speaker 1: that somebody has some weird computer that doesn't have this
Speaker 1: also has its own RAM UM to help it pro
Speaker 1: specifically process graphics. UM. So that RAM in general is
Speaker 1: off limits to the rest of the machine because it's
Speaker 1: saying no, no, no no. This memory is specifically to
Speaker 1: help us render graphics on the screen so that the
Speaker 1: user can UH see everything that he or she wants
Speaker 1: to see from the other programs. So it's not handling programs,
Speaker 1: it's handling graphics. We have we have seen some processors
Speaker 1: recently that are able to tap into the graphics processing
Speaker 1: units as well and be able to to utilize those
Speaker 1: two process particularly difficult problems or powerful, you know, time
Speaker 1: consuming problems to try and reduce the amount of time
Speaker 1: it takes to get through that application. So and in fact,
Speaker 1: we're seeing we're seeing both sides, right. We're seeing UH
Speaker 1: CPU manufacturers get into adding in elements that specifically tackle
Speaker 1: graphics processing, and we've seen graphics processing unit manufacturers get
Speaker 1: into handling more basic processing UH functions. So the two
Speaker 1: worlds have been colliding for probably less well for for
Speaker 1: quite a quite a while, but really visibly for the
Speaker 1: last two years. Yeah, I'm thinking specifically of Apple's Grand
Speaker 1: Central Technology, one of those things in snow Leopard that
Speaker 1: people didn't really care about, but it was actually supposed
Speaker 1: to improve the operating system, but it was mainly thinking
Speaker 1: of Intel Sandy Bridge, which had its own graphics processing
Speaker 1: element added into it. And the thing is that, uh
Speaker 1: so that so the rule that we were just talking
Speaker 1: about is is going to be shifting as time goes on,
Speaker 1: and uh processor manufacturers of all kinds are more sophisticated,
Speaker 1: the operating systems become more sophisticated and able to take
Speaker 1: advantage of these changes. Um. But that's kind of the
Speaker 1: way it works out. And I just wanted to illustrate
Speaker 1: the fact that RAM can be used to support a
Speaker 1: number of computer functions. You'll also see it in you know,
Speaker 1: all kinds of other devices that use memory. Cameras, um cars,
Speaker 1: all kinds of technologies that use computer processing that you
Speaker 1: may or may not necessarily think of as of having
Speaker 1: computers inside, but you know they have some form of
Speaker 1: RAM in there. Chris and I have a little bit
Speaker 1: more to say about random access memory, but before we
Speaker 1: get to that, let's take another quick break to thank
Speaker 1: our sponsor. Now, of course RAM has gotten more sophisticated
Speaker 1: itself over time too. And you do you want to
Speaker 1: talk about, uh, some of the older types or do
Speaker 1: you want to talk about the improvements you were just
Speaker 1: about to mention? Well, um, I have something leading up
Speaker 1: into the improvements. If you have, if you have information
Speaker 1: about older types of memory, I'm more than happy to
Speaker 1: hear it. I personally did not research that, so I
Speaker 1: have none of that information in front of me. Okay, alright, well, um,
Speaker 1: I have some of it. And really this could probably
Speaker 1: get kind of dry, um, but basically, you know, as
Speaker 1: as time has gone on, you've been able to see
Speaker 1: you were talking about Moore's law, which of course says
Speaker 1: that the number of transistors on a processor chip will
Speaker 1: double in Well, originally it was two years, now in
Speaker 1: half or wait, I'm sorry, that's backwards. If Yeah, it
Speaker 1: tends to go back and forth. Between twelve months to
Speaker 1: twenty four months and eighteen to twenty four tends to
Speaker 1: be the most frequently cited figures. So depending on any
Speaker 1: given year, you'll hear. Oh, well, it's one of the
Speaker 1: things that the Moore's law gets gets validated in retrospect, right,
Speaker 1: because you have to look back two years ago and
Speaker 1: look and see how many transistors were found on a CPU,
Speaker 1: or like we're staying here, a memory circuit. That also
Speaker 1: can apply. If you can fit twice as many transistors
Speaker 1: on the memory circuit, then that's another example of Moore's
Speaker 1: law holding true. M Um. But yeah, basically, as far
Speaker 1: as the memory chips have gone, there's been a wave
Speaker 1: of advances over the last couple of decades in which
Speaker 1: more and more processors are are added. The way that
Speaker 1: their accesses has changed. I remember with my Amiga three
Speaker 1: thousand they used a very unusual type of memory called zips,
Speaker 1: in which the pins that you use to plug them
Speaker 1: in were basically a zig zag. There was a pin
Speaker 1: on one side, then there was one on the other side,
Speaker 1: there was one on the other side, you know, and
Speaker 1: flipped back and forth between them. Only a very few
Speaker 1: computers used that type of technology. UM. When I got
Speaker 1: a Mac it used sims UM, which is a single
Speaker 1: inline memory module. UM. You can actually find quite a
Speaker 1: bit about the different types of memory on We referred
Speaker 1: to it in our how ram works article on how
Speaker 1: stuff Works dot com. But it's on Kingston's website and
Speaker 1: it's UM. You know. It talks about the different types.
