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(...) I guess it depends on what you want in your firmware. I have been working on my own object-oriented kernel, and I have written an object-oriented kernel for an embedded I/O controller before, and it is a big job. That is just the OS, not (...) (26 years ago, 3-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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(...) So this is a nice start at least. Regarding things you like, I'm going to ignore 1) and 6) because they are not features of byte code, they are features of Java; you either use the JVM and you get them, or you do not use the JVM and you do not (...) (26 years ago, 3-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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(...) For reference, the JVM specification is available online at this URL: (URL) are several features that promote compactness: 1) it is a stack-based bytecode. Operands are pushed onto the stack, a bytecode is executed, and results are pushed onto (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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Stephen's view: -> We want something higher level than FORTH or C so that it will be usable by *everyone*. We also want something higher level than NQC so it will be *usable* by everyone. In short, for semantic level we'd like something that puts (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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(...) classes (...) Yes but in regard to 1) we do not have to implement a compiler, they arer already there, all we need is the VM. (...) There is a stack and a PC. (...) No way, OS/hardware specific stuff should be in the RCX specific (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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I say let us go ahead and make this JVM for the RCX. I am in, Any other volunteers? As I have previously announced (in the LegOS) group that I was going to do this one person has already agreed to volunteer. As a side note take a look at: (URL) (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | IR towers
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Where can you buy more IR towers? -- Richard Clemens Associate Professor Computer Science Department West Virginia Wesleyan College Buckhannon, West Virginia 26201 clemens@wvwc.edu 304.473.8421 -- Did you check the web site first?: (URL) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: IR towers
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Rich Clemens wrote: <snip> (...) Rich: Dacta has them: Tower & cable #N979713 for US$25. 800.362.4308 - - - Nick - - - -- Did you check the web site first?: (URL) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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Java is a very good language, but *NOT* a very good choice of language for robot control. Java's greatest strength is its portability, but portable programs in hardware like the RCX, are not likely to accomplish much. (Have you ever tried to write a (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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(...) Don't forget writing the bytecode interpreter. With JVM, we just have to port that. Writing a bytecode interpreter that is fast, general purpose, supports multithreading & synchronization etc. is no small task. (...) Java would not be used for (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | RCX and Java
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Aren't robots real time systems? Isn't the RCX meant to be a component in such real time systems? Java (as implemented by current virtual machines) is NOT suitable as a platform for building real time systems. The implementation of garbage (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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(...) ??? I think you are making a new interpreter sound harder than it really is. The standard firmware might not be incredibly fast, but it certainly supports multithreading, and synchronization wouldn't be hard to add. The only challenging thing (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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(...) I doubt anyone is considering using the RCX with any OS/language in a hard real-time system. The original firmware nor any of the replacements make the proper guarantees required for such a system (ie, a deadline-based scheduler), and I have (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: Something else is needed, I think...
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(...) I think the basic issue here is we have different ideas in what we want in this interpreted language. You seem to want something closer to the current bytecode, while I want something closer to Java/C++. Certainly if you lower the requirements (...) (26 years ago, 4-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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Has anyone thought of porting OS9 to the RCX. OS9 is a multi-processing, multi-tasking, pre-empted OS that can be put into ROM. It is also a 8 bit OS. Uses Pascal, Basic, Assembly, & C for writing code. Level 1 OS9 fits perfectly into 32K of memory (...) (26 years ago, 5-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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(...) You are provoking me:-) At Enea we are thinking of porting OSE Basic to the RCX. OSE is a multi- processing, multi-tasking, pre-empted OS that can be put into ROM. OSE Basic is a version suitable for 8 or 16 bit microcontrollers with limited (...) (26 years ago, 5-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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I gather then, you know what OS9 is. I have been using OS9 Level I & II, OS9-68K and OS9-X86 for over 10 years. Sound like OSE is very much like OS9. OS9 was developed by Microware for embedded comtrolers like the H8. JAD (...) (26 years ago, 5-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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(...) FYI I have been involved in two (big) projects using java for controlling industrial production one is used to control high speed sorting systems the other for controlling packing of newspapers comming directly from the rotation press. And yes (...) (26 years ago, 5-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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(...) When making a GSM call setup the latency for the call going into a base station/base station controller and out into the next in the chain is 20ms. If you fail you break the GSM specification. How are you going to guarantee that with Java? (...) (26 years ago, 5-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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(...) I don't think anyone is suggesting that Java is appropriate for a hard-realtime system. Personally, I would expect nothing less than an RTOS with a deadline-based scheduler and a low-level language. However, I think the RCX does not have any (...) (26 years ago, 5-May-99, to lugnet.robotics)
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| | Re: RCX and Java
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(...) rotation (...) No, java was picked because the company did not wan't to use C++ as it had some bad experience with projects taking way too long to complete. It had used Visual basic (yieek) before but it tended to be slow and the code was not (...) (26 years ago, 10-May-99, to lugnet.robotics)
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