Tuesday, December 27, 2011

11 NOR Gate Ring Oscillator

More Christmas lights.  My day job is doing the plant shutdown thing through Jan. 2 so I am planning to get 36 gates onto this board and route a 3 bit up counter.  At least something with two clocked D Latches and logic.

Wednesday, December 7, 2011

What The Heck Is That Thing?

Well, get a picture of me standing next to it. . .

How handy is that?  I can post a YouTube video directly to a blog post.  The blurriness of the opening shot appeals to me in some "what the heck is that thing?" fashion.  This is the first video I shot and posted of the NOR gates in action.  In this instance as a simple ring oscillator.
NOR Gates

Tuesday, December 6, 2011

Getting Started On The Large(ish) Array

Started to build the latest iteration which should allow for 51 NOR circuits.  Maybe less, no point in crowding parts and making it hard to solder.

Here I am moving along to make sure I can fit three rows (two down one to go) before I start building across the protoboard.  The 110 VAC thing is a bit worrisome but I am disciplined about when to power up and test.  The complete assembly will be properly cased to prevent any inadvertent contact with dangerous voltages.

I think I should have enough NOR gates to do a 3 bit up counter.  Here is my latest least number of NOR gates edge triggered D Latch:

The lower circuit is the actual D latch and the upper circuit is "pulse shaper" which conditions the clock to be of short duration.  The pulse shaper should only be required for every four latches which should save on NOR gates.  I am thinking a 3 bit up counter would take about 35 NOR gates.  I will draw one up in the next few days as build and test circuits on the protoboard.  Maybe have something running this weekend.  I should do a video of the edge triggered D latch at least by this weekend.

Sunday, December 4, 2011

Cellular Automata Or Something Else?

I put together a "ring" of D Flip Flops with the data input set by XORing nearest neighbors, which seems to me to meet a version of the "Conway's Game of Life" rules:
1. Too many neighbors = off.  In this instance too many neighbors is 2, one on each side
2. No neighbors = off. I this instance no neighbors is no one on either side.
3. Just right = on. One neighbor on either side.

Below is a screen shot of the circuit, including a simple preset and the results of manually clocking through 7 states.  It appears to begin repeating at state 4.

If you are interested in designing a simulating digital logic I highly recommend "Cedar Logic Simulator."
You can get it here for free:

The next step is to do the same thing but with all NOR gates.

Saturday, December 3, 2011

Planning for Publication

1. Read "Incredibly Useful Advice for Physics Students Writing a Senior Thesis."  This is a perfect application for the netbook.  Kinda the whole reason you bought it.
2. Use the blog to collect your thoughts and codify your effort.  Conceive, Believe, Achieve are more than just words.  It has worked before and it will work again.  Particularly for  a goal that lends itself to being split into "doable chunks."
3. Collect references for the bibliography and comment on them.
4. Construct an outline and or table of contents for (Working Title) "Cellular Automata Using Optically Routed NOR Gates."
     a. Purpose - Demonstrate a technology for implementing sequential and combinatorial logic circuits from novel components that are comprehensible to an early engineering education audience.  Including how to construct a simulation program.
     b. Survey of previous work by others
     c. My work to present date
     d. How it works in hardware.
     e. Example circuits leading to and including CA
     f. Utilizing MIT open course resources to suggest a curriculum for a hands on digital logic and elementary computer science class for pre college students.
     g. Conclusions
     h. Acknowledgments
     i.  Bibliography
5. Overcome reticence in taking next steps.  The secret to edge triggering sequential circuits was in your previous research from 1995.  What you did and can do takes precedence over what you read and what people tell you is possible.  (I am generalizing something that happened to me in second person voice, hmmmmm).  Oh, well.
6. Query the SPIE conference representatives?  I think that was how I got started last time.  A mentor or collaborator would be nice.
7. Build the the 51 NOR gate board.
8. Simulate 1D CA in Cedar.
9. Work on simulator in Scheme.

Thursday, December 1, 2011

Piano in Paris

Both a disappointment and an inspiration at the same time.  Ahh, dichotomy where would I be without you splitting me in two or three? (trichotomy?  Sure enough it has a Wikipedia entry. . .).  I met some wonderful musicians at Le Chat Noir and a restaurant  in Montmartre but was not able to secure playing time for myself.

 Musée de Montmartre which I thought would be a veritable fountain of Erik Satie information has almost no mention of him. . .hmmmm.  I have a theory it has to do with his love affair with Suzanne Valadon and her (afterwards the affair) husband's ownership of the the building that now houses Musée de Montmartre but that could just be the jet lag talking. . .

At any rate I think there is a interdisciplinary mail art project in there somewhere.  We'll see.

Return From Paris

Went to Paris on sort of whim and because off season is like 1/3 the normal price. The history of technology has been an inspiration to me since my grade school days and Lavoisier was calling me.  I was able on the trip's long flights and occasional sleepless nights to figure out how to make an edge triggered D flip flop from NOR gates only which is imperative for this project which does not allow capacitive coupling.

Also started accessing the SICP (Structure and Interpretation of Computer Programs) lectures and learning resources here:


If you have ever wondered "how" to program, rather than apply example code snippets and hack. This might be just the ticket.  It certainly has opened my eyes.  The video lectures are engaging and inspiring in that they specifically address using imagination as the starting point to programming.  Of course rigor follows but rigor informed by "wishful thinking."  Good stuff!