Speaker 1: But the single inline modules were an improvement over that
Speaker 1: the older technology, and then they came out with the
Speaker 1: dual inline memory modules UM, and they basically it's a
Speaker 1: little itty bitty card. UM. It's long, UM, but it
Speaker 1: has a series of chips soldered into it. UM and
Speaker 1: those are the memory chips, right. And the old days
Speaker 1: you actually had to install a memory chip directly into
Speaker 1: the motherboard. Yeah, this is the this sort of predates
Speaker 1: the more i would say, the nineties and two thousands computers.
Speaker 1: This is like the eighties and the old four right.
Speaker 1: So if you want to upgrade your comp it or
Speaker 1: it actually meant opening up your computer, man, disconnecting the
Speaker 1: motherboard and then possibly um, depending on how the memory
Speaker 1: chip was designed, you might even have to do some soldering.
Speaker 1: But but get you know, install a new memory chip
Speaker 1: so that your computer would have more memory eventually. Improvements included, uh,
Speaker 1: designing something called a memory bank where you had a
Speaker 1: port essentially that you could plug in a card that
Speaker 1: had a certain number of memory chips of a certain capacity,
Speaker 1: and then as technology improved, you could replace that card
Speaker 1: with a card that had a greater capacity. Now, keep
Speaker 1: in mind that your computer CPU would determine how much
Speaker 1: memory your computer could actually use. There would you would
Speaker 1: reach a point where it wouldn't matter if you could
Speaker 1: buy a card with more memory, your CPU wouldn't be
Speaker 1: able to access it, and had had limitation on that.
Speaker 1: So there were you know you that's why if you
Speaker 1: were to look at computer specs and see like, you know,
Speaker 1: upgradeable up to whatever, that's the reason why is that
Speaker 1: the CPU itself has that limitation and so um you
Speaker 1: know something, you know, the in America at least, we
Speaker 1: have this philosophy of more is better, But there's a
Speaker 1: certain point where, depending on the machine you're using, more
Speaker 1: isn't going to do you any good because your computer
Speaker 1: simply cannot use it. Yeah, and that's actually sort of
Speaker 1: the source of Jonathan's earlier quote. UM, I mean, just
Speaker 1: the idea behind it is that you know, there's only
Speaker 1: so much you can use. Um. DEM's actually had chips
Speaker 1: on both sides of that uh circuit board, and we're
Speaker 1: able to handle more memory and more quickly. And you know,
Speaker 1: from there we've moved UM move forward. I won't get
Speaker 1: into to all of it, but we really got into
Speaker 1: the more advanced types of memory and the two thousands
Speaker 1: when we got into UM UH, the UM dynamic RAM
Speaker 1: and that that made things a lot more And basically
Speaker 1: what they've done is, over the period of time, made
Speaker 1: the transfer of information more efficient. They've increased the number
Speaker 1: of transistors and the amount of information that could be
Speaker 1: stored on a single UH card with the RAM in it.
