9 ms·

RTX2010 – Radiation-hardened stack machine microprocessor

156 points by lelf 12y ago

lelf 12y ago
Philae is controlled by 2 RTX2010 CPUs (hot red), further 8 control the Experiments. 13 CPUs (10* RTX2010, 1* ADSP-21020, 2* 80C3x) in total. © https://twitter.com/philae2014/status/427842417920712704 https://twitter.com/philae2014/status/427842417920712704
- userbinator 12y ago
  > 80C3x An 8051-family microcontroller, the CPU architecture that's found almost everywhere - including space. I wonder if they're running Forth too, as this old discussion I found also mentions 80C32 and RTX2010 together with Forth: https://groups.google.com/d/topic/comp.lang.forth/7PK44n68I_4 https://groups.google.com/d/topic/comp.lang.forth/7PK44n68I_...
  - analog31 12y ago
    The 8052AH-BASIC is better known because of a Byte Magazine article, but there was also a commercially available 8051 variant that was mask programmed with a built in Forth interpreter. I've never seen one.
- keenerd 12y ago
  For future archaeologists wondering why everyone is talking about Philae, the title of this thread used to be to the effect of "The rad-hard CPU used in Philae".
lucaspiller 12y ago
Tech specs are available on the manufacturer's site: http://www.intersil.com/en/products/space-and-harsh-environment/rad-hard-digital/rh-microprocessors-and-peripherals/HS-RTX2010RH.html#0.html http://www.intersil.com/en/products/space-and-harsh-environm...
tinco 12y ago
I wonder how hard it is to create a radiation hardened CPU. Is the premise that radiation can flip bits in the on-die cache and registers? would simply making those redundant be a solution? Or could a single flash of radiation invalidate all memory on the device?
- Sanddancer 12y ago
  There's all sorts of problems you have to deal with. Memory flipping is one of the most visible, but that radiation also will damage the lattice of the processor, making some transistors harder to flip on, and some much easier to flip on, leading to transient glitches, etc. Redundancy's definitely one solution, which is one reason why spacecraft tend to have multiple processors and/or processors with redundant logic pipelines. They also tend to use different substrates that are harder for cosmic rays to effect, different, more expensive, casings that offer more shielding, and also larger, older, more vetted processes. For example, this chip is uses a 1 micron process, which is a lot bigger than the process used in current cpus, which means that there's a lot more mass in the transistors to soak the effects of radiation, making it harder to cause damage.
  - Osmium 12y ago
    Or we can use alternative semiconductors that are more radiation-resistant. One of many reasons why materials discovery is still very important even if initial chips will never match the performance of silicon.
    - wlievens 12y ago
      Wouldn't work for all applications, tough, if I'm not mistaken, as you specifically need Silicon for imaging chips (CCD/CMOS). Or is that nonsense?
      - Someone 12y ago
        Why would you need silicon for that? Even if it were the only process we use now (which it isn't. As a simple example, Germanium-based photo diodes do exist), materials research could conceivably produce other materials that work, too. There are even more exotic examples to think of. Eyes turn light into electricity without (AFAIK) Silicon. Maybe part of that physics/chemistry can be practically used elsewhere?
jng 12y ago
I'm sure Mr. Moore feels vindicated that the fruits of his design work have powered humanity's first comet landing ever. Still, it's telling of the industry's regard for Forth that the manufacturer itself manages to misspell the language as "Fourth" in the chip's official product page.
- cbd1984 12y ago
  To be fair, Moore originally wanted the language to be called "Fourth": > The file holding the interpreter was labeled FORTH, for 4th (next) generation software - but the operating system restricted file names to 5 characters. http://www.colorforth.com/HOPL.html http://www.colorforth.com/HOPL.html It was the OS for the IBM 1130: http://en.wikipedia.org/wiki/IBM_1130 http://en.wikipedia.org/wiki/IBM_1130 Because it was the cheapest computer IBM had at the time, it got used by a lot of young pioneers in their salad days.
- lbruder 12y ago
  Well, it was the original name Forth was going to have. Just that the OS it was built on allowed only five character file names...
jacquesm 12y ago
Hah, an old friend. A company I worked with had a Novix in 1986/1987 for prototyping purposes (early days number plate recognition system). Before we got it we had to sign an unreasonable amount of paper. Rumor had it this is the chip powering the Tomahawk cruisemissile.
- abecedarius 12y ago
  Brought a smile to my face too: I had a summer job in 1986 at FORTH, Inc., and spent some quality time with my officemate's cmForth manual. (cmForth was Chuck Moore's new Forth dialect for the Novix. IIRC the manual said the multiply-step instruction didn't quite work and gave a software workaround.)
- Create 12y ago
  Raytheon refurbish...
jesrui 12y ago
Another microprocessor able to execute Forth natively is the b16, from one of the original authors of Gforth. http://bernd-paysan.de/b16.html http://bernd-paysan.de/b16.html
