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Computer Science from the Bottom Up (2013)

bottomupcs.com

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Re: Computer Science from the Bottom Up (2013)

#41

Post by gravypod »

kazinator wrote: post #32
gravypod wrote: post #5

I've been rattling this idea around in my head and, although it may sound crazy, I think C is a little high level to start an adult out on. I know many people won't agree with this but all of the people I admire in the world of CS and everyone who is a true scottsman for all intents and purposes loves dipping down to a lower level once and a while. I think the best way to learn about computer science it to program fo…

If you have an audience that is even interested in C (they came specifically to learn about it) it is probably safe to assume that they are interested in lower levels of tech simply by the popular association between C and that. People benefit from context. A "how stuff is made" tour might help. I would show the newbies all the steps: how we start with a piece of C source, and go to executable. Here is a simple progr…

That is very top down. This is perfectly fine and the only reason why I think differently is because most of my peers are afraid of experimenting. They think everything they haven't seen is magic.... because well it seems that way. It's voodoo to them. When I see a compiler I just think "pfft, tokenizer, lexer, tree". When they see a compiler they think "I could never understand this in my life".

It's like when I go to my mechanic. I pop the hood, he looks at it, spouts off some Geordi LaForge-sounding nonsense, I pay him and I walk away feeling like I've made out like a bandit! "That moron! That stuffs so complciated this work was worth double that! Hahahaha!"

What's really happening is that my mechanic has touched under the hood and no matter the car he things "eh, I'll figure it out". Or "How hard could it be? I'f fixed thousands of cars and thousands of problems, I know what's wrong already!"

He gained that experiance from actually messing around under the hood. Not from driving the car at a high level like I have but from sticking his hands in and getting into the nitty gritty.

Going from the top down leaves people affraid to push further down into their machine. This is the fear of infinite complexity that they think is hiding under the surface. The truth is that all computer science material of of constant complexity when looked at on it's plane of theory. IF everything has been correctly abstracted and defined then nothing should be "complicated" but it should be "entierly understandable". Anyone who gets the basics should be able to go "eh, I'll figure it out" when referencing any part of the computer if it has been correctly implemented.

Re: Computer Science from the Bottom Up (2013)

#42

Post by vvanders »

userbinator wrote: post #38
gravypod wrote: post #5

I've been rattling this idea around in my head and, although it may sound crazy, I think C is a little high level to start an adult out on. I know many people won't agree with this but all of the people I admire in the world of CS and everyone who is a true scottsman for all intents and purposes loves dipping down to a lower level once and a while. I think the best way to learn about computer science it to program fo…

I also advocate for starting with the low-level basics, although slightly lower - logic gates. Students should start off building circuits using 74-series ICs on a breadboard, while learning about Boolean logic. If the resources to work with actual hardware aren't available, a logic simulator should suffice. This is something that I think even young kids would be comfortable with doing: simple circuits to "compute" s…

I'd actually argue an FPGA/CPLD is a slightly better approach, simply because you have block memory that acts very much like "cache" and makes it abundant why system memory is so much slower.

Since you have timing statistics it also makes it really easy to demonstrate pipelining and many other modern "quirks" of processors that have a large impact on performance.

Re: Computer Science from the Bottom Up (2013)

#43

Post by gravypod »

userbinator wrote: post #38
gravypod wrote: post #5

I've been rattling this idea around in my head and, although it may sound crazy, I think C is a little high level to start an adult out on. I know many people won't agree with this but all of the people I admire in the world of CS and everyone who is a true scottsman for all intents and purposes loves dipping down to a lower level once and a while. I think the best way to learn about computer science it to program fo…

I also advocate for starting with the low-level basics, although slightly lower - logic gates. Students should start off building circuits using 74-series ICs on a breadboard, while learning about Boolean logic. If the resources to work with actual hardware aren't available, a logic simulator should suffice. This is something that I think even young kids would be comfortable with doing: simple circuits to "compute" s…

I agree 100%. I'd suggest picking up NAND to Tetris. It's a fantastic book that takes you through this. It starts you off building all of the TTL components.

