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5589Re: How can I send a 4 bit binary code to a 4 to 16 decoder?

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  • Allison Parent
    Aug 4, 2008
      --- In cosmacelf@yahoogroups.com, James Tadlock <jamesa4404@...> wrote:
      >
      > Randy: Thanks for the info. I am running the lovely little ELF2K
      V85. I re-thought my thinking and figure by using an out 4, (some
      number between 0 and 15) I should be able to pull the bits I need for
      input off of D0 to D4 there by having all 16 outputs of the decoder
      usable. Wonder if I need to isolate the decoder from the Elf?. Jim
      >

      Ok it turns out that port 4 and a few other are used on the elf2K
      The basic out statement has only the possibility of 7 ports without
      a banking scheme. TO output a 4 bit value you only need an IOport
      that you can do an OUT n to (read up the instruction in the MPM201
      manual). If you have a ELF2K without any of the added cards out 6 and
      7 are open. If you have the GPIO then all the bits to hook up to are
      there (it's worth getting). I believe basic also could do an out to a
      port.

      Have fun with it.

      Allison



      > --- On Sun, 8/3/08, randy129 <randy129@...> wrote:
      >
      > From: randy129 <randy129@...>
      > Subject: [cosmacelf] Re: How can I send a 4 bit binary code to a 4
      to 16 decoder?
      > To: cosmacelf@yahoogroups.com
      > Date: Sunday, August 3, 2008, 5:43 PM
      >
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      > --- In cosmacelf@yahoogrou ps.com, "jamesa4404" <jamesa4404@ ...> wrote:
      > >
      > > I want to send binary code from a Basic program to a 4 to 16 decoder
      > > like a CD4514 or 74HC4514. I was thinking I could use some code like
      > > out 1,1: out 2,1: and out 3,1: and out 5,1. If that would work how
      > > (which pins) would I pull it off the Elf with? I could also use an
      out,
      > > (0 to F depending on what code I wanted),1 or some other out, but
      > > again, where would I go to read the results from the Elf. I have also
      > > considered using commands like ef1=1: ef2=1 ef3=1 but then I would
      come
      > > up 1 bit short, and again what pins would read off the Elf.
      >
      > The ef1-4 lines are input only.
      >
      > > I'm sure
      > > the Elf can do something like this, but I coming up short on the how
      > > to. Maybe the trick would be to take D0, D1, D2 and D4 into the
      > > decoder.
      >
      > That's right. You might even be able to strobe with an unused
      > n line, but I'm not sure if you would need to only strobe when
      > /mwr was low, (I'd need to look at 1802 datasheet).
      >
      > > Any ideas from the group? I would also like to know for sure
      > > what In(s) and Out(s) and EF's are required by the Elf OS, so I'd
      know
      > > which ones I could play with. Jim
      >
      > You did not say which model of the elf you have. Most probably
      > have used out port 4, but I really don't know about all the variations.
      >
      > Randy
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