Comments on: Building a computer from scratch: open source computer science course http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html Brain candy for Happy Mutants Tue, 18 Jun 2013 07:08:00 +0000 hourly 1 http://wordpress.org/?v=3.4.1 By: Paul Renault http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561792 Paul Renault Sun, 21 Oct 2012 11:53:00 +0000 http://boingboing.net/?p=188655#comment-1561792  "in common use"... All the PCBs I see use SMT.  Pretty much exclusively.  ”in common use”…

All the PCBs I see use SMT.  Pretty much exclusively.

]]> By: Stephan J. Müller http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561461 Stephan J. Müller Sat, 20 Oct 2012 18:12:00 +0000 http://boingboing.net/?p=188655#comment-1561461 You don't have to solder a CPU when you are building a CPU. And it is possible with not too many logic ICs and a couple of registers (ICs containing several flip flops). They usually don't have more than 16 pins.  The problem is, if you actually want to build it, a lot of time is spent designing the circuit boards and soldering the components together. And the result after one semester is probably a 50 Hz CPU you have to program in machine language.  Building a virtual machine is a very good idea to let the students concentrate on the big picture while still knowing exactly what is going on and theoretically being able to actually build the thing.  You don’t have to solder a CPU when you are building a CPU. And it is possible with not too many logic ICs and a couple of registers (ICs containing several flip flops). They usually don’t have more than 16 pins. 

The problem is, if you actually want to build it, a lot of time is spent designing the circuit boards and soldering the components together. And the result after one semester is probably a 50 Hz CPU you have to program in machine language. 

Building a virtual machine is a very good idea to let the students concentrate on the big picture while still knowing exactly what is going on and theoretically being able to actually build the thing. 

]]> By: Sanjaya Kumar http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561453 Sanjaya Kumar Sat, 20 Oct 2012 17:55:00 +0000 http://boingboing.net/?p=188655#comment-1561453 Me too! At the exact same spot. I've never actually clapped at an online video before. As a big fan of MOOCs (coursera, edx, udacity) I'm surprised I hadn't heard of nand2tetris. I'm going to have to check it out. Thanks for the link Cory. Me too! At the exact same spot. I’ve never actually clapped at an online video before. As a big fan of MOOCs (coursera, edx, udacity) I’m surprised I hadn’t heard of nand2tetris. I’m going to have to check it out. Thanks for the link Cory.

]]> By: robcat2075 http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561368 robcat2075 Sat, 20 Oct 2012 14:47:00 +0000 http://boingboing.net/?p=188655#comment-1561368 Truly building a computer would be quite an ordeal.  Back in the Commodore AMIGA days I built an upgrade board from a kit of parts and I just about went blind soldering in the Pin Grid Array socket for the CPU and that's when they had only ~40 pins.  I'm not sure it would be humanly possible to do all the tasks that were designed to be done by robots today. Truly building a computer would be quite an ordeal.  Back in the Commodore AMIGA days I built an upgrade board from a kit of parts and I just about went blind soldering in the Pin Grid Array socket for the CPU and that’s when they had only ~40 pins.  I’m not sure it would be humanly possible to do all the tasks that were designed to be done by robots today.

]]> By: Ian Wood http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561223 Ian Wood Sat, 20 Oct 2012 06:37:00 +0000 http://boingboing.net/?p=188655#comment-1561223 Like apple pie, it starts with inventing the universe. Like apple pie, it starts with inventing the universe.

]]> By: Jonathan Badger http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561180 Jonathan Badger Sat, 20 Oct 2012 05:03:00 +0000 http://boingboing.net/?p=188655#comment-1561180 I didn't watch the video until now either (I was at work). As far as I could tell, if you hadn't read Schocken and Nisan you very well might think he was talking about real hardware. To be fair, the language that you specify things is not very different from the language that people use to program FPGAs, and those are the real future of hardware (although retro-enthusiasts do still build computers out of TTL gates) I didn’t watch the video until now either (I was at work). As far as I could tell, if you hadn’t read Schocken and Nisan you very well might think he was talking about real hardware. To be fair, the language that you specify things is not very different from the language that people use to program FPGAs, and those are the real future of hardware (although retro-enthusiasts do still build computers out of TTL gates)

]]> By: Brian Donohue http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561159 Brian Donohue Sat, 20 Oct 2012 04:14:00 +0000 http://boingboing.net/?p=188655#comment-1561159 BTW, no coincidence that such a clarion mind should have come from a family that we can thank (along, of course, with Max Brod) for our ability to read K. in English. When I was a teenager, two authors lit my lit. fire: Kafka and Dostoevsky. Those Schocken paperbacks were worn to a nub by the time I was 15. All my time since in IT, no geek experience has made me feel like those books did; I'd pick one up and without opening it would feel heart pounding, hair on spine rising, just knowing what was inside. BTW, no coincidence that such a clarion mind should have come from a family that we can thank (along, of course, with Max Brod) for our ability to read K. in English. When I was a teenager, two authors lit my lit. fire: Kafka and Dostoevsky. Those Schocken paperbacks were worn to a nub by the time I was 15. All my time since in IT, no geek experience has made me feel like those books did; I’d pick one up and without opening it would feel heart pounding, hair on spine rising, just knowing what was inside.

