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Re: Max Elf2000 speed?

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  • bobarmstrong_gizmos
    ... Sorry - I only read this group in Digest form any more ... The BCE works fine in the Embedded Elf at 5Mhz, and right now I have an 1805 in there (no LOAD
    Message 1 of 13 , Sep 14, 2005
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      --- In cosmacelf@yahoogroups.com, rileym65 <no_reply@y...> wrote:

      > I sent a BCE chip to Bob awhile back, he
      > wanted to test if the Elf2k could be run at a faster clock. Never
      > heard how his tests worked out tho.

      Sorry - I only read this group in Digest form any more ...

      The BCE works fine in the Embedded Elf at 5Mhz, and right now I
      have an 1805 in there (no LOAD mode in the Embedded Elf) at 3Mhz.
      There's no divide-by-2 in the Embedded Elf clock circuit, either.

      The Embedded Elf is nearly the same circuit as the Elf 2K, but w/o
      the Pixie, the TIL311s, and the switches so anything that works
      there I'd expect to work in the Elf2K too. The Embedded Elf even
      uses exactly the same firmware EPROM as the Elf2K.

      Of course, the Elf 2K has a divide by two in the clock circuit, so
      you'd have to use an oscillator that's 2x the CPU frequency you
      want. And of course the Pixie will only generate usable video with
      a genuine 3.59Mhz colorburst oscillator.

      The ElfDisk card works fine at the higher speeds.

      And as Mike says, the autobaud for the bit banged serial port
      doesn't depend on the clock frequency.

      Bob
    • erd_6502
      ... Embedded Elf? Sounds interesting (and cheaper to build!) Something new on the horizon at Spare Time Gizmos? Got any pictures yet? ... Not surprising, but
      Message 2 of 13 , Sep 14, 2005
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        --- In cosmacelf@yahoogroups.com, "bobarmstrong_gizmos" <bob@j...> wrote:
        > The BCE works fine in the Embedded Elf at 5Mhz...
        > nearly the same circuit as the Elf 2K, but w/o
        > the Pixie, the TIL311s, and the switches so anything that works
        > there I'd expect to work in the Elf2K too.

        Embedded Elf? Sounds interesting (and cheaper to build!) Something
        new on the horizon at Spare Time Gizmos? Got any pictures yet?

        > The ElfDisk card works fine at the higher speeds.

        Not surprising, but good to have confirmed.

        -ethan
      • Robert Armstrong
        I ve uploaded a photo to the Cosmac Elf group - it s right after Ethan s Poptronics Elf :-) The Embedded Elf is the same size as the ElfDisk daughter card
        Message 3 of 13 , Sep 14, 2005
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          I've uploaded a photo to the Cosmac Elf group - it's right after "Ethan's
          Poptronics Elf" :-)

          The Embedded Elf is the same size as the ElfDisk daughter card (and the
          eventually to be released Elf Video card and Elf Sound card). It has the
          same expansion bus as the Elf2K and stacks with the disk/video/sound/etc
          cards to form a cute little "cube". The Embedded Elf is basically the same
          circuit as the Elf2K and can even use the same firmware EPROM as the Elf 2K.


          The primary differences are that the Embedded Elf lacks the switch
          interface, the TIL311 displays (although the EELF does have 8 LEDs for POST
          output), the voltage regulator (the EELF requires an external 5V supply),
          and the Pixie circuit. The EELF does have the same non-volatile memory (you
          can see the coin cell in the photo) and bit banged serial port with DS275
          EIA level shifter as the Elf2K. The push button you see in the photo is
          reset.

          As the name suggests, I did the EELF for a friend who wanted to use an
          1802 as a embedded controller. He designed his own I/O card for it that
          stacks on top of the expansion port, along with the ElfDisk card.

          It seems like there are enough Elf designs floating around as it is so I
          haven't made any real attempt to publicize it, but if enough people are
          interested I could order a few more PC boards.

          Bob


          -----Original Message-----
          From: cosmacelf@yahoogroups.com [mailto:cosmacelf@yahoogroups.com] On Behalf
          Of erd_6502
          Sent: Wednesday, September 14, 2005 7:26 PM
          To: cosmacelf@yahoogroups.com
          Subject: [cosmacelf] Re: Max Elf2000 speed?



          --- In cosmacelf@yahoogroups.com, "bobarmstrong_gizmos" <bob@j...> wrote:
          > The BCE works fine in the Embedded Elf at 5Mhz...
          > nearly the same circuit as the Elf 2K, but w/o
          > the Pixie, the TIL311s, and the switches so anything that works
          > there I'd expect to work in the Elf2K too.

          Embedded Elf? Sounds interesting (and cheaper to build!) Something
          new on the horizon at Spare Time Gizmos? Got any pictures yet?

          > The ElfDisk card works fine at the higher speeds.

          Not surprising, but good to have confirmed.

          -ethan






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        • erd_6502
          ... Heh... nice. ... Well, Bob, you know I can t resist stuff like this. If you do a run, I m in. I even have the DialLight LEDs (one of the more expensive
          Message 4 of 13 , Sep 14, 2005
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            --- In cosmacelf@yahoogroups.com, "Robert Armstrong" <bob@j...> wrote:
            >
            > I've uploaded a photo to the Cosmac Elf group - it's right after
            > "Ethan's Poptronics Elf" :-)

            Heh... nice.

            > It seems like there are enough Elf designs floating around
            > as it is so I haven't made any real attempt to publicize it,
            > but if enough people are interested I could order a few more
            > PC boards.

            Well, Bob, you know I can't resist stuff like this. If you do a run,
            I'm in. I even have the DialLight LEDs (one of the more expensive
            single parts I see in the picture) in my parts bin.

            One request - if you do another run, is there room to have a second
            row of pins in parallel with one edge of the SRAM to permit using
            either a .6" 62256 _or_ a .3" 32K cache SRAM? I have both on hand,
            but some people might find one or the other easier to track down. I
            would expect, though, that one wouldn't want to use the BBU capability
            with a cache SRAM - the standby current would likely be too high and
            the battery would be sucked dry in no time.

            -ethan
          • Andrew Wasson
            Bob that s cool! I ll take a board if/when you get around to it. Nice work! Andrew
            Message 5 of 13 , Sep 14, 2005
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              Bob that's cool!
              I'll take a board if/when you get around to it.
              Nice work!
              Andrew




              --- In cosmacelf@yahoogroups.com, "erd_6502" <erd_6502@y...> wrote:
              > --- In cosmacelf@yahoogroups.com, "Robert Armstrong" <bob@j...> wrote:
              > >
              > > I've uploaded a photo to the Cosmac Elf group - it's right after
              > > "Ethan's Poptronics Elf" :-)
              >
              > Heh... nice.
              >
              > > It seems like there are enough Elf designs floating around
              > > as it is so I haven't made any real attempt to publicize it,
              > > but if enough people are interested I could order a few more
              > > PC boards.
              >
              > Well, Bob, you know I can't resist stuff like this. If you do a run,
              > I'm in. I even have the DialLight LEDs (one of the more expensive
              > single parts I see in the picture) in my parts bin.
              >
              > One request - if you do another run, is there room to have a second
              > row of pins in parallel with one edge of the SRAM to permit using
              > either a .6" 62256 _or_ a .3" 32K cache SRAM? I have both on hand,
              > but some people might find one or the other easier to track down. I
              > would expect, though, that one wouldn't want to use the BBU capability
              > with a cache SRAM - the standby current would likely be too high and
              > the battery would be sucked dry in no time.
              >
              > -ethan
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