- ryanmk 12y ago
  There's also GreenArrays GA144, which has 144 forth machines on a single microprocessor. http://www.greenarraychips.com/ http://www.greenarraychips.com/
programmer_dude 12y ago
Can someone point to resources comparing stack machines and register based machines? The RTX2010 technical documentation talks about all the advantages of a stack machine but doesn't say anything about its shortcomings.
- wlievens 12y ago
  Optimal register allocation is an NP-complete problem. By doing away with it, you don't need to allocate registers. How that compares on a practical level, I have no idea. But it's one of the reasons the JVM has a stack-based model and no registers: it makes writing compilers for JVM byte code a lot easier.
  - s800 12y ago
    Interesting. I agree with your statement regarding it being an NP-complete problem, as intuitively it seems that way, but do you have a reference by chance? Thanks!
    - jlarocco 12y ago
      I can't find the original paper, but this almost seems more relevant. http://research.ihost.com/lcpc06/final/7/7_Paper.pdf http://research.ihost.com/lcpc06/final/7/7_Paper.pdf Actually, here's the original for sale, but the abstract doesn't explicitly mention being NP-complete. http://www.sciencedirect.com/science/article/pii/0096055181900485 http://www.sciencedirect.com/science/article/pii/00960551819...
    - CHY872 12y ago
      Ok, so we can view register allocation as being a case of graph colouring; create a graph where the nodes are your 'virtual registers' and there's an edge between two nodes if those registers are both live at the same time. Then we can run on n registers iff we can colour the graph with n colours. This is one of the first identified NP-complete problems. https://en.wikipedia.org/wiki/Graph_coloring https://en.wikipedia.org/wiki/Graph_coloring
  - 12y ago
mud_dauber 12y ago
How cool - I joined Harris after grad school expressly to work on RTX architecture issues. (Previously I was a Forth developer.) Nice to see this neat-but-underappreciated architecture in the news.
- naland 12y ago
  >Nice to see this neat-but-underappreciated architecture in the news. It's already appreciated. Let me recall here the 'scientist' character (A&B Srugatsky) who explains the World as a huge inertial mass to the good or evil in the same. Tertium non datur it is a principle of our mind sometimes used in computers.
  - naland 12y ago
    edit: Strugatsky. hi ±HN.
    - abecedarius 12y ago
      I believe the downvotes came from not seeing any relevance to your comment -- I don't see it myself.
  - jacquesm 12y ago
    What does Russian SF have to do with the Forth high level machine?
imrehg 12y ago
Listed but unfortunately not stocked: http://www.mouser.tw/Search/Refine.aspx?Keyword=RTX2010 http://www.mouser.tw/Search/Refine.aspx?Keyword=RTX2010
- kens 12y ago
  I looked on Alibaba and Shenzhen suppliers have the HS9-RTX-2010-RH for sale at 10 cents a chip, able to supply up to 100,000 chips per month. How do they do this? They're lying. Various Alibaba vendors list literally every part number they can find as something they are selling. If someone wants it, then they see if they can actually get it. In any case, the real price for the RX2010 was between $1000 and $10,000 according to this thread I found from 1999: http://www.strangegizmo.com/forth/MISC/msg01281.html http://www.strangegizmo.com/forth/MISC/msg01281.html
  - mud_dauber 12y ago
    Of course they are. The last place I'd go for reputable semiconductor suppliers is Alibaba. The LAST.
- nraynaud 12y ago
  it's quite strange that there is not backlash against those manufacturers that don't make their parts or their datasheet available. They are just a pain in the butt and they drive our buying power down.
SixSigma 12y ago
A very closely related processor, the RTX2000, is described in detail in Koopman's book "Stack Computers: the new wave" http://users.ece.cmu.edu/~koopman/stack_computers/index.html http://users.ece.cmu.edu/~koopman/stack_computers/index.html The RTX2010 has had its own wikipedia entry too since 2008 : http://en.wikipedia.org/wiki/RTX2010 http://en.wikipedia.org/wiki/RTX2010
samatman 12y ago
The yearly Forth Day meeting is happening right now, and Chuck Moore (inventor of Forth, designer of the RTX2010) is going to give his annual fireside chat in a matter of hours. I'm honored to be in attendance. So if HN has any questions, this is a good time to ask them. The hangout is here: https://plus.google.com/u/0/115269917987589859757/posts https://plus.google.com/u/0/115269917987589859757/posts
- tailrecursion 12y ago
  Sam, Chuck designed the Novix but the Harris RTX 2000, which is very similar, was designed by others. These are 16-bit chips (the Novix addressed 128 KB) that use dedicated stack memories, that's 3 ports to memory total. The RTX puts the stacks on chip. The nice thing about these CPUs is they can do stack, alu, and return in parallel, interrupts are cheap, timings are predictable, and programming model is nice if you like Forth. One disadvantage of the design is that clock rate is limited. RAM fetch and instruction processing have to fit between pulses meaning RAM has to be approx twice as fast as clock.