The original motivation (and continuing) to study SICP is to design a NOR gate only digital simulation environment to complement the hardware.  SICP addresses how to "build" a digital simulator as part of the course.  I think this is just so handy dandy I can hardly stand it. Particularly since it is presented in such a comprehensible fashion.

I was able to watch several lectures during the flights and work through some of the examples on constructors and selectors.  I have learned about these concepts previously in computer science courses but was so intent on "getting done and getting a grade" that I didn't appreciate their power.  Talking to the senior software engineers at work (I am a hardware dude) we now have a much richer and constructive conversation about "how" software is constructed by determining data structures first and letting the functions almost write themselves.

I should go to Paris more often.

If you have a mind to go see Foucault's Pendulum at the

Musée des arts et métiers it may just rock your world.

Saturday, November 19, 2011

Optically Routed NOR Gates 1

Once a upon a time a little before grunge and and a little after new wave I made a $1 bet with a colleague that:
"a solid state electronic technology was available in the 19th century that could be used to build useful digital logic circuits."

The nexus of the bet and the discussion that preceded it was some beefing on my part about having to buy qualified and tested integrated circuits made from silicon in special factories.  Wouldn't it be great if we could skip the silicon foundry and build, test and qualify our own circuits from more readily available raw materials.  My colleagues reply was "if it was possible somebody would have done it already."  I hate that answer I always have and I always will (at least I hope so).  So, I bet my colleague $1 that there was such a technology.

My colleague (long since former colleague) is doing well doing other stuff and has no remembrance of this wager, oh well. . .It took about five years of researching old books, hiking up some interesting blind alleys and of course building circuits to discover one that worked shown below:

This is reprinted from Edward P. Vogel, "Tic Tac Toe Game Using An Optically Routed Gate Array" Proc. SPIE 2863, 407 (1996); doi:10.1117/12.256247:

Notice the "1996", my work has been on hiatus for too long.  Recently I discovered that a certain type of synchronous logic circuit could be constructed using only NOR gates and my interest and enthusiasm for building "useful circuits" has been renewed.

Saturday, May 7, 2011

Slowly I Turn Step By Step. . .

Learning Piano Piece by Piece
Better yet learning a piano piece phrase by phrase.  This is a work in progress so please do check back.  If you have questions about how to apply this method to music you are working on please use the contact form.

The first thing I am going say about learning piano is "slow down."  I don't just mean the tempo you are playing I mean "slow down" as a world view, at least as far as your piano playing is concerned.  That being said if you are in conservatory you are stuck with the pace your master has chosen for you.  For the rest of us who play for our own enjoyment, friends, family and the occasional gig, slowing down can be an important step towards making music more enjoyable and rewarding.  It is very likely that you are going to live a very long time, so don't rush it.  Play what you love and love what you play.

Listen to the Music
If possible get sheet music that comes with a recording.  Pick music that really speaks to you and give it a good listen.  I am big fan of these:

Amsco Publication Concert Performer Series.  For instance "Trois Gymnopedie" by Erik Satie

Alfred Publishing "Jazz, Rags and Blues" by Martha Meir

Listen and follow along with the sheet music as best you can.  Point to the notes.  Listen to it often (another reason to pick something you really love).  

Finding the Phrases
Take a look at your sheet music,  there should be clusters of quarter notes and eighth notes separated by whole and half notes or rests.  Listen and look, find a phrase.  If you have picked a piece that has lyrics it is of course even easier to find phrases in the melody.  A phrase does not need to be a complete sentence.  "I see by your outfit that you are a cowboy"  can be broken down into two musical phrases:
1. "I see by your outfit"
2. "that you are a cowboy."

Likewise bar "1"  shown below is a very nice phrase all by its lonesome self.  These are screenshots from Noteworthy Composer resized in MS Paint.

Using Music Notation Player Software
Type your phrase into music notation SW.  Watch and listen.
Noteworthy Composer is my favorite because when it plays it highlights the notes being played in red and is in sync with the music.  Other free trial SW I have used tend to lag which makes for a less than rewarding experience.

Visual Art Activities
Print your phrase out "big" on 11"x17" paper and color it with crayons.  You can add finger numbers  (your thumbs are "1" is a good "rule of thumb").  Use MS Paint to add other figures to your phrase that you like.  Color and listen the music.  Now play your phrase a few times.

This picture is an "inventory"  of the left hand chords from "Trois Gymnepodie 1"  In no particular order.   I had been working on memorizing it for a couple of weeks and was able to play it much more confidently after coloring this drawing while eating at a Chinese restaurant.  

Movement Activities
1. Just Go Outside - One of my favorite movement activities isn't really a movement activity per se.  I take a keyboard with me in my car, bike, bus or on foot and play from memory out doors.  I once played the first movement to "Moonlight Sonata" in my car during a lunch break while watching two woodchucks smooching.  That experience is with me always when I play.  

2. The Music is in Your Body - You do not need to spend years training in dance to find a musical connection to your body.  Snapping your fingers on off beats while you walk for instance.  Take an inventory of your notes and draw them into a hop scotch game.  Record your music and dance freely to it.  Walking and humming a right or left hand part phrase by phrase is pretty pleasant also.