a golden age of Amiga

[HenryCase]

@Tripitaka

We thought it was a terrible waste as the hardware encoder was now redundant and had cost a whopping amount of cash. Anyway, we got into talking about what a shame it was that we couldn't re-write the damn chip to do something more useful.

I agree, it's a shame when dedicated hardware no longer adds value to a system. This is something reconfigurable computing aims to do away with.

@bloodline

It's really fun to think about the technology, and what you could put together in an interesting way... But really when building a product, you need to find a core, basic need that is unforfilled and then try and meet that need in the simplest cheapest way...

Make no mistake about it, I'm not going for a single niche here, I'm going for general purpose computing. Let's go through the benefits I listed before:

Increased efficiency - Important where performance is key. Whatever tasks need high performance computing could benefit. If you want a single example, think of physics simulations.

Enhanced extensibility (both at the hardware and software level) - Important where you have tasks you have specific niche requirements. This is important in markets that are just beginning, or are too small for large investment. For an example of a market where extensibility could be a benefit, think of home automation.

Easier maintainability - This is just common sense. By keeping the core operating system compact and easier to understand, you increase the number of people that are adept at reasoning about its function. The more accurately that people can build a mental model of how something works, the more adept they will be at using, fixing and enhancing it. Benefits will be felt in all industries where it is used.

(Potentially) lower power draw - The obvious answer is this is important for mobile devices, but it's important for much more than that, for example power draw in servers is also a big concern. Memristor-based FPGAs have a number of ways to reduce power draw. For example, with modern CPUs you hear people talking about 'dark silicon'. Dark silicon is where you have unused sections of your processor, because it's getting increasingly hard to send power the whole chip all of the time. We can use this to our advantage; by switching off the unused chip real estate through use of memristor switches, you can optimise your device for low power draw. Then, when more power is available, you switch the extra circuitry on again.

(Potentially) lower cost - If I really have to explain why this will help this succeed, I really don't know what to say!

With all that said, there are markets I think will adopt earlier than others. The obvious places to look is where FPGAs are already in use, i.e. in embedded systems. Embedded systems are specialised enough that you don't need a large, expansive software ecosystem to build what you need. Plus, the engineers building embedded systems are more attuned to choosing hardware based on its actual merits rather than from any emotional ties.

As the software ecosystem develops, the system will become attractive to more and more markets. However, I'm not going to waste my time imagining what these markets will be, I am confident that people will see the benefits, just need the system to be built so those benefits can be realised. Hope that answers your question.

@Mrs Beanbag

Currently (as I understand it at least) the device has to be turned off, loaded with a design, and then turned on again.

I quoted this particular text, as I think it shows I've confused you by using the term FPGA. The FPGAs that are possible with memristors do not need to follow the same restrictions that traditional FPGA designs have.

For the conversation to move forward, I think it is absolutely vital that you understand the benefits that memristors could bring.

Firstly, it can make FPGAs reprogrammable on-the fly.

Secondly, it can make FPGAs more efficient.

Thirdly, memristors could potentially replace RAM, as well as long term storage, and processing. Essentially you can get all three in one chip.

Now, I hinted before that there are some issues with memristors replacing RAM at the moment, but considering how new memristors are, I anticipate memristors will be used in RAM in the future, once these challenges are overcome.

If you'd like a shorter introduction to the memristor video I posted before, please watch this video, it's only 6 minutes long, and should help you understand how memristors can change the structure of FPGAs:
http://www.youtube.com/watch?v=rvA5r4LtVnc

@all
Welcome to field any more questions. Also, welcome to hear more feedback, positive or negative. Thanks.

[HenryCase]

I need to get my head round this "imaginary current" that you see in passive circuit analysis

I'm sorry, what imaginary current are you referring to?

But, what I propose with completely reconfigurable FPGAs is already possible with existing technologies.  In fact now I think about it I reckon it's possible to do it in an FPGA.  META.

The function of present day FPGA devices is fixed at boot time, how do you intend to get around this? You may be able to get around it using multiple fast booting FPGAs (see article here: http://electronicdesign.com/article/digital/fpgas-boot-in-a-flash15649.aspx ), is that what you intended?

