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Re: [cosmacelf] Membership card latch signal

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  • David W. Schultz
    ... That would be because the OUT4 is a memory read cycle while a DMA IN/LOAD cycle is memory write. Looking at the schematic, the 4013 that generates the
    Message 1 of 31 , Jul 16, 2013
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      On 07/16/2013 03:41 PM, bill rowe wrote:
      > What I find is that the data loads fine when the out4 is triggered by an
      > OUT 4 instruction but not when it's triggered by a dma/load cycle.
      > Looking at the diagram I don't see why the two cases would be
      > different. It's tough to see on a scope because the actual dma cycle is
      > variably delayed from the input switch trigger.
      >

      That would be because the OUT4 is a memory read cycle while a DMA
      IN/LOAD cycle is memory write.

      Looking at the schematic, the 4013 that generates the latch signal is
      reset by /MRD being high.


      --
      David W. Schultz
      http://home.earthlink.net/~david.schultz
      Returned for Regrooving
    • Chris
      I have one of these that has worked out well. http://dangerousprototypes.com/docs/Logic_Sniffer_quick_start_guide
      Message 31 of 31 , Jul 20, 2013
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        I have one of these that has worked out well.

        http://dangerousprototypes.com/docs/Logic_Sniffer_quick_start_guide

        http://www.epictinker.com/Open-Workbench-Logic-Sniffer-p/obc101e1p.htm

        C.W.







        --- In cosmacelf@yahoogroups.com, Andrew Wasson <awasson@...> wrote:
        >
        > Yup, All you have to do is read the first couple of sentences (http://www.saleae.com/counterfeit) to realize who is impacted by the pirated pieces. I'll build my own or save my pennies to buy the real McCoy. I'm glad Josh did the research and posted it before I got around to buying one too.
        >
        > Andrew
        >
        >
        >
        >
        > On 2013-07-19, at 6:29 PM, Lee Hart <leeahart@...> wrote:
        >
        > > Steve Gemeny wrote:
        > > > Josh, I applaud your integrity on this.
        > >
        > > Same here! We all know how much work it is to create something; a
        > > circuit, or program, or any other new and useful thing. And, we know how
        > > much it would bother us if someone stole our work and were selling it at
        > > a ridiculous price. Patents and copyrights are essentially worthless.
        > > That, coupled with the anonymity of the internet makes it easier than
        > > ever to sell pirated goods.
        > >
        > > It's difficult to resist a really cheap price. It takes real character
        > > to decide when a bargain is in fact too good to be true, and turn it
        > > down. But, that's the only way to stop these modern-day pirates.
        > >
        > > --
        > > Never doubt that the work of a small group of thoughtful, committed
        > > citizens can change the world. Indeed, it's the only thing that ever
        > > has! -- Margaret Mead
        > > --
        > > Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
        > >
        >
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