Sadly the software is horrible and needs some engineering to make it approchable.

I'd love a 7400 series simulator that isn't complete crap as then I wouldn't have to resort to designging my CPU on paper. If you have recommendation please tell me.

I'd buy the components and build things up but I'm a college student and that isn't economically viable.

Edit: Link to 2 minute pitch: https://www.youtube.com/watch?v=wTl5wRDT0CU

Re: Computer Science from the Bottom Up (2013)

#44

Post by gravypod »

vvanders wrote: post #42
userbinator wrote: post #38

Earlier quoted context omitted.

I also advocate for starting with the low-level basics, although slightly lower - logic gates. Students should start off building circuits using 74-series ICs on a breadboard, while learning about Boolean logic. If the resources to work with actual hardware aren't available, a logic simulator should suffice. This is something that I think even young kids would be comfortable with doing: simple circuits to "compute" s…

I'd actually argue an FPGA/CPLD is a slightly better approach, simply because you have block memory that acts very much like "cache" and makes it abundant why system memory is so much slower. Since you have timing statistics it also makes it really easy to demonstrate pipelining and many other modern "quirks" of processors that have a large impact on performance.

The barrier to entry in the FPGA world is tooling and expression. If that hurdle is solved then I'd be all for it. It will usher a new era of electrical engineering design that is as cheap as software desgin making it practical for students to try EVERYTHING on their own.

To conduct similar experiments as I have with computer in electronics (as I'd like to do one day so I can get to the same place I am in electronics as I am in computer science) I'd need to spend thousands of dollars on chips and parts.

Re: Computer Science from the Bottom Up (2013)

#46

Post by Ar-Curunir »

gravypod wrote: post #35
Ar-Curunir wrote: post #22

Earlier quoted context omitted.

Algorithms and complexity theory are independent of any physical model of computation; they capture what it means to compute . The entire field of theoretical computer science stands as a counterexample to your comment. Computer science is not about software engineering.

An algorithm that is infinitly complex and takes infinite time is of no practical use in every day computation. Maybe in theory, in textbooks, in labcoats, but not in industry. I don't know where an uncomputable algorithm would be useful. I do know that you cannot possibly start a student out on a plane of the purely theoretical as they cannot see the value of what they are learning, they cannot understand the implic…

Nobody is talking about "infinite time" algorithms; complexity theory concerns itself with what is efficiently computable. This might not directly correspond to "real-world" efficiency, because an algorithm, while polynomial-time, but have poor constants or a huge polynomial.

However, this does not mean complexity theory is useless; it still informs us of what computers can and cannot efficiently do. It marks the limits of feasible computation.

> I don't know where an uncomputable algorithm would be useful.

Complexity theory also does not concern itself with uncomputable algorithms, so that point is irrelevant.

As you say, starting off students with abstract theory doesn't help, because they're unlikely to use it and so it won't stick. However, the same argument goes for your "bottom-up" approach; most students of computer science will not ever have to twiddle bits and manipulate assembly; knowledge of this material would thus be quickly forgotten.

My point, as stated in another comment of mine in this thread, is that it is not necessary that a "true computer scientist" know anything about low-level computer details. I suspect this holds true not only for theoreticians, but also many systems builders (like in distributed systems and such). So, having a intro course focusing on low-level details as the main component will not necessarily provide a good introduction to computer science.

Re: Computer Science from the Bottom Up (2013)

#47

Post by gravypod »

Ar-Curunir wrote: post #46
gravypod wrote: post #35

Earlier quoted context omitted.

An algorithm that is infinitly complex and takes infinite time is of no practical use in every day computation. Maybe in theory, in textbooks, in labcoats, but not in industry. I don't know where an uncomputable algorithm would be useful. I do know that you cannot possibly start a student out on a plane of the purely theoretical as they cannot see the value of what they are learning, they cannot understand the implic…

Nobody is talking about "infinite time" algorithms; complexity theory concerns itself with what is efficiently computable . This might not directly correspond to "real-world" efficiency, because an algorithm, while polynomial-time, but have poor constants or a huge polynomial. However, this does not mean complexity theory is useless; it still informs us of what computers can and cannot efficiently do. It marks the li…

> Complexity theory also does not concern itself with uncomputable algorithms, so that point is irrelevant.