156 points by lelf 12y ago

lelf 12y ago

Philae is controlled by 2 RTX2010 CPUs (hot red), further 8 control the Experiments. 13 CPUs (10* RTX2010, 1* ADSP-21020, 2* 80C3x) in total. © https://twitter.com/philae2014/status/427842417920712704 https://twitter.com/philae2014/status/427842417920712704

userbinator 12y ago
> 80C3x An 8051-family microcontroller, the CPU architecture that's found almost everywhere - including space. I wonder if they're running Forth too, as this old discussion I found also mentions 80C32 and RTX2010 together with Forth: https://groups.google.com/d/topic/comp.lang.forth/7PK44n68I_4 https://groups.google.com/d/topic/comp.lang.forth/7PK44n68I_...
- analog31 12y ago
  The 8052AH-BASIC is better known because of a Byte Magazine article, but there was also a commercially available 8051 variant that was mask programmed with a built in Forth interpreter. I've never seen one.
keenerd 12y ago
For future archaeologists wondering why everyone is talking about Philae, the title of this thread used to be to the effect of "The rad-hard CPU used in Philae".

lucaspiller 12y ago

Tech specs are available on the manufacturer's site: http://www.intersil.com/en/products/space-and-harsh-environment/rad-hard-digital/rh-microprocessors-and-peripherals/HS-RTX2010RH.html#0.html http://www.intersil.com/en/products/space-and-harsh-environm...

tinco 12y ago

I wonder how hard it is to create a radiation hardened CPU. Is the premise that radiation can flip bits in the on-die cache and registers? would simply making those redundant be a solution? Or could a single flash of radiation invalidate all memory on the device?

