Saturday, June 30, 2012

Speak & Math Hack

     Yesterday’s Super Duper Three Dollar Thrift Store Score left my jaw gaping open. For a mere three dollars I managed to walk away with three Texas Instruments Speech devices. A Speak & Spell, a Speak & Read, and a Speak & Math. I brought them all home, shined them up and plugged a 6 Volt adapter into each one. Everyone of them worked, however the Speak & Math was acting a little funny and displayed things in some unknown alien language every once in a while.

     I had read a while back that these things were highly sought after and that people like to modify or “Bend” them to make crazy sounds.  I figured that since I had three of them, one of which worked questionably, it only made sense that I at least try to modify one of them. But, which one?  The Speak & Math was the natural choice since it was the lame brother of the bunch. If I ended up screwing it up, it was of no great loss since it’s operation was less than predictable to begin with.
     I started to rip things apart in my garage. You can see here that I am using the disc portion of the soon to be Hover Sled as a work bench for various pieces of obsolete entertainment. But things started to get a little too hot out there.

                Lately it’s been super hot here in New Jersey. When I say super hot I mean “fry an egg on the sidewalk” type of hot.  It’s not the dry hot that all those folks out west enjoy, it’s a dripping wet, sogafied New Orleans type of hot, that makes a person mean or perhaps “Hot and Bothered” as it was. So I was not going to sit out in this hot box poking and prodding a toy from 1980 to figure out how it worked all so I could end up miserable and sweaty, so I decided to move in doors and do a little research first.

                Luckily, there are tons of sites out there with people’s experiences, thoughts and considerations regarding all manner of Texas Instrument toys from the 70’s and 80’s. A great deal of these were YouTube videos, eBay auctions of modified units, and DIY ‘Bending’ pages. The one thing that I did not see was documentation and pin outs of the IC’s on board any of these units. A little reading revealed that Texas Instruments never released any of the technical information associated with any of their toys. This, it would seem, was going to pose a bigger challenge to my analytical abilities in being able to figure out how things work. I settled on a few pages to get me started. 

                I began with a simple page on “Bending” the unit. This reviewed some of the common features that people are playing with to get looping effects, pitch bending and a variety of “Glitches”. All of these sound pretty cool and indeed expand it’s ability to turn peoples heads but it fell short in providing any real information on how the unit worked, why it worked, and furthermore how you could access it’s data bus.

                I moved on to another page that was associated with an online Calculator Museum that discussed the insides of the Speak & Spell and all of the IC’s inside them. Unfortunately no pin outs but I did find user manuals and a cornucopia of IC information. This page broke things down rather nicely and I was able to get a decent idea of the parts that made up the Speak & Spell.

                Finally I landed on a page with some meat on its bones. It reviewed all the Texas Instruments speaking toys, had old commercials and most importantly an article on how to interface an old Timex Sinclair 1000 computer to the 4 bit bus of the Speak & Spell. JACKPOT!

                The article goes into some pretty interesting detail of how the unit works and what is needed to inject your own data onto the data bus. The two things that it was lacking were, WHERE the bus lines were and WHAT addresses the individual words and phrases were at in the speech ROM. These two need to be experimented with. But this is getting pretty far ahead of things at the moment.

                By this time I cooled off enough to venture back out into the garage to lift the hood on the Speak & Math and snap some pictures. Once that was complete I pulled everything back indoors and did some exploring.

                The first thing I noticed was that the circuitry matched up pretty well with what I had seen earlier on one of the websites with the exception of the IC numbers. Next I noticed the connector that was used to hook up the membrane keyboard to the circuitry.

                I really hate membrane keyboards. Not because they are difficult to use or because they lack that delightful click that a REAL keyboard has. Rather it’s because they are a pain to map out the matrix of what wire connects to what keys. Every time I attempt to do this with my slow multi-meter it usually turns into a big hassle and I end up frustrated.

                More on that later. The picture below is the result of my research and analysis of the board. It appears that this unit has two speech ROMs. At this point I am not really sure why that is. Next to them is the speech synthesizer. Below that is the microcontroller (theBRAIN).  For the purposes of my early analysis, I want to draw attention to the membrane keyboard connector directly beneath the speech synthesize and the lower speech ROM.

                Instead of hopelessly probing the paper thin ribbon cable attached to the membrane keyboard, I decided to peel the keyboard off of the unit and separate the slices of plastic. I then traced the patterns and correlated the pins on the connector to the connections on the ribbon cable.

Below is a table of my efforts for those interested. Remember that these pin numbers are in reference to the photo above.

                Of course, what table of data is any good unless it is verified? So I took the little circuit and powered it up and started playing with a jumper wire. Sure enough when I shorted pins 8 and 13, the unit turned on, and when I shorted pins 9 and 11 the unit started its first program. I think for the purposes of my research and testing, I’ll build a small board where I can short wires together to substitute the keyboard so it does not get in the way of my poking and prodding. Once that is complete I can then start looking around for the data bus, clock signal, and chip selector.

Yet another three dollar purchase has peaked my interests!


       So I understand that it has been forever and a day since I posted this. I just feel that I need to tighten up any loose ends since often I start a million projects and rarely if ever follow-up or finish any of them. This of course is no different but I do feel that the additional research I did warrants at least an addition to this entry.

      With a decent amount of probing around I was able to find the data bus, program data clock, and chip- select pins (I think).

There are some extra wires here since I was doing a lot of experimenting but you get the point. Most of the solder points were to the microprocessor itself since everything logically was attached to it, and I referred to the pin numbers in the article mentioned earlier.

Now that the wires were attached I could work on an interface. The problem however was that this toy used some strange voltages that were alien to me. It used a type of logic called PMOS that operated at -21 Volts. Weird right? So I needed some solution to either work with this or convert it to TTL voltages. I opted for the later because TTL is what I know.
I found that if I routed the signal through a diode to cut off the negative portion of the signal and ran it through a NAND gate with the inputs tied together I would get a nice positive voltage as can be seen below.
The top channel is the Program Data Clock, the one below it is the Chip Select, followed by the four data bits.
Here is the finished setup. Below is a video detailing what I have found.

Tuesday, June 26, 2012

Hover Sled Part III

  YAWN! 6 AM is entirely too early to be sitting in the office at my desk. Yet, here I am torn from the comfy confines of my suburban bed, greasing the wheels of our economy by crunching and pumping out code that makes some things talk to other things in a way that they  both agree on quantities shipped and dollars spent. Such is the life of a codemonkey at a distribution company.

                This past weekend was a long one for me. I took last Thursday and Friday off for a little vacation to celebrate my wife’s birthday. As a result, not a lot was done to the hover sled. I did, however finally fulfill my lifelong dream of knowing what it was like to be flushed down a toilet. There really is no other way to describe the experience I had on this particular water slide at Hershey Park. I use this analogy because of the way you are literally flushed out the bottom of the slide, and more importantly because the people that I encountered at the end of it really did act like turds. They just sort of floated about in the pool with various bits of food stuck to them. Regardless I had a good time and was pretty exhausted when I arrived home. That of course did not stop the wheels of progress. I did manage to get SOME things done to the sled.

One of the things that held my concern was how far the vent pipe would protrude from the bottom of the disc.

If I wanted the vent pipe to be secure against the disc I would need it to protrude at least a little from the bottom. To minimize this distance I used a PVC coupling that I cut down with the miter saw. You can view this below along with mounts for the power plant and the seating.

Once the vent pipe was installed I used a sort of woodworkers putty/glue to secure it into the hole.

With everything all secured and glued into place. I placed the disc up on wood blocks to keep the PVC coupling from touching the ground as it stuck out the bottom of the disc.

The vent pipe sticking out still had me concerned. Sure I could place the skirt over it and for the most part the whole thing would probably work, but I did not like the fact that something would be sticking out of the bottom and could possibly tear the skirt if I hit something. I needed something that would lift the disc off of the ground and still allow some flexibility for the skirt to be freely inflated. Something soft yet ridged. Something I can easily affix to the bottom of the disc. My solution?

These things are cheap and have all the properties to fit my needs. I think I spent $1.99 on one at Target. What else can you buy for $1.99? I just need to run some tests on how I can secure pieces of this to the bottom of the disc. I figure I can slice it down like a meatloafinto 2 inch thick pieces and then line the outer perimeter of the disc with them. I took a small slice and used epoxyto affix it to a scrap piece of OSB. I then placed a weight on top of it and let it sit overnight. The result was perfect. No matter how hard I tried I could not pull the noodle off of the OSB. I just need to slice the noodle down and get to gluing.

So far I have been pretty impressed with my budget on this project. I have only spent, nine dollars on the OSB, sixty-eight cents on the PVC coupling and a dollar ninety-nine on the pool  noodle. I might have to shell out for some more epoxyand that will be around ten dollars but over all for night after night’s worth of entertainment you cannot beat the price.

More to come…

Friday, June 15, 2012

Hoever Sled Part II

So when we last left off I had a nice circle drawn on to a piece of OSB with purple crayon, which if I knew was the same name as some hippie learning center I would have most assuredly choose a red crayon instead. Since then I have been cutting, measuring and of course dreaming.  Not too much of a story to tell here to make this entry interesting, but for those interested I DID eventually find my pipe cutter, while fumbling about in the garage working on the sled. Below you can see my semi-nicely cut disc which will be used to propel me ever skyward. I took the liberty of sanding the edges to make them somewhat smooth as not to tear any experimental skirt that I will be wrapping around it.

Since I already had the saber saw out and warmed up, I went ahead and notched out the vent hole, where the air will enter the skirt. According to Beaty’s Ultra-Simple Hovercraftdesign, the vent hole is placed halfway between the center and the edge of the disc. I obliged him on this. While I was cutting this hole I started to think about the center hole. Beaty uses a bolt to hold the center of the skirtup close to the disc to create a doughnut shape. I wondered if, instead of using a bolt and nut, I instead used a small pipe and then screw a pressure gauge onto the pipe. This way I could get a pressure reading of the air under the skirt. Hmmm I will have to ponder this some more.

At this point I got sick of using the saber saw and decided to pull the miter saw out. My, or should I say my father’s, miter saw scares me. Long ago my father bought me a miter saw from Harbor Freight as a gift. I used it for years and years and years. Then one day the safety guard broke off of it and having an astute fear of having my hand get butchered and bloodied it sat in my garage for another year. 
This fear is not exactly well based but it has provided me with ample aversion to having any such wound inflicted upon my person. Aside from the terrible noise that a spinning blade breaking the sound barrier makes, there was a story that my father once told me that firmly cemented my fear of power tools. 
As all good fathers’ do, they regale tales of yesteryear with a dash of insight and knowledge to include a valuable life lesson in their words of wisdom. The story goes, when my father was a teenager, sometime in the mid-fifties, his father was in the basement showing him the dos and don’ts of running a table saw. Table saws of the period were little more than, gigantic electric motors directly coupled to a spinning blade much like the kind one would imagine in a saw mill located in Walnut Grove. They were big, they were cumbersome, and they were ANYTHING but safe. So the with the flick of the switch, the smell of ozone in the air, and a roaring howl of the spinning blade, my grandfather proceeded to tell my father the safety points of using the saw. 
1.       Hold onto you work, the blade WILL try to snatch it out of your hands.
2.       Wear safety glasses, shit WILL be thrown into the air.
3.       NEVER under ANY circumstances do you put your fingers near the blade like THIS!

The smile quickly, left my grandfather’s face, and he began to turn white. This was probably from him losing most of his blood out of his now bleeding finger. That’s right, probably one of the only safety lectures on the books that resulted in producing an injury rather than preventing one. There was blood everywhere. He eventually went to the hospital and got patched up. My father, as a result, ALWAYS respected power tools from that moment on, I guess such a graphic safety lecture stuck with him. I, on the other hand, was trying to make sense of this story through my father’s tears of laughter the entire time he was telling this to me. I won’t lie, it scared me a little, and in the end I respect power tools immensely. This all came back to me one day when I was in my garage, and I decided to just give the miter saw away to someone. This person ended up being the trash man.
Now, as I have explained before, my house is in a constant state of disrepair and the need arose once again for the use of a miter saw. This cropped up one day in a discussion while I was visiting my father. He quickly, assured me that I did not need to go buy a miter saw he had one that I could borrow. I asked him when he had purchased this one and he told me that he bought two when he purchased the one he gave me. I did not argue or question anything at that point I just merely accepted. HOWEVER, there was a strange element about all of this. When he brought out the saw to me it appeared to have its safety guard removed as well. Apparently my father had the same issues I had with mine. So despite all of my fears, in the end I have to use a miter saw with no safety guard. I suppose that is my lot in life.
Moving on, I used the miter saw to cut out the standoffs for the leaf blower power plant. I had toyed with the idea of boxing it up, but I wanted to make sure that all the air that it required would be delivered to it, so two standoffs would do the trick and keep the weight down. I think I will add a small third one under the junction between the blower and the 90 degree elbow.

Finally, I messed about with some small pieces of wood to get some ideas on a seat.

