Retrotechtacular: Old Transistors

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Regency TR-1

Transistors have come a long way. Like everything else electronic, they’ve become both better and cheaper. According to a recent IEEE article, a transistor cost about $8 in today’s money back in the 1960’s. Consider the Regency TR-1, the first transistor radio from TI and IDEA. In late 1954, the four-transistor device went on sale for $49.95. That doesn’t sound like much until you realize that in 1954, this was equivalent to about $441 (a new car cost about $1,700 and a copy of life magazine cost 20 cents). Even at that price, they sold about 150,000 radios.

Part of the reason the transistors cost so much was that production costs were high. But another reason is that yields were poor. In some cases, 4 out of 5 of the devices were not usable. The transistors were not that good even when they did work. The first transistors were germanium which has high leakage and worse thermal properties than silicon.

socketEarly transistors were subject to damage from soldering, so it was common to use an alligator clip or a specific heat sink clip to prevent heat from reaching the transistor during construction. Some gear even used sockets which also allowed the quick substitution of devices, just like the tubes they replaced.

When the economics of transistors changed, it made a lot of things practical. For example, a common piece of gear used to be a transistor tester, like the Heathkit IT-121 in the video below. If you pulled an $8 part out of a socket, you’d want to test it before you spent more money on a replacement. Of course, if you had a curve tracer, that was even better because you could measure the device parameters which were probably more subject to change than a modern device.

Of course, germanium to silicon is only one improvement made over the years. The FET is a fundamentally different kind of transistor that has many desirable properties and, of course, integrating hundreds or even thousands of transistors on one integrated circuit revolutionized electronics of all types. Transistors got better. Parameters become less variable and yields increased. Maximum frequency rises and power handling capacity increases. Devices just keep getting better. And cheaper.

A Brief History of Transistors

The path from vacuum tube to the Regency TR-1 was a twisted one. Everyone knew the disadvantages of tubes: fragile, power hungry, and physically large, although smaller and lower-power tubes would start to appear towards the end of their reign. In 1925 a Canadian physicist patented a FET but failed to publicize it. Beyond that, mass production of semiconductor material was unknown at the time. A German inventor patented a similar device in 1934 that didn’t take off, either.

Replica-of-first-transistor
Replica of the First Transistor

Bell labs researchers worked with germanium and actually understood how to make “point contact” transistors and FETs in 1947. However, Bell’s lawyers found the earlier patents and elected to pursue the conventional transistor patent that would lead to the inventors (John Bardeen, Walter Brattain, and William Shockley) winning the Nobel prize in 1956.

Two Germans working for a Westinghouse subsidiary in Paris independently developed a point contact transistor in 1948. It would be 1954 before silicon transistors became practical. The MOSFET didn’t appear until 1959.

Of course, even these major milestones are subject to incremental improvements. The V channel for MOSFETs, for example, opened the door for FETs to be true power devices, able to switch currents required for motors and other high current devices.

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History of the Capacitor – The Pioneering Years

The history of capacitors starts in the pioneering days of electricity. I liken it to the pioneering days of aviation when you made your own planes out of wood and canvas and struggled to leap into the air, not understanding enough about aerodynamics to know how to stay there. Electricity had a similar period. At the time of the discovery of the capacitor our understanding was so primitive that electricity was thought to be a fluid and that it came in two forms, vitreous electricity and resinous electricity. As you’ll see below, it was during the capