keeping simple

Author: vy

  • Relaxed memory order

    Two interesting posts on the order in which reads and writes happen and are made visible on shared memory multi-processors.  X86 has a strong memory model in which if X=Y=0 and then processor core 1 writes 1 to  X and then Y, if processor core 2 reads X and sees a 1, then its read…

  • Algebra for computer science and function nesting

    The fundamental mathematical basis of computer science is that code and data are the same things. A sequence of bits can represent real numbers, integers, vectors, groups, matrices, video , audio, or programs, algorithms or even proofs. When we try to describe these systems mathematically, then it should not be surprising when we encounter a…

  • Patent 5,995,745

    Adding real-time support to general purpose operating systems AbstractA general purpose computer operating system is run using a real time operating system. A real time operating system is provided for running real time tasks. A general purpose operating system is provided as one of the real time tasks. The general purpose operating system is preempted…

  • RTLinux early paper from 20 years ago

    An early RTLinux paper with Michael Barabanov. real_time_1996 Only 20 years later, the idea is now not too scary.   Real-Time Linux Michael Barabanov Victor Yodaiken March 3, 1996 1 Introduction If you wanted to control a camera or a robot or a scientific instrument from a PC, it would be natural to think of using…

  • ultrafinitism

    I have seen some ultrafinitists go so far as to challenge the existence of 2100 as a natural number, in the sense of there being a series of “points” of that length. There is the obvious “draw the line” objection, asking where in 21, 22, 23, … , 2100 do we stop having “Platonistic reality”?…

  • Windows support in Timekeeper and MiFID II Compliance

    TimeKeeper® PTP/NTP time synchronization software now works on  Microsoft Windows® Operating Systems including Windows 7, Windows 8 and Windows Server 2012. This has been a lot longer in coming than we originally expected because most of our early customers turned out to be Linux only. But bigger customers meant an increasing push for TK support…

  • MiFID2 and security – keeping track of the money

    A shorter version of this post is on the  FSMLabs web site.  MiFID2 is a new set of regulations for the financial services industry in Europe that includes a much more rigorous approach to timestamps.  Timestamps are in many ways the foundation for data integrity in modern processing systems – which are distributed, high speed,…

  • MiFID2 Timestamp regulations

    There are a number of places in the new guidelines that increase the rigor required for timestamping data. One key part covers SI’s (systematic internalizers) who operate kind-of like private exchanges. TimeKeeper’s ability to produce traceable audit and to use multiple sources is designed for precisely this kind of application. Moreover, the inclusion of the…

  • RISC-V and Bloat

    Went to UT today to listen to David Patterson speak about the open RISC  instruction set architecture and processors he and his colleagues are developing.  As a software developer, hearing about free hardware makes me giddy with joy, perhaps with a bit too much of a “let’s see how you like it” edge. It’s interesting…

  • Annals of unintentional irony

    Come back after a trip to see Marc Andreessen’s team of twitter posters complaining wryly about how government is so gosh durn big and citing experts like Milton Friedman. A difficulty of modern economics: I have yet to talk to a non-Keynesian who believes Keynesians intend to cut fiscal spending post-recovery. — Marc Andreessen (@pmarca)…