[HenryCase]

a understand what your saying on very basic level what is diffrence between fpg
 the simple pic control chips i seen my friend program i know these have very limited storage but seems you can do alot with less , which what your saying .
apart from elagance of working with this whats the practice benifets of this
lower power use.
and chould you use the advanced c who is this diffrent ot a fpg i kinda dont understand what fpg is i know its a progamed aray how does it diffrent from a cpu ?
its been itresting read keep it up

I rememby freind who was into computers before amiga came out he had amstrad 128
talking about cpus and how many bits make up a byte it stayed with me all this time
Some pople just make this stuff great to learn about , kevin cameron guy on engine design in the same vein , makes complicated eem simple enough for you to want learn more and more

Thank you for your interest and support actung_bab.

With regards to the practical benefits, there are many areas of the system we haven't discussed yet, but the main point I've tried to get across so far is the benefits that come from blurring the lines between hardware and software.

If you'd like to know about the benefits of low power use in particular, as stated before power usage is a concern across the whole computing industry. With regards to the data on lower power draw, we'll have to wait until the FPGAs are built (which is why I said 'potentially' lower power draw), however to give you a ballpark figure, the estimates I've seen say we're looking at 1.5 to 2 times less power usage compared to equivalent transistor-based circuitry.

If you'd like to learn more about memristors, here are two articles worth looking at. One is less technical, the other is more technical. The less technical one:
http://highscalability.com/blog/2010/5/5/how-will-memristors-change-everything.html

The more technical one:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fcadlab.cs.ucla.edu%2F~cong%2Fpapers%2Fnano11.pdf&ei=lcc0T9mZBaGh0QXP9-i7Ag&usg=AFQjCNHDb6_yA_Pn6nx6ZEBuYU8MiKI-DA

Hope this has been useful in broadening your understanding. Feel free to ask any further questions you have about this.

[HenryCase]

Well we all know V=IR, right?  Ohm's law.  Well if you let R be a complex number (we write it as Z instead and call it "impedance" rather than resistance) you can model impedance and capacitance as well.  The voltage and current ends up complex as well, of course, which makes no sense, but nevertheless it works.  I don't know what the "impedance" of a memristor would be, I can only surmise that this simple "electronic theory hack" isn't quite up to the task of representing it.  The problem is that it's quite ad hoc, as far as I can tell it's not properly derived from fundamental laws, it's just made up and used because it works.

Let me put it to you like this, do you understand how memristors work at the molecular level? Please watch that 6 minute video I posted before:
http://www.youtube.com/watch?v=rvA5r4LtVnc

There's nothing mysterious about this, all that is happening is electrons can be made to move between two different materials based on the direction of the current applied over them. This device happens to exhibit the properties described for a memristor, so they unsurprisingly called it a memristor. In simple terms, a memristor is a device where the flux and charge affect each other.

Whether our FPGA works on memristors or not, we need a design.  You can't just throw memristors at it and magically it becomes reconfigurable on the fly.  

Oh dear. I'm not throwing memristors at FPGAs and 'magically' expecting it to be reconfigurable, I know for a fact that memristors will make FPGA devices reconfigurable, because THE PEOPLE THAT DISCOVERED THE MEMRISTOR ARE SAYING THE SAME THING. Please see here:
http://pubs.acs.org/doi/abs/10.1021/nl901874j

Please stop trying to shoehorn your existing knowledge into this new model, and please try to see that use of memristors can alter the architectural possibilities for FPGAs. Thanks.

[HenryCase]

No I don't, and I watched the video and I still don't.  Solid state physics was never my best subject.

Ok well, whatever.  It's still a device that doesn't fit into the generalised impedance model, which I'm saying is inadequate and makes no sense because it was made up ad-hoc to describe only what we knew already.  I'm saying that a better theory might predict even more different types of passive components.

I'm all up for entertaining alternative theories, but would suggest you'll have a better time of forming successful theories about what's happening with these devices if you understand how the electrons are moving in this device. Let's start with the basics: what makes a material positively or negatively electrically charged?