]]> By: SmokingHeartDesigns http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1561116 SmokingHeartDesigns Sat, 20 Oct 2012 03:13:00 +0000 http://boingboing.net/?p=188655#comment-1561116 "It's too bad that TTL gates in DIP packages aren't..." They aren't?  I use them. “It’s too bad that TTL gates in DIP packages aren’t…”

They aren’t?  I use them.

]]> By: wysinwyg http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560883 wysinwyg Fri, 19 Oct 2012 23:51:00 +0000 http://boingboing.net/?p=188655#comment-1560883  Dunno, haven't had the chance to watch it yet.  I wasn't trying to be a jerk, I was making a joke about quietly trying to clue you in so no one would notice.  I think it's an understandable mistake.  Dunno, haven’t had the chance to watch it yet.  I wasn’t trying to be a jerk, I was making a joke about quietly trying to clue you in so no one would notice.  I think it’s an understandable mistake.

]]> By: theophrastvs http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560874 theophrastvs Fri, 19 Oct 2012 23:48:00 +0000 http://boingboing.net/?p=188655#comment-1560874  thankee for elucidating on that; both of yous.  (but) was there any early indication in the above that these "PCs from scratch" are virtual only?    ("virtual @#$! ain't real @#$!" --mary chestnuttt)  thankee for elucidating on that; both of yous.  (but) was there any early indication in the above that these “PCs from scratch” are virtual only?    (“virtual @#$! ain’t real @#$!” –mary chestnuttt)

]]> By: Brian Donohue http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560848 Brian Donohue Fri, 19 Oct 2012 23:38:00 +0000 http://boingboing.net/?p=188655#comment-1560848 At the point where he talked about grading and failing, I stood up and applauded loudly. The cat delivered a startle response from across the room; otherwise, no one heard.  At the point where he talked about grading and failing, I stood up and applauded loudly. The cat delivered a startle response from across the room; otherwise, no one heard. 

]]> By: Jonathan Badger http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560832 Jonathan Badger Fri, 19 Oct 2012 23:30:00 +0000 http://boingboing.net/?p=188655#comment-1560832 Exactly. I have the authors' book. You "build" the computer theoretically, not in reality (although I imagine you could recreate the virtual computer with a FPGA). You write code that specifies the output of a "chip" based on the input. The idea is that you keep building more and more complicated circuits but understand that deep down, everything is still just gates. Exactly. I have the authors’ book. You “build” the computer theoretically, not in reality (although I imagine you could recreate the virtual computer with a FPGA). You write code that specifies the output of a “chip” based on the input. The idea is that you keep building more and more complicated circuits but understand that deep down, everything is still just gates.

]]> By: wysinwyg http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560763 wysinwyg Fri, 19 Oct 2012 22:19:00 +0000 http://boingboing.net/?p=188655#comment-1560763  Psst.  You build it on an emulator.  Psst.  You build it on an emulator.

]]> By: jondean http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560756 jondean Fri, 19 Oct 2012 22:10:00 +0000 http://boingboing.net/?p=188655#comment-1560756 From NAND gate up. From NAND gate up.

]]> By: Paul Renault http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560735 Paul Renault Fri, 19 Oct 2012 21:52:00 +0000 http://boingboing.net/?p=188655#comment-1560735 '...from scratch."?  Of course, Randall's already covered the subject...and just in the nick of time: https://www.xkcd.com/1123/ / I started my career working with and servicing equipment based on TTL gates and transistors, and eventually the equipment was based on 8-bit single-chip CPUs (such as the 8080A, the precursor to the 8086). // I agree with Schoken and Nisan.  It's too bad that TTL gates in DIP packages aren't in common use any more.  Wirewrapping rules! /// Think of NANDtoTetris as the equivalent of the way you learn math. ‘…from scratch.”?  Of course, Randall’s already covered the subject…and just in the nick of time:
https://www.xkcd.com/1123/

/ I started my career working with and servicing equipment based on TTL gates and transistors, and eventually the equipment was based on 8-bit single-chip CPUs (such as the 8080A, the precursor to the 8086).

// I agree with Schoken and Nisan.  It’s too bad that TTL gates in DIP packages aren’t in common use any more.  Wirewrapping rules!

/// Think of NANDtoTetris as the equivalent of the way you learn math.

]]> By: theophrastvs http://boingboing.net/2012/10/19/building-a-computer-from-scrat.html#comment-1560723 theophrastvs Fri, 19 Oct 2012 21:40:00 +0000 http://boingboing.net/?p=188655#comment-1560723 "PCs from <i>scratch</i>"  ??  i couldn't readily (first 5 minutes of biographic video) figure out at what level "scratch" meant. perhaps somewhere between mining the silicon and being handed a motherboard?  (because it can't be much of an achievement if any idiot like me who's typing this on a computer "assembled from scratch" started with a motherboard)  i'll assume the students were given nothing more pre-made than a (ARM) CPU..? “PCs from scratch“  ??  i couldn’t readily (first 5 minutes of biographic video) figure out at what level “scratch” meant. perhaps somewhere between mining the silicon and being handed a motherboard?  (because it can’t be much of an achievement if any idiot like me who’s typing this on a computer “assembled from scratch” started with a motherboard)  i’ll assume the students were given nothing more pre-made than a (ARM) CPU..?

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