Speaker 1: And it's just it's just done. Some made some insignificant
Speaker 1: improvements over the past few years. Right. And and memory
Speaker 1: relies on something called a memory controller. Yes, that's part
Speaker 1: of what maintains like it determines UH when to write
Speaker 1: two memory cells. It also helps read the memory cells
Speaker 1: that it's it's kind of like a manager, right. But
Speaker 1: it also has to check the memory whenever it's getting
Speaker 1: information back from memory, has to check it for errors.
Speaker 1: And depending on what kind of system you're using, you
Speaker 1: might have a memory chip with just with a built
Speaker 1: in error checking technology which is called a parody check. Yes,
Speaker 1: so checking for parody to make sure that the information
Speaker 1: it's it's delivering is accurate. Uh. Um. There are a
Speaker 1: lot of different ways of doing this, but um one
Speaker 1: is so we talked about information in in the computer
Speaker 1: world in terms of bits and bytes, right, and a
Speaker 1: bite is eight bits, which kind of represent a unit
Speaker 1: of information, of useful information, because each bit is itself
Speaker 1: a unit of information, but in order for it to
Speaker 1: be useful for a computer, we we group them in
Speaker 1: groups of eight uh. Standard. Now, though it wasn't when
Speaker 1: computers first were developed, there were several different competing UM.
Speaker 1: I guess you could calm standards because they were standard
Speaker 1: amongst a certain group of computers. But we kind of
Speaker 1: selled on this whole eight bit is a byte model,
Speaker 1: and with parody they there's an extra bit added on
Speaker 1: to the end. And uh that bit is it's kind
Speaker 1: of a marker, right, Yeah, it's basically used for error checking. Yeah.
Speaker 1: So if if the uh, for example, it looks at
Speaker 1: how many of the bits within that bite are ones
Speaker 1: versus zeros. So if all of the if there are
Speaker 1: an odd number of ones in that byte, remember it's
Speaker 1: eight bits, there's an odd number, the parody bit is
Speaker 1: set to one. If it's an even number, the parody
Speaker 1: bit is set to zero. So then when the data
Speaker 1: is being processed, the totals added up again and it's
Speaker 1: checked against the parody bit. Now, if that matches, the
Speaker 1: assumption is that the that byte is correct, it's accurate,
Speaker 1: and everything's cool. If it comes up as a conflict,
Speaker 1: then that's a message to say, dump this information because
Speaker 1: something has gone wrong. Now, the parody bit does not
Speaker 1: tell you what the information is. It just is a
Speaker 1: shorthand way of saying, all right, are there an even
Speaker 1: number of ones in this byte? Yes, well, then something's
Speaker 1: gone wrong. It doesn't tell you what the information is
Speaker 1: or why it's wrong. It just says that's not what
Speaker 1: I got when I added it up, right, So uh.
Speaker 1: And then there's that that's called even parody. That's that
Speaker 1: particular model. That's just one way of doing it. There's
Speaker 1: also odd parody, which is kind of the same idea,
Speaker 1: except you know, if it's an odd number of ones,
Speaker 1: then it's considered a zero. If it's an even number
Speaker 1: of ones, it's considered a one. But uh. There's also
Speaker 1: the error correction code method, which goes a little bit further.
Speaker 1: This is this is so you've got parody that tells
Speaker 1: you there's a problem error correction is to try and
Speaker 1: step in when there's a problem and fix it. Um.
Speaker 1: It uses additional bits to monitor the information that the
Speaker 1: actual information that's in the byte. So um, it's looking
Speaker 1: at the information itself, not just a summer um. And
Speaker 1: it uses pretty complicated algorithms to try and head off
Speaker 1: any problems. So there, you know, this has to be
Speaker 1: built in because occasionally things go wrong. Sometimes something doesn't
Speaker 1: trip when it's supposed to trip, and uh, your CPU
Speaker 1: doesn't necessarily know that you. CPU is just working on
Speaker 1: what's given to it. So again, since the CPU can't
Speaker 1: remember what it did last in its last nanosecond, it's
Speaker 1: just saying, all right, I gotta execute this particular operation
Speaker 1: against this particular set of information. It doesn't know or
Speaker 1: care if it's the correct operation or information set. So
Speaker 1: you have to have that error correction in there. In
Speaker 1: some places, it's not always in the memory controller chip.