I do not think this is a correct statement from what I've seen.

> As you say, starting off students with abstract theory doesn't help, because they're unlikely to use it and so it won't stick. However, the same argument goes for your "bottom-up" approach; most students of computer science will not ever have to twiddle bits and manipulate assembly; knowledge of this material would thus be quickly forgotten.

If the course is organized correctly the experiance can be magical. You're pulling the curtian on the the giant talking head. You're showing the students how everything works and you should do this directly. Like all teaching the student needs to THINK they have been the ones to discover something while in reality the teacher is supposed to have errected an artificial situation where in this was the case.

You don't start them off with bits right off the bat although that is one approche (That is extremely successful: see NAND 2 Tetris). Like I said in my other comment you state them off with a broken machine. You give them an artifical reason to continue. "If you want to get a grade you have to open up this machine and, with me coupled with some hand holding, diagnose the problem." That gives them a reason to learn about the different parts of the computer. That errects a situation where they FEEL that have found something that they weren't meant to. They've explored something when in reality it was all, as someone smarter then me once said, a "Head Fake". Get them looking at a nearer goal and they'll start dreaming of further ones.

Re: Computer Science from the Bottom Up (2013)

#48

Post by bogomipz »

junke wrote: post #10
gravypod wrote: post #5

I've been rattling this idea around in my head and, although it may sound crazy, I think C is a little high level to start an adult out on. I know many people won't agree with this but all of the people I admire in the world of CS and everyone who is a true scottsman for all intents and purposes loves dipping down to a lower level once and a while. I think the best way to learn about computer science it to program fo…

See also this presentation: Creating a language using only assembly language ( https://speakerdeck.com/nineties/creating-a-language-using-o... ).

Wow, this was really interesting. Do you know if there is any video of the presentation available? I wasn't able to find it in a quick search.

Also I love to see people using speakerdeck.com to make their presentations available, it is so much nicer and and elegant that the abomination that is slideshare.net. Cheers.

Re: Computer Science from the Bottom Up (2013)

#49

Post by bogomipz »

kazinator wrote: post #18
gravypod wrote: post #14

Earlier quoted context omitted.

Racket is much less approchable for people. I can't figure that mess out. Many people seem to find it difficult to endorse "get started and go" mentalities. The reason for N language implementations in Racket is that many LISP programmers are big fans of Domain Specific Languages (DSL) and this is also something that is taught in SICP. Edition 2 of SICP was reimplemented in Common Lisp [0] (more specifically ANSI Com…

CLISP is redistributed under the GPL, but isn't part of the GNU project. GNU project's Common Lisp implementation is a project called GCL: GNU Common Lisp, a descendant of Kyoto Common Lisp. Also, your analogy that Common Lisp to various Schemes and Clojure is like C to Java/Rust/Python is severely flawed in multiple ways.

I am curious do you have a different suggestion for a LISP implementation for working through SICP other than CLISP or would you agree this is a good choice?

Re: Computer Science from the Bottom Up (2013)

#50

Post by staticassertion »

kazinator wrote: post #34
Ar-Curunir wrote: post #20

Earlier quoted context omitted.

Computer science is not about computers; where does stuff like algorithms fit into this? What is a "true scottsman" of CS? Low level programmers? What about people that have pioneered the theory of computer science? The likes of Karp, Valiant, Cook, Blum, Vazirani, Papdimitriou, Micali, Goldwasser, Goldreich, Shamir, Rivest and etc.? I doubt these people know the inner workings of computers, but they have revolutioni…

> Increasingly today the underlying architecture, for most intents, is becoming irrelevant ... amidst cries from a handful of lunatics who insist we shouldn't be using linked lists any more because they don't use the L1 cache very well compared to arrays.

Errrr, how is this lunacy? Seems like something everyone should be aware of.
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