Memristors won't make FPGAs reconfigurable, or anything else.  Well maybe it will make them smaller.  It's a switch.  Like the guy is saying, you can replace ten transistors with one memristor (I'll take his word for it).  Maybe that opens up all sorts of new possibilities, but a possibility isn't a device.  You still have to DESIGN a dynamically reconfigurable FPGA, whether you use memristors or not.  No matter what components you use, even if it's alien technology that's a million years in advance of our own, how to design an "FPGA-like device" that you can reconfigure while it's running is still an architectural challenge.  And I'm saying it's possible already, even without memristors.  (With memristors, it would be even better, I guess.)

I can't read the full text of that article you posted, but the abstract doesn't mention anything about dynamic reconfiguration.  "Reconfigurable logic" could describe present FPGAs.

Again, you persist by insisting memristors won't make FPGAs reconfigurable. I don't really know how bluntly I should tell you that you're wrong before you'll listen. Take a look at this:
http://www.pnas.org/content/106/6/1699.full

I'll even quote you the relevant text to save you reading the whole thing:

A completely different type of demonstration is the conditional programming of a memristor by the integrated circuit in which it resides, which illustrates a key enabler for a reconfigurable architecture (21, 22, 25), memristor based logic (24) or an adaptive (or “synaptic”) circuit that is able to learn (26, 27). Based on a portion of the hybrid circuit described above, we showed that the output voltage from an operation could be used to reprogram a memristor inside the nanocrossbar array, which could have been used as memory, an electronic analog of a synapse or simply interconnect, to have a new function.

Do you believe me now? The reason I'm ignoring your hack to try to implement reconfigurable FPGAs using what we have now is that it's sub-optimal compared to memristor-based devices. I hope you agree.

[HenryCase]

I don't know whether you're leading me or patronising me here.  Why, it's electrons, of course.  I'm not trying to form a theory of "these devices" in particular.  I know there are deeper theories in solid state physics to account for many different things, they are a little over my head to be honest with you.  I don't want to have to worry about individual electrons.  All I want to get my head round for now is what the imaginary components of current and voltage physically represent.  Usually the textbooks just shrug it off and tell you the imaginary components don't really mean anything physical at all, it's just some maths to sweep under the rug at the end of your calculations.  Which makes no sense.  It's all a bit fudged.  If I could just work out how to derive these things from Maxwell's Equations...

I agree with you, I think it's important to understand how voltage, current and other electric phenomena work at a fundamental level, and I don't like it when learning sources dismiss an understanding at this level as unnecessary.

The best analogy for voltage and current I can think of off the top of my head is the rain: if you think of rain as a circuit the change in the circuit depends on how much water vapour is held in higher elevation (clouds), and the rate at which rain drops fall. Voltage can be thought of as potential difference in energy, and current can be thought of as the rate at which the potential energy is used. So for rainclouds, the voltage is the height and amount of water vapour in clouds, and the current is the amount of water that falls to the ground at a point in time.

In electric circuits, electrons do all the work. Current and voltage are just two ways of describing the state of the electrons in the circuit.

This is the best introduction to electronics I've found so far. If you're already familiar with Maxwell's equations it may be covering ground you are already familiar with, but I'll share it just in case:
http://lcamtuf.coredump.cx/electronics/

In other words, the same thing, but better.  Memristors have other more specific advantages, from what I gather, if you want to build something like a hardware neural network.  Which I don't, personally.  So I think we might be talking at crossed purposes here.

A chip that can implement a neural network needs to be able to change its own structure, otherwise it wouldn't be able to 'learn'. It's a specific application of a run-time configurable device.

Well of course I believe you, I never doubted that it's possible to make a self-reconfigurable device.  But you would still have to design one.

I don't intend to design one. I intend to buy one after they're manufactured. I don't even need to design my own PCB, a reference platform should suffice for a proof of concept. I've got plenty of research to do before I have a chance of implementing the real device, so this delay in availability is not a problem IMO.

[HenryCase]

Don't believe the hype. People in the microelectronics world are already searching for the Holly grail, e.g. the universal memory a long time. The previous candidate was MRAM or magnetic RAM but did not follow on the hype.
Maybe memristors is the next Holly grail but I find the chance small. Problem is that memristors are a kind of resistive memories. They depend on the change of the solid state of materials to get a change in resistance. I think this will always be more involved then putting a few electrons on a small capacitor which is the base for DRAM.
More less hype driven info is here

greets,
Staf.