Speaker 1: Sometimes it's part of the CPU. It's it all depends
Speaker 1: on the architecture of the computer system itself. Yeah. Now, um,
Speaker 1: it's also important to note um uh that as my
Speaker 1: uh improvements have changed, the way of of doing this
Speaker 1: has changed, and of course that probably the the type
Speaker 1: of RAM that you have in your computer, if you've
Speaker 1: got a more recent uh computer, is the aversion of
Speaker 1: the double data rate synchronous d RAM dynamic RAM or
Speaker 1: U d d R and you know d d R
Speaker 1: two d d R three um s d RAM. But
Speaker 1: that's uh, you know, that's changing. As you were saying,
Speaker 1: their improvements being made. I know. One of the types
Speaker 1: of memory that people have been talking about is magnetic RAM,
Speaker 1: which is supposed to basically give you an instant on
Speaker 1: uh situation when you turn your computer on, because uh,
Speaker 1: it can store the information and pull it up immediately
Speaker 1: and you don't have to worry about a long boot
Speaker 1: up sequences. The RAM is getting uh populated with information, right. Yeah.
Speaker 1: The idea here is to have something, some sort of
Speaker 1: system in place that can maintain a state without the
Speaker 1: need for uh the electrical impulse to go through and
Speaker 1: boot it up. Right. So another potential solution, although this
Speaker 1: is one that is still being developed, is the memorister. Yes, memoristers,
Speaker 1: and these are interesting things. Uh, it's kind of difficult,
Speaker 1: it's really complicated to to get into detail. But in
Speaker 1: from a bird's eye perspective, a memorister is an electrical
Speaker 1: component all right, And if you run current through a
Speaker 1: memorister in one direction, the electrical resistance increases. If you
Speaker 1: run current through the opposite way, the resistance decreases. Now
Speaker 1: once the current stops moving through, the memorister holds onto
Speaker 1: whatever the last resistance was. So if you ran it
Speaker 1: through the first way, then the resistance has been stays
Speaker 1: at its increased level. If you if you last ran
Speaker 1: it through the opposite way, then it's going to be
Speaker 1: at its decreased level. That that's a two bit system, right.
Speaker 1: You could assign one of those of one and the
Speaker 1: other one of zero and once you ran through that
Speaker 1: once uh, it would make it would hold on to
Speaker 1: that information. And it takes up much less space than
Speaker 1: the typical memory transistors do, so it's smaller and it
Speaker 1: will hold on to whatever the state is until you
Speaker 1: tell it that you know you want to change by
Speaker 1: by and you tell it by running the electricity through
Speaker 1: it one way or versus the other. The computer have
Speaker 1: to remain plugged in for this to work. No, once
Speaker 1: you've once you've done it, once you've run the current through,
Speaker 1: you can turn the current off and the memorister retains
Speaker 1: that resistance. So the only thing that has to happen
Speaker 1: is the computer has to be able to detect what
Speaker 1: the resistance is of that memorister. So once it detects
Speaker 1: what the state is, then you've got that information already there.
Speaker 1: So it could be used in various kinds of processors
Speaker 1: as well as memory. And because it's smaller, you could
Speaker 1: at least potentially cram far more memory into a smaller
Speaker 1: space than what is capable using right now through transistors.
