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6617Re: Membership Card - Ultra Low Power Variant

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  • awasson2001
    Mar 13, 2010
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      Steve, I have a box of vintage Numitron tubes that I was thinking would make a great SteamPunk ELF display. Not as nice a display as the Nixi's but much lower consumption I would expect.

      If I make anything happen with them, I'll post a picture to the board.


      --- In cosmacelf@yahoogroups.com, "aa3nm" <steve@...> wrote:
      > Lee,
      > Thanks for the inputs, in time I think they'll be put to good use. I really like your Steam Punk idea. It's got me thinking about using Nixie Tubes for an Octal Display. Clearly not low power, nor "Spit & Coin" battery compatable, but it would be fun… Octal display would need a way to generate assembly listings in Octal to be easily read, but that could be managed a number of ways. Could be a fun project at some time in the future.
      > I appreciate all your hard work with all the Membership card version you designed and posted. I had hoped to add value to those efforts by moving this one along as you and Herb are doing with the other version.
      > In the interim, some things have come up that necessitate me setting this project aside for a while. No issues other than available time. I thought I had a small window and now other wicks have been turned up and that window has closed again. If I find another opportunity I may see if I can nudge it along a bit, hopefully with your support.
      > I'm sure you recognize the scenario – it's all about hitting "critical mass" – getting enough momentum built up to move a project far enough along that finishing it is easier than boxing it up for later. This time, my goal of a basic ELF that could be operated, display and all from a "spit and coin" battery will have to hold on a while longer.
      > If anyone else chooses to "nudge the bowling ball along a bit" feel free to ping me since one never knows how the available time can shift around.
      > Best to all…
      > Steve Gemeny
      > AKA aa3nm
      > --- In cosmacelf@yahoogroups.com, Lee Hart <leeahart@> wrote:
      > >
      > > aa3nm wrote:
      > > > My goal is to have a truly minimum power ELF that is as simple as
      > > > possible with binary input and output. That being said, the tedium
      > > > of programming anything more than ~50 bytes gets old very fast, even
      > > > with toggle switches (been there too).
      > >
      > > Yep; me too! But, it's a heck of a lot less painful with good switches.
      > > Use the best, easiest-to-use switches you can find. Notice that many of
      > > the traditional minicomputer front panels and organs use piano key like
      > > paddle switches.
      > >
      > > Same for a display. 8 raw binary LEDs are simple and cheap, but have few
      > > other attributes. The LCD display is lower power, and can produce a much
      > > nicer display.
      > >
      > > The small step up to a hex keypad and hex display is a big improvement
      > > over binary.
      > >
      > > You might also consider adding a circuit so a PC's parallel port can
      > > manipulate the front panel switches, as a way to automate the
      > > downloading process.
      > >
      > > Other thoughts: I don't think nearly enough creativity has been applied
      > > to the data entry and display issue. People quickly fixate on the
      > > antique QWERTY keyboard and video text displays. They work , but it
      > > takes a *lot* of hardware and software to support them.
      > >
      > > How about some of these alternative, just for fun... :-)
      > >
      > > - Morse code. A single switch contact is all you need for input.
      > > One bit to drive a speaker is all you need for output.
      > > The software to read and write Morse code is trivial (ham radio
      > > operators have written it many times, so examples are plentiful).
      > > Morse code (especially for numbers) isn't very hard to learn.
      > >
      > > - Voice. Pick 16 audio tones to represent each hex digit 0-F. Whistle
      > > or hum them to input data. A microphone and simple hardware/software
      > > interprets the tones. Play the same tones back to read the data.
      > > Has the advantage that it can also be saved and loaded with a tape
      > > recorder or PC sound card. You "sing" to your computer, and it "sings"
      > > back to you, like R2D2.
      > >
      > > - Calculator. A calculator has special keys for each function; + - /
      > > sin, square, etc. So, have keys labelled PHI GLO BR etc. and an
      > > alphanumeric display that shows assembler mnemonics.
      > >
      > > - Graphics and light pen. The display is a printed drawing of the 1802
      > > architecture, with a single LED at each register, and perhaps 24 LEDs
      > > showing the current memory address and its contents. A light pen
      > > (just a phototransistor in an old pen body) connects to an EFx line.
      > > Poke LEDs to turn them on/off, or move data to/from registers I/O
      > > and memory. The LEDs are multiplexed, so the time at which the light
      > > pen sees the pulse of light tells it which LED you pointed at.
      > >
      > > - Mouse with a view. House the ELF in an old computer mouse case.
      > > Attach a little plexiglass window that has an LED/LCD display.
      > > Set the mouse on a printed drawing of the computer architecture.
      > > As you move the mouse over a box on the drawing, the display on the
      > > mouse shows you the contents of that box. Aim at Register A, and it
      > > displays the contents of RA. Needs a mouse that doesn't "slip", or
      > > is reading codes printed on the page to know where it is. Use the
      > > mouse buttons to increment, decrement, scroll wheel for faster
      > > up/down changes, or to drag data from one register to another.
      > >
      > > - Analog meters and pots (a steampunk Elf). A pair of analog meters
      > > are marked 0 to 15v. A simple D/A converter converts the two hex
      > > digits you get from a typical Elf into two voltages ("A4" displays
      > > as 10v on the left meter, 4v on the right meter). Two pots or
      > > rotary switches under the meters are similarly labelled 0-15v.
      > > Use knife switches for the load/run switches.
      > > etc.
      > >
      > > > BTW, I know you did a lot of work on the power consumption of the
      > > > membership card - Do you have any sense on the consumption of this
      > > > layout? I read on Herb's page that you were "running air" on the
      > > > membershiip card overnight from the charge in the .047 uF cap, but
      > > > adding the LCD display bumps up the power consumption (a lot less
      > > > than LEDs but its still there).
      > >
      > > LCDs vary a lot. The older simpler ones (no backlight, no color, not
      > > multiplexed) are very low. The Lumex display on the LCD Elf I posted
      > > will probably run on less than 10 ua.
      > >
      > > Pullup resistors and memory chips are likely to be your the biggest
      > > problems. You need a design that avoids pullup resistors. The old 5101
      > > chips I used are true CMOS; zero power consumption when all inputs are
      > > static. but almost all modern RAMs (even those claimed to be CMOS) draw
      > > a significant supply current when chip selected even if all inputs are
      > > static.
      > > --
      > > Lee A. Hart | Ring the bells that still can ring
      > > 814 8th Ave N | Forget the perfect offering
      > > Sartell MN 56377 | There is a crack in everything
      > > leeahart earthlink.net | That's how the light gets in -- Leonard Cohen
      > >
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