So, to paraphrase your main argument, you're saying "Because this earlier technology didn't live up to it's promise, I doubt this newer technology will live up to its promise either". Forgive me if I take such a notion with a grain of salt, I prefer to assess each individual technology on its own merits.

Besides, I never used the term 'holy grail', you chose to use this label, it's not my fault if you choose to use such inaccurate labels. The point I've been trying to get across is that memristors can be very beneficial for improving FPGAs, which will be beneficial for the computer system I'm proposing. I've hinted at a couple of times that a memristor-based RAM wouldn't be competitive with DRAM yet, but only mentioned this as an aside, as it's the performance improvements being brought to FPGAs that is relevant to this discussion.

However, as you brought it up, let's take a look at the challenges that memristors face to be a viable replacement for DRAM. The two main issues are:

1. Memristor-based RAM would currently be slower than DRAM.
2. Need to increase the read-write lifecycles that can be achieved with memristors before it can replace DRAM.

Let's put some approximate numbers in place for the points above so we know the level of challenges were looking at. When memristors were first discovered, there was talk that they were approximately x10 slower than DRAM. With regards to read-write lifecycles, current memristors have been show to have approximately 1 million read-write lifecycles.

It's worth bearing in mind that memristors are a new technology, whereas DRAM is a mature technology. However, since the discovery of memristors there have a lot of companies investing in R&D on this technology. Case in point, the speed. Back in 2008 we were looking at x10 slower performance. In 2012, we're now looking at equivalent write performance. See here:
http://www.bbc.co.uk/news/technology-16725529

Recently, the Japanese memory manufacturer Elpida announced it had produced a prototype ReRAM memory with speeds comparable to DRAM.

"Its most attractive feature is that it can read/write data at high speeds using little voltage," Elpida said in a press release.

"It has a write speed of 10 nanoseconds, about the same as DRAM.

So in some ways, the speed gap issue has been addressed. The remaining issue then is the read-write cycles. I anticipate the companies working on memristor-tech for non-volatile storage will invest resources in improving the hardiness of memristor devices, and these benefits should eventually reach a tipping point where memristors become 'good enough' to replace DRAM. For example, if the read-write lifecycle improves to the point where memristor-based RAM would last 5 years in continuous use, this should be good enough performance to enable widespread memristor-based RAM usage. Also, the improved capacity of memristor devices may help this change happen sooner. If a 32GB memristor device was a lower cost than a 2GB DRAM, you could sell the memristor device as a 2GB DRAM replacement and use the massive redundancy to your advantage (effectively obtaining 16 million read-write cycles with current memristor performance using wear levelling).

With all that said, memristor-based RAM is off topic for what is being proposed, it's the improvements to FPGAs that matter here. I hope we can get back on topic now.

[HenryCase]

look here
Staf.

Interesting, thanks for the link. Could you help further by advising on the lowest cost FPGA that offers partial reconfiguration?

[HenryCase]

I'll read that later, it may be "concise" but it's still quite a lot of reading!

Yes, it is quite a bit to read. Hope it's useful to you.

Neural Networks are useful and interesting for all kinds of reasons, but it's not the problem I'm trying to solve.

Neural networks aren't the problem I'm trying to solve either. However, a chip that can model neural networks without 'software' in the traditional sense is one that is reprogrammable, and it's this reprogrammability that I was trying to highlight.  

Anyway, I'll stop going on about memristors now, all I hope is that I've done some good in raising awareness of what's incoming in FPGA tech.

Well here's the rub.  But I do intend to design one... well, I intend to idly speculate about one... but if I could put my design on a standard FPGA I could put it on a memristor-based FPGA as well.

Fair play to you! Of course I'm pleased to hear of your intentions, as like you say it'll allow you to get the ball rolling quicker.

The problems that I'm trying to solve are architectural, rather than electronic.  We know it's possible for a cell to reconfigure itself, the problems are:
1) how does a cell know when to reconfigure itself?
2) how does it know what to reconfigure itself as?
3) how does the relevant data get there?

