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Chapter 1 09-14-04 updated
03-13-05 OK... so here goes a trip down Memory Lane.
I was about 11 or 12 (1960-1961), 5th grade in school and my class went
on a field trip to the Gas Company in Marion, Indiana. On the tour of the
facility we were taken to their "NEW" Computer Room. I realize
now this was actually a Data Processing Machine but possibly would qualify
under the early definitions of a "Computer". The person giving us the tour
pulled out of the waste basket a handful of Paper Tape which we were
told was the output from the computer. I rolled up the Paper Tape and got a couple of more tapes from other students on the trip. I couldn't wait to figure out how this worked. I had kid dreams of somehow using these tapes to build a computer. I saw all of the other machines in the room, the Punch Card equipment, the Card Sorters, the Teletype machines that were used for Data Entry, Card Joggers, Bursters and Decollators, and many more. I didn't have a clue at that time in my life what any of these machines were called or what their job was. But in my pocket was a piece of paper tape that somehow must hold the secret of how computers worked. My first stop on this Journey was a chance question to the wife of an Engineer. I took the piece of tape to a Webelos scout meeting. My Den Mother was a woman named Tony Hanson who referred me to her husband, Eugene Hanson (Gene), an Engineer at the RCA factory in my hometown that made Picture Tubes for TV sets (Remember? "Made in USA"). Gene realized my interest was very intense and put me in touch with another Engineer at RCA named Bill Cable. Bill Cable was a Ham Radio Operator and was able to explain to me about Teletype Machines and Morse Code and he felt I needed a series of Tutorial Lessons in Electronics before I could grasp the understanding of how this Piece of Paper Tape worked in a Computer system. I was out of my league but I went weekly to his home to get private tutoring in Electronics. This was hardcore electronics stuff, Ohms Law, the Right Hand Rule, Frequency Calculations, Resonant Tank Circuits, etc. It was like taking a College course in the 5th grade. I also started about this time going to my Public Library ( Thank You, Andrew Carnegie) and reading books on Electricity, Electronics and Radio. I would see pictures of "Projects" that I would really want very badly to build, but just didn't have enough knowledge to do them by myself.. As I got distracted with other things the Punch Paper Tape from the Gas Company was put away but not forgotten. Digressing for a Moment, To give you a little background, from the age of about 8 I had been playing around with switches, motors, buzzers, and bulbs that could operate off of battery power. (I was forbidden from plugging anything into AC power from the wall.) As a Cub Scout I had built a simple Morse Code light flasher out of strips of a cut up tin can and mounted them on a board. The flashlight bulb would flash on and off as the "Key" was pushed down. I also had torn apart old appliances and machines and had a collection of different kinds of switches, sockets and bulbs, motors, buzzers, and other electrical/electronics parts .I was fascinated by this one special switch that would turn on various bulbs at different rotation points. I would hook up different switches and lamps and make a Do-Nothing circuit that gave different patterns of bulbs for different switch settings. I learned the basics of logic this way (read about it here), though I had no idea at that time in my life what I was doing. It was just learning by trial and error. Fortunately, since my circuits were powered with flashlight batteries I was not able to do any serious damage to myself or the components I was working with. In the Fall of the following year I made a new friend in 6th Grade who was very much like me. I do not remember his last name but he was 'Chuck'. We would exchange notes in class written in Morse Code. Then Chuck discovered this way of writing messages by using a code sheet where A=M and B=Q etc.. My best friend in that class, Pat Hamilton, was a truly gifted brainiac. Pat gave us a code sheet where each letter of the alphabet was represented by a number. If you wanted to secretly code a message you could just add or subtract an amount from it's number and the message was coded. Wow! this was great, I could spend hours writing and decoding messages and not studying my school subjects. I would pay dearly in years to come for that obsessive behavior in the 6th grade. Binary That Winter (6th Grade) all the pieces of the puzzle came together. I started studying Number Systems in school and learned about binary numbers and how 0's and 1's could be used to represent decimal numbers. I realized that the switches and lamps run from a battery were one way of displaying a Decimal Number by a row of bulbs with some on and some off.. I got my first Soldering Gun for Christmas and could connect wires by soldering them instead of twisting and taping them. I set out to build a box to translate binary into decimal numbers. I was way out of my league again, and didn't succeed that