Things are moving along at a decent pace. Onward and most definitely UPWARD!

Tuesday, June 12, 2012

My Take On Echolink

   For about twelve years now I have been an amateur radio operator. This hobby has rewarded me with endless hours of tinkering, a venue to learn harder theory subjects such as math, and physics, and most noticeably about me, a garage full of junk. The great thing about this hobby is that when I get bored with something I can just put it down and forget about it, at times for years. And when I get interested in the hobby again I can just pick up where I left off or head in a totally new direction. To get a hint of some of the things I have done in the past regarding this hobby you can read about such things here.

So my encounter with Echolink came about in a strange way, as things often do.For those who have no idea what Echolink is, just imagine a type of voIP that not only connects computers together but also radios to make that last jump over long distances via another medium.

So two nights ago I was reading "Ghost in the Wires", by that hacker Kevin Mitnick in it he mentioned a desert town called Pahrump NV, and said that the town was only notable for two things. Art Bell lived there and that legalized whore house the Chicken Ranch also was located there. By the way an excellent read if you have the time, I highly recommend this book.

Now I remember Art Bell from hearing Coast to Coast AM on my little AM radio from time to time growing up. I got a little curious the next day and decided to look him up online. It would appear that he is a radio amateur with the call sign W6OBB.  A little more digging around and I had stumbled upon a forum where he introduced himself. It read

"Hi all,

My name is Art Bell W6OBB. I have just joined the Echolink Universe. I
am Retired from the Broadcast business and would love it if you would
join us at W6OBB-L here in Pahrump, Nevada."

Hmm "Echolink Universe", I wonder what all that is about? Oh yeah and from that post it looks like Kevin Mitnick's statement was correct as well.

In my time of surfing the airwaves I have heard the term "Echolink" pop up a few times. I knew that it was internet connectivity via radio but never thought much of it. Up until that point I had always concerned myself with sending and receiving data over the air exclusively. I suppose now it was time to find out what this is.

I looked up "Echolink" and got the link that I am shamelessly plugging here which was the Wiki entry for it. This gave me a good run down on what the software did and how it worked. From this I found the software's website and more importantly I realized that there was an iPhone app for this. Without reading any further I immediately went to the app store and downloaded this. The app is free of charge. I then continued reading up on this.

It turns out that you HAVE to be a licensed radio operator to be properly registered for the software. No problem there I've had my license for twelve years. To insure that you are licensed you had to sign up for an account and then prove that your are licensed. It just so happened that I had my wallet sized license with me so I scanned that and sent the picture to myself via email. I cropped the scanned license and blew it up for ease of review and sent this off to the software company. They instructed me to wait twenty-four hours.

Damn! I wanted to play with this today!

While I waited I needed to first install the software on a machine at home. This might have posed a problem, since I was at work some thirty miles away from any computer at my house. Luckily I was able to exploit a little known connection in our building to get around security and was able to remote desktop to a machine sitting in my garage. I installed the software and then waited to be verified. Within about four hours I was verified and ready to go.

I had some network problems with running the software from home, so be sure to read up on the documentation, apparently you have to forward ports 5198 and 5199 for UDP, if your machine is sitting behind a router. Once you set up Echolink on a PC and configure your account you can then log in using the iPhone App.

Within no time I was popping in and out of QSOs on repeaters all over the world. I even spoke on one in India and one in Ireland.

This was all fine and good, but I wanted to see how *I* sounded coming over a repeater parsing my audio via Echolink. To do this I used the repeater map to find a repeater close enough to my location to listen to over the radio. I then pointed my directional antenna at this location and tuned into it. I keyed up the repeater using my radio to ensure that I could copy it. Then I logged into Echolink sing the iPhone App and connected to that repeater. I then transmitter to it over my phone, across the internet and then out of the repeater and was able to copy my audio on my radio. It sounded pretty good.

Yup, I like Echolink alright. I'll be playing with this a lot more in the future.