I'm thinking of a scheme based on systolic arrays.

To me, the answers to those three problems are found in the OS design, which is one subject we haven't talked much about yet. To date, I've not worked on the low level issues you're discussing, but would be interested in exploring the design possibilities with you. Could you tell me what systolic arrays are?

Thought you might be interested in Tabula FPGAs, Mrs Beanbag. Is this hardware in line with what you're looking for?
http://www.popsci.com/technology/article/2011-04/reprogrammable-chips-could-allow-you-update-your-hardware-just-software

At the moment I'm working through the design of the file system. It's still early days, I'm currently working through the implications of taking Plan 9's 'everything is a file' notion (to people who know about this approach from Unix/Linux, Plan 9 takes this approach further), and morphing it into 'everything is an object'. The plan for this is to make every component in the OS as reusable as possible. So at one end of the system we'll be blurring the lines between hardware and software, and at the other end of the system we'll be blurring the lines between the OS and the applications. If you're interested to learn more about the plans for the OS I'm talking about, please feel free to ask me.

[HenryCase]

Sadly it's the same story, "this is Ohm's law.  It just is."  It's empirical, there isn't really a derivation.

Sorry it wasn't as useful to you as I'd hoped.

Now that's interesting, I guess it's kind of similar in principle (to switch cores in and out) but my idea is to be able to fetch them from off chip, this has a certain number in reserve that it can switch in and out.  I could use that technique as well, I guess.

Yes, the Tilera approach is definitely interesting. It also seems to be reasonably affordable, judging from this video:
http://www.youtube.com/watch?v=lFghLrpPy6M
"Tad over $100 in 2000 lot quantities". Of course, the price will be higher for single units. Sadly the devboard is too pricey for me:
http://dangerousprototypes.com/2011/04/27/what-does-a-7500-dev-kit-look-like/

You know this sounds very much like my own idea for an OS from several years back.

Cool. What ideas did you have for your OS?

[HenryCase]

Unfortunately I am no expert on PCB board design etc; I learned about partial reconfiguration from a presentation from a Xilinx guy at my work. I'm afraid you'll have to go through the spec sheets of the Xilinx.

Okay, thanks.

[HenryCase]

Maybe I am biased; I am already working for more than 15 years in the microelectronics research and development institute imec.

I'm not going to derail this thread further by countering your full post (as I have more to discuss than just memristors), but would like to point out that someone at your company thinks memristor-based RAM is worth researching:
http://www2.imec.be/be_en/research/sub-22nm-cmos.html

Advanced memory: DRAM, floating gate, resistive RAM

I take it you work in a different department?

[HenryCase]

I can only quote from my previous post:
"My personal opinion is that ReRAM is a possible good candidate for the next non-volatile memory, but then only if the prediction of the scaling stop for NAND flash is finally becoming reality. I don't think it will replace DRAM."
I want to add that probably certain characteristics of ReRAM will find their niche market even if it won't replace FLASH NVM.

At the end of the day, neither of our opinions is going to change the outcome of how the tech takes off, so let's let the tech stand on its own merits, and bring this conversation back to that which we can have an influence on i.e. the next evolution of personal computing. Do you have any opinions on what has been discussed so far (other than the memristor stuff)?

[HenryCase]

@Thorham
What's being discussed is not necessarily a golden age of computers called Amigas, but a new golden age of personal computing, the next evolutionary step from what we had before if you will.

If you weren't attracted to the revolutionary platforms of the past, then you won't be interested in any new revolutions that come along, that much is true, but for people who don't have that ambition they can settle for nostalgia instead.

[HenryCase]

@Mrs Beanbag
The thing about computing, is that as the power increases and algorithms evolve, the tasks you'd class as too impractical to consider before become much more accessible. It's hard to guess what level of performance improvement is going to be achieved, so it's also hard to predict the tasks that will enter the realms of practicality. Therefore, you often find technology evolves with a 'build first, think of the applications later' approach.

Going back to your exploration of Ohm's Law, found this thread, thought you might find it useful:
http://www.physicsforums.com/showthread.php?t=179056