time, but did learn some of the basics. Once I understood binary, it was short jump to learning what a binary counter was. I built my first binary counter using switches removed from old floor lamps. (Full Story Here) I got out that piece of Paper Tape from my trip the year before to the Gas Company and tried again to "Decode" it. The time just wasn't ready yet for that to happen. It was, however, at this same time I read an article in Boys Life or Popular Science magazine that explained how to make a computer using a deck of 3X5 cards with holes punched in them using a paper punch and scissors. You coded the binary with the hole punch and using a pair of scissors, cut a small notch between the hole and the outside edge of the card. You could sort the deck of cards with a wire placed through the holes and lifting up. You could get the complement of a number, multiply a number by 2, and there was even some way you could add two numbers. So you can see how my mind was working, holes in cards are the same as holes in paper tape.... therefore you can use paper tapes to do math i.e. "A Computer". A Deck of 3X5 Cards (Story Missing.... Sorry, not done with it yet) Finally, Numbers and Letters -> From Holes! Pat Hamilton and I went together to the Public Library downtown (Marion, Ind.) and he helped me look up a book that was a military training manual for some kind of Teletype Machine. Circa WW2, as I recall. And there it was! in the back of this book was the great mystery of all "Computers" (I thought at that time.) a diagram to convert all those holes punched in the paper tape to a numerical digit. Take that 'Number' and go to a table and look up the character! That Was It! I could decode those pieces of tape into a string of characters. It was fascinating to see names and account numbers, address's and other words appear out of the series of holes punched in that tape from the Gas Company. Now I had to build the machine ('Computer') that would decode those tapes automatically. Finally, I felt like I was on my way to building a real computer. I used bits of scrap lumber, nails, springs, and a small battery powered motor from an old Erector Set to build a simple reader that had one light for each row of holes in the tape. As a column of holes passed under the spring wires, a bulb would turn on if there was a hole in the tape at that row position. Reliability and repeatability was terrible. But it was fascinating to watch the 7 lights flash on and off in a bizarre pattern just like the computers I saw on TV and in pictures from books. The little springs I had used just would not accurately track the columns/rows of holes. I never took this tape reader any further. I was building my first robot at this same time and used the little tape reader mechanism to flash lights on/off on the robot's front panel, for a light show. The mechanism was junked when I moved, and the robot was scrapped for parts for other projects. I had by this time figured out there was no easy way to convert that binary from the tape into numbers and letters using lamps and switches. I would have to wait another ten years to figure out how Hexadecimal really worked. I did get far enough to calculate how many switches it was going to take to build my Paper Tape reader/converter that was to be the brain of my computer. It was at this point in my life that I started doodling ideas on sheets of notebook paper that would later in life become the jumbled piles of paper I now live with. I figured out there was just no way I could afford all the switches and lamps and batteries to build such a contraption. It was actually a good thing though, as I now know this idea would never have worked. In order to do the full conversion I would have needed Logic Devices, either tubes or transistors. It was at this point in my life I met a man named Thomas Planck (Tom), a work at home Radio, TV, & CB Radio repairman. No one else in the world had as much knowledge as Tom did. (I was very certain of that at the time.) He gave me stacks of manuals and old magazines to read through. He patiently explained vacuum tubes, capacitor's, resistance, coils, and the most important thing of all --- If I picked up scrap metal from peoples trash, I could sell it and use the money to buy more electronic components. I was a quick study under Tom because he had the patience to explain things in terminology I could understand. Tom is gone now, and I never had the chance to properly thank him for the thousands of hours he spent with me in his home work shop. My interest went in the direction of Radio and RF equipment for the next year. Tom helped me build an analog "Pot Computer" from plans in Popular Electronics Magazine. It really did add and subtract with fair accuracy. Tom was instrumental in helping me study for all my FCC Licenses and would answer questions about subjects I had trouble understanding from another RCA engineer (Bill Cable) who helped me prepare for those tests. Tom didn't have any formal training or degrees in electronics and was self taught. He had a way with words that I could understand and was always available to explain any subject I had a question on.