Sanddancer 12y ago
There's all sorts of problems you have to deal with. Memory flipping is one of the most visible, but that radiation also will damage the lattice of the processor, making some transistors harder to flip on, and some much easier to flip on, leading to transient glitches, etc. Redundancy's definitely one solution, which is one reason why spacecraft tend to have multiple processors and/or processors with redundant logic pipelines. They also tend to use different substrates that are harder for cosmic rays to effect, different, more expensive, casings that offer more shielding, and also larger, older, more vetted processes. For example, this chip is uses a 1 micron process, which is a lot bigger than the process used in current cpus, which means that there's a lot more mass in the transistors to soak the effects of radiation, making it harder to cause damage.
- Osmium 12y ago
  Or we can use alternative semiconductors that are more radiation-resistant. One of many reasons why materials discovery is still very important even if initial chips will never match the performance of silicon.
  - wlievens 12y ago
    Wouldn't work for all applications, tough, if I'm not mistaken, as you specifically need Silicon for imaging chips (CCD/CMOS). Or is that nonsense?
    - Someone 12y ago
      Why would you need silicon for that? Even if it were the only process we use now (which it isn't. As a simple example, Germanium-based photo diodes do exist), materials research could conceivably produce other materials that work, too. There are even more exotic examples to think of. Eyes turn light into electricity without (AFAIK) Silicon. Maybe part of that physics/chemistry can be practically used elsewhere?

jng 12y ago

I'm sure Mr. Moore feels vindicated that the fruits of his design work have powered humanity's first comet landing ever. Still, it's telling of the industry's regard for Forth that the manufacturer itself manages to misspell the language as "Fourth" in the chip's official product page.

cbd1984 12y ago
To be fair, Moore originally wanted the language to be called "Fourth": > The file holding the interpreter was labeled FORTH, for 4th (next) generation software - but the operating system restricted file names to 5 characters. http://www.colorforth.com/HOPL.html http://www.colorforth.com/HOPL.html It was the OS for the IBM 1130: http://en.wikipedia.org/wiki/IBM_1130 http://en.wikipedia.org/wiki/IBM_1130 Because it was the cheapest computer IBM had at the time, it got used by a lot of young pioneers in their salad days.
lbruder 12y ago
Well, it was the original name Forth was going to have. Just that the OS it was built on allowed only five character file names...

jacquesm 12y ago

Hah, an old friend. A company I worked with had a Novix in 1986/1987 for prototyping purposes (early days number plate recognition system). Before we got it we had to sign an unreasonable amount of paper. Rumor had it this is the chip powering the Tomahawk cruisemissile.

abecedarius 12y ago
Brought a smile to my face too: I had a summer job in 1986 at FORTH, Inc., and spent some quality time with my officemate's cmForth manual. (cmForth was Chuck Moore's new Forth dialect for the Novix. IIRC the manual said the multiply-step instruction didn't quite work and gave a software workaround.)
Create 12y ago
Raytheon refurbish...

jesrui 12y ago

Another microprocessor able to execute Forth natively is the b16, from one of the original authors of Gforth. http://bernd-paysan.de/b16.html http://bernd-paysan.de/b16.html

ryanmk 12y ago
There's also GreenArrays GA144, which has 144 forth machines on a single microprocessor. http://www.greenarraychips.com/ http://www.greenarraychips.com/

programmer_dude 12y ago

Can someone point to resources comparing stack machines and register based machines? The RTX2010 technical documentation talks about all the advantages of a stack machine but doesn't say anything about its shortcomings.