Wednesday, June 6, 2012

Hover Sled Part I

     Ok so some time ago, I saw someone, somewhere floating about on a homemade hovercraft, slapped together with little more than a shower curtain, a piece of plywood and an old vacuum cleaner. This of course set me to thinking about how I could join the ranks of such bold aeronauts of the DIY persuasion. So, I naturally started reading up on the subject and scoured webpage after webpage. Finally I found one that spoke to me in both ease of construction, and in simple enough terms that would allow my mind to easily digest the concepts while allowing for my own improvising of design. The author, WilliamJ. Beaty appears to be a research engineer and as far as I can tell his design for the ULTRA-SIMPLEHOVERCREFT was created for a child’s science fair project. I won’t go into detail or rip off any of the pictures from his website out of respect and more importantly because I am lazy when it comes to displaying all my research. 
This project is really just a pass time for me. My home is in great need of repairs and I always seem to be working on it. Between that, and my career, I need a little break from time to time. I figure a small project that exercises both manual dexterity and engineering skill will keep me somewhat sane. The only restrictions I will put on myself are that the cost needs to be kept at a minimum, there is no time limit on completion, and I have to have fun doing it. This means cutting corners to improvise, and a high likelihood that there will be plenty of silliness involved.  Now with that said I believe it’s time to get started.
The bathroom off of my master bedroom is my current embarrassment. When it was in full functioning order, I was ashamed to “do my business” in it, and now that it is all ripped apart and stripped down to its bare bones, I feel like I am going to the bathroom in a half built, shell of a home. It really is rather depressing. Because of other home projects going on, my bathroom was stuck in a state of limbo. I demolished it to get rid of some potential mold problems, and placed a functioning sink and toilet in it. Then before I knew what was going on, my wife had me working on a back room to get it all painted and have the outlets swapped out to something from this century. As a result of this, my bathroom sat, caught between a world of utter ruin, and a functioning lavatory of mere floor boards and wall studs. This past weekend was my first chance to start working on it again. I replaced a piece of drywall in the ceiling and was prepping things to remove some of the shower plumbing. I needed a pipe cutter to start removing the plumbing from the shower, and the one that I have was hopelessly buried in my garage somewhere. To save time a trip to Lowes was in order.

While at Lowes I spotted some 7/16th roofing OSB that was on sale for nine dollars. I just couldn’t resist and ended up buying a piece. For deep within the recesses of my mind the dreams of sliding about on a personal hovercraft started to bubble forth into my consciousness. A small voice whispered to me, “It is time”, and before I knew what was going on, I was strapping a 4x8 piece of OSB to the top of my vehicle. I never did end up buying a pipe cutter.

Ok, so this is what I have so far. I am roughly following the plans for the ULTRA-SIMPLE HOVERCREFT. For manageability I cut the 4x8 piece of OSB in half so I would not be tripping over it in my garage. Here you see the piece up on saw horses. If you look closely you will see my failed attempt at drawing a circular pattern on the board so I could cut it down into a disk shape. On further inspection of this photo, particularly in the background you will notice that it is also trash night, and I still have left over flags from Memorial Day on the floor of my garage.

       Because, and I must stress again that, I am lazy. I was all ready to engage my saber saw into cutting out this crudely drawn pattern on the OSB, when I started to feel a little pang of shame growing inside of me. Sure this is a crappy ghetto version of a hovercraft but I should at least have an ounce of self respect in making it appear as if some symmetry was involved with its construction. It then became clear to me that I needed a better way to draw a circle on to the OSB.

          I started by carefully measuring where the center of the OSB was and then drilled a ½ inch hole there.

Next I drilled two ½ inch holes in a scrap piece of wood. The distance apart being the radius of the circle, this was around 2 feet. I then secured one side of the scrap wood to the center hole of the OSB and dropped a purple crayon into the other hole.

      I have to say that I was pleased with the results. I was left with a big fat purple line that my saber saw could easily follow.

By the time I had figured all this out it was starting to get late so I decided to save the cutting for another day. However, I was a little curious as to how or if the power plant would even fit onto the disk. 

     There are a few considerations that I need to take into account when mounting this. First is that it is electric so I will need a way to secure the extension cord as not to have it pop out in mid operation, secondly I will need to elevate it because the air intake is on the bottom. And finally I will need a way for it to fit compactly onto the disk while allowing the air to be channeled downward towards the skirt all while I am sitting on it.

This is roughly what I envisioned. I can secure the leaf blower up on a few pieces of 2x4 using clamps so it will not move. Then I can have the air channeled downward using an old 2 inch 90 degree PVC elbow, that I will modify to fit the task. I can then construct a small seat above the PVCelbow to plant my fat ass upon.

                Keep in mind that this is just the plan and is subject to many variations along the way. After all it’s supposed to be fun that I am having, so I am just going to cast a lot of stuff into the wind and just kind of experiment and let the project take me where it will.