Speaker 1: So this is this is a potential way to keep
Speaker 1: Moore's law going. In fact, if the developments were to
Speaker 1: progress at a at a good clip, we could almost
Speaker 1: leap frog quite a bit because the potential is that
Speaker 1: it would revolutionize UH processing and memory all in a
Speaker 1: in a a fell swoop, a swell fhoop. Yeah. Now
Speaker 1: I'm not sure that the board would agree. I'm sure
Speaker 1: that they say that anything involving resistance, yeah, but yeah,
Speaker 1: it's it's an interesting idea and it's something that's was
Speaker 1: first proposed back in nineteen one, and UH and HP
Speaker 1: Labs has been working on it diligently. UM and in fact,
Speaker 1: in two thousand and eight announced that it was developing
Speaker 1: switching mem risters. So these are these are the sort
Speaker 1: of technologies that I think are going to become far
Speaker 1: more important in the near future because again we've talked
Speaker 1: about this before about how the world is moving to
Speaker 1: mobile devices literally in some cases, but the mobile devices
Speaker 1: are becoming increasingly important. Well, with a mobile device, you
Speaker 1: have a much more limited amount of space that you
Speaker 1: have to work within, and so something like a mem rister,
Speaker 1: which could at least at least in theory, pack much
Speaker 1: larger punch and a much smaller package. It could create
Speaker 1: the super super duper smartphones that we all want. Super
Speaker 1: smartphones are already on the horizon. Okay, well I have
Speaker 1: secret identities too. Yeah. So so RAM is pretty ubiquitous.
Speaker 1: I mean, it's in just about anything that that computes UM.
Speaker 1: And you know, the technolog G has been fairly standard
Speaker 1: for several years now, um, you know, with minor improvements
Speaker 1: over the past decade or so, but you know, with
Speaker 1: with UH computer scientists working on improvements UH completely different technologies,
Speaker 1: hopefully they'll be able to improve that because it's it's
Speaker 1: critical to basically any type of computing that you want
Speaker 1: or need to do. UM. So it's uh, it's very basic.
Speaker 1: I'm glad we we looked at it because it's, uh,
Speaker 1: it's vastly important to our our daily world these days.
Speaker 1: It's definitely one of the basic building blocks of of
Speaker 1: the computing age. I mean, you know, you talk about
Speaker 1: it's not as it's not as basic as say a transistor, right,
Speaker 1: it's like a level up, so it's kind of on
Speaker 1: the molecule scale as opposed to the atomic scale. Right,
Speaker 1: it relies on transistors, yea, So it's it's a little
Speaker 1: more complex than just the basic basic building blocks. But
Speaker 1: without it, computing would not be nearly as useful as
Speaker 1: it is because it would take far more time to
Speaker 1: process operations. And even again, even if you have the
Speaker 1: fastest CPU, if it can't access memory, then all it's
Speaker 1: going to do is just be very quick when it
Speaker 1: needs to to find information on the hard drive, and
Speaker 1: then it's all dependent upon how fast the hard drive
Speaker 1: can deliver the information to the CPU. The memory allows
Speaker 1: the CPU to skip that step and it just makes
Speaker 1: things much faster. Now, another potential memrister thing I should
Speaker 1: say is that if you designed a hard drive out
Speaker 1: of memristers, you could in theory have your hard drive
Speaker 1: act as memory, it would be it would it could,
Speaker 1: in theory behave in a very similar fashion, which means
Speaker 1: you could potentially just incorporate RAM directly as part of
Speaker 1: what the hard drive does, and then you wouldn't need
Speaker 1: RAM anymore, which also means that you could load stuff
Speaker 1: up at at a in the blink of an eye
Speaker 1: and it would be phenomen at all. Uh. Again, that's
Speaker 1: a potential that we may come to see one day.
Speaker 1: It's not something that you're going to see on the market.
Speaker 1: I don't know else. I haven't gone to see yes yet,
Speaker 1: so maybe hey, look at the memristor machine. And that
Speaker 1: wraps up our classic episode about random access memory. I
Speaker 1: hope you enjoyed it. Always fun to kind of look
Speaker 1: at the basics of technology, especially with my former co
Speaker 1: host Chris Palette, who was a true joy to record with.
Speaker 1: I hope you guys enjoyed this, this glimpse down memory lane.
Speaker 1: If you guys have any suggestions for future episodes of
Speaker 1: tech Stuff, or you just want to reach out and
Speaker 1: say good job, or maybe you want to ask why
Speaker 1: can't Chris do this show instead of you? I mean,
Speaker 1: that will hurt my feelings, but I understand if you
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