wlievens 12y ago
Optimal register allocation is an NP-complete problem. By doing away with it, you don't need to allocate registers. How that compares on a practical level, I have no idea. But it's one of the reasons the JVM has a stack-based model and no registers: it makes writing compilers for JVM byte code a lot easier.
- s800 12y ago
  Interesting. I agree with your statement regarding it being an NP-complete problem, as intuitively it seems that way, but do you have a reference by chance? Thanks!
  - jlarocco 12y ago
    I can't find the original paper, but this almost seems more relevant. http://research.ihost.com/lcpc06/final/7/7_Paper.pdf http://research.ihost.com/lcpc06/final/7/7_Paper.pdf Actually, here's the original for sale, but the abstract doesn't explicitly mention being NP-complete. http://www.sciencedirect.com/science/article/pii/0096055181900485 http://www.sciencedirect.com/science/article/pii/00960551819...
  - CHY872 12y ago
    Ok, so we can view register allocation as being a case of graph colouring; create a graph where the nodes are your 'virtual registers' and there's an edge between two nodes if those registers are both live at the same time. Then we can run on n registers iff we can colour the graph with n colours. This is one of the first identified NP-complete problems. https://en.wikipedia.org/wiki/Graph_coloring https://en.wikipedia.org/wiki/Graph_coloring
- 12y ago

mud_dauber 12y ago

How cool - I joined Harris after grad school expressly to work on RTX architecture issues. (Previously I was a Forth developer.) Nice to see this neat-but-underappreciated architecture in the news.

naland 12y ago
>Nice to see this neat-but-underappreciated architecture in the news. It's already appreciated. Let me recall here the 'scientist' character (A&B Srugatsky) who explains the World as a huge inertial mass to the good or evil in the same. Tertium non datur it is a principle of our mind sometimes used in computers.
- naland 12y ago
  edit: Strugatsky. hi ±HN.
  - abecedarius 12y ago
    I believe the downvotes came from not seeing any relevance to your comment -- I don't see it myself.
- jacquesm 12y ago
  What does Russian SF have to do with the Forth high level machine?

imrehg 12y ago

Listed but unfortunately not stocked: http://www.mouser.tw/Search/Refine.aspx?Keyword=RTX2010 http://www.mouser.tw/Search/Refine.aspx?Keyword=RTX2010

kens 12y ago
I looked on Alibaba and Shenzhen suppliers have the HS9-RTX-2010-RH for sale at 10 cents a chip, able to supply up to 100,000 chips per month. How do they do this? They're lying. Various Alibaba vendors list literally every part number they can find as something they are selling. If someone wants it, then they see if they can actually get it. In any case, the real price for the RX2010 was between $1000 and $10,000 according to this thread I found from 1999: http://www.strangegizmo.com/forth/MISC/msg01281.html http://www.strangegizmo.com/forth/MISC/msg01281.html
- mud_dauber 12y ago
  Of course they are. The last place I'd go for reputable semiconductor suppliers is Alibaba. The LAST.
nraynaud 12y ago
it's quite strange that there is not backlash against those manufacturers that don't make their parts or their datasheet available. They are just a pain in the butt and they drive our buying power down.

SixSigma 12y ago

A very closely related processor, the RTX2000, is described in detail in Koopman's book "Stack Computers: the new wave" http://users.ece.cmu.edu/~koopman/stack_computers/index.html http://users.ece.cmu.edu/~koopman/stack_computers/index.html The RTX2010 has had its own wikipedia entry too since 2008 : http://en.wikipedia.org/wiki/RTX2010 http://en.wikipedia.org/wiki/RTX2010

samatman 12y ago

The yearly Forth Day meeting is happening right now, and Chuck Moore (inventor of Forth, designer of the RTX2010) is going to give his annual fireside chat in a matter of hours. I'm honored to be in attendance. So if HN has any questions, this is a good time to ask them. The hangout is here: https://plus.google.com/u/0/115269917987589859757/posts https://plus.google.com/u/0/115269917987589859757/posts

tailrecursion 12y ago
Sam, Chuck designed the Novix but the Harris RTX 2000, which is very similar, was designed by others. These are 16-bit chips (the Novix addressed 128 KB) that use dedicated stack memories, that's 3 ports to memory total. The RTX puts the stacks on chip. The nice thing about these CPUs is they can do stack, alu, and return in parallel, interrupts are cheap, timings are predictable, and programming model is nice if you like Forth. One disadvantage of the design is that clock rate is limited. RAM fetch and instruction processing have to fit between pulses meaning RAM has to be approx twice as fast as clock.