Chapter 2 (Please Read Footnote*) The 4 Bit Binary to Hex Converter Box As I started Junior High School I again tried to figure out how to convert binary codes from the punched paper tapes into numbers and letters without using a printed table (chart) to look them up. All on my own I designed a circuit and bought all the parts to build a 4 bit Binary to Hexadecimal converter display box. I used a cigar box to mount all the parts in and soldered all the wires in place and even added a little DC power supply from a Lionel Train Set to operate it off the 115v AC power line. It had 4 switches on the top and 16 flashlight bulbs labeled 0-F to show the HEX equivalent of the binary number. It allowed me to take a tape recording off of my 40meter ham radio receiver, slow it down and convert the tones I heard into binary #'s which I placed on the switches, then the lamps would tell me the Hex equivalent. If I did this as a set of two 4 bit binary characters I could get the two place Hex equivalent for the 8 bit binary number which I would look up on an ASCII character table. I instantly had the desire to build a double box so I could do all 8 bits at one time rather than doing the first 4 bits then the last 4 bits. I later did build the 8 bit converter but spent many a fun hour translating those teletype news wires into readable text from that first 4 bit cigar box converter unit. This was entirely my own design -- no one helped me. In retrospect this was one of the first good designs I ever did entirely on my own. (I guess I was little bit of a 'Hacker' even back then.) It was at this time (7th grade - 1962) I found the Mother Lode of all electronic junk. It was a huge panel 4 feet wide and three feet tall with about 200 pilot lamps mounted in holes. There was wires, switches, larger round holes where meters had once been mounted. It was along the railroad tracks behind a foundry on the path I walked to and from McCullough Junior High School. It was too big for me to carry home, so the next day I took tools to school with me and on the way home I salvaged every part off that panel. I was so disappointed when I discovered that all those lamps didn't have a filament! I looked up the bulb # in a catalogue and discovered they were neon lamps. At the time I didn't know how they worked. I wanted to build that double 4 bit binary converter ( 2 X 4 = 8 Bits) since I had the 32 pilot lamps I needed for the display. I designed a nicer smaller box with a metal lid and had planned to make this one portable by using batteries. But if I was going to use the neon pilot lamps I would have to buy very expensive "B+" batteries. It would take two of them to get the 90 volts to operate the neon lights. My first test of lighting the bulbs was a disaster. I burnt up wires and destroyed the very expensive batteries trying to get those danged neon lights to illuminate. I by chance found an article in an old Popular Electronics magazine that explained I had to use a series current limiting resistor. It even gave a suggested value and with a little experimenting around, after buying a second set of batteries, I figured out the proper value. So now the lamps worked and it was now time to buy the switches for the 8 bit (32 lamp) converter box . The 8 bit Wide Binary to Hex Converter Box I was by this time buying my electronic parts from mail order catalogues. I was ready to get the 8 switches to build the double sized 8 bit wide binary converter. I worked out my schematic and parts list but found there was no such thing as an 8 pull double throw switch. I was heart broken. I had a camping trip with the Boy Scouts the next weekend and my Scoutmaster Bill Z. Littlefield, Assistant Scoutmaster Gene Hanson and a parent chaperone on the trip Mr. Hargraves all worked together as Engineers at RCA in Marion. I told them of my dilemma and they said they would try to find me the switch. I went to my regular scout meeting the following Monday night and Bill told me there was no such switch made by any company. They wanted my schematic and parts list to see if there might not be a better way to accomplish the same thing without the unavailable 8 pull double throw switch in my design. I am sure RCA didn't appreciate three of their Engineers working on a project for a Boy Scout. (Maybe they did it on their lunch hour. :-) I was informed by my scout leaders that the best way to do the double (8 bit) box was to just build two of the original circuit I had designed and use the Qty 8 - 4 pull double throw switches from my original design. They also did a 2nd optional design using cheaper 2 pull double throw switches. A week later, a 3rd design with even cheaper single pull double throw switches. Finally I got a schematic from the Engineering Department at RCA on Drafting Paper that used 8 single pull single throw switches ( the simple toggle switch). This 4th design required 8 transistors 25 or 30 capacitors and resistors and a whole lot more work than my original design using just switches and bulbs. I was confused? I took their drawing from the 4th design and tried to figure out how each component worked but just couldn't understand it. This 4th design had to be ruled out because it required a higher voltage (more batteries) to operate and required an additional B- battery of -22 volts plus all those expensive transistors. Whew... OK now what? I had to politely let all of the Scout Leaders / Engineers know I just hadn't had time yet to work on the finished box. (I was stalling because I didn't want to build the more complicated 4th design using transistors.) As it turns out I used the third design of Qty 8 Single pull double throw switches because the notes on the sketch said the selected lights would flash on and off. I thought this would look really cool and I only had to buy 8 of one type switch. Of course since no one had ever tested the design, when I put it all together it didn't work. I took the whole thing to Bill Littlefield who took it to work for the engineers at RCA look at. This precipitated yet another go around of design. It turns out the neon pilot lamps I had used required a higher trigger voltage than the books said. They adjusted the value of a few resistors and the little box quickly and easily converted 8 bit binary numbers into 2 hexadecimal digits via flashing neon lights. It ran it's entire lifetime (9yrs.) on those original batteries. (The second set, not the first set I blew up.) Some weeks later I found out from a fellow Scout, the son of one of the engineers, that his dad thought I was a little strange. They couldn't understand why I didn't just use a printed paper table and look up the values like he did. The group of engineers did however continue to think about the design. They later gave me a 5th design using single pull single throw switches, neon bulbs, and just a couple dozen resistors. It was the simplest of all the designs but I long ago lost the schematic and never built that design to see if it worked. I have recently tried to recreate that schematic from memory but can't exactly recall how it was laid out.. My best recollection is that it used resistors for voltage dividers. However I was able to recreate from memory that 3rd design I actually used back in 1962. That 8 bit converter stayed with me for 9 years and earned me the Electronics Merit Badge in Boy Scouts. It got used a lot in my freshman year of college at Purdue University in my beginning computer classes. It was discarded when I moved from Tennessee to Florida in 1971. Oh Yes, and the Paper Tape from the Gas Company?... well It got lost in one of many moves. When I did finally learn about computers in college the very first programs I did were on Punch Cards. We ran the punch cards through a reader that created a Punch Paper Tape which the university used to run through the computer on campus. We got our results back on form feed green bar paper. When I dropped out of Purdue in 1970 I threw away boxes of Paper Tape Rolls with programs I had written in Fortran for both my college courses and my own amusement. Paper Tape in the "Real World" Paper tape came into my life several more times as I moved from computer to computer. In college at Purdue as I mentioned above. When I worked for a company in Ft. Wayne Indiana called "Tech Services" I used an 8 hole system to program a very early mini-main frame computer I don't remember exactly which model it was but I remember it was manufactured by DEC (Digital Equipment Corporation) I looked at several pictures on the WWW recently and my best guess is it was a model PDP-8. The 8 hole tapes were made for me by an outside company from my assembly code that was typed on a teletype machine through a dedicated phone line. The paper tapes would arrive a day or so later by courier. While living in New Jersey in 1979-1980 I found a monster machine built to print address's on envelopes. It was in the dumpster at the Sun Chemical Office Building where I worked. It was probably 20 years old and operated from a small controller box with a keyboard and would both punch and read 8-hole paper tapes. I junked the address machine but kept the Reader/Punch when I moved to California. In the early 1980's I worked with an 8-hole reader that was part of a Cash Vault System for a bank customer of my employer (Glory USA Inc.). I interfaced the banks computer to Glory's coin counting equipment. I never learned the exact programming language of that system, but I know every time we crashed the system out came the tapes to reload the programs. I remember it seemed to take forever for all the programs to load from that roll of yellow punch tape. In California in 1983 I bought a small NEC 4 bit CNC micro controller built for a machine tool programmer. It was the first Micro Controller device I ever owned. I used the Reader/Punch from the Envelope Printer I had found in New Jersey to both punch and read 8-hole paper tapes for Input and Output to this Computer. The keyboard from the Reader/Punch was the Input for both programs and data. The output of my little 4 bit computer was a paper punch tape printout that printed as alpha-numeric characters. I actually did some useful work with this little home brew computer. I created a matrix driver and math program to read and store data from several test jigs I built for a product design. I even wrote several programs that would calculate a log scale value and output it to a table. It's last task was as a cross-compiler for the 8080 family of micro controller's. The only missing piece of that system was the printer. I never had the time or money to buy a printer unit and write the interface program. The computer, tape drive, and all the modules I built were junked when I moved to Palm Springs in 1988. By that time I had moved on to the IBM PC-XT Clone and paper tape devices were just about gone from the marketplace, and were completely gone from my life.. So now you see why, had it not been for punched paper tape I wouldn't be sitting here right now typing this for publication on the WWW :-) [ BACK ]Footnote* (Chapter 2) It is planned to better diagram and explain all the circuits in this chapter with graphics, someday, when time allows. Like I did for '3-way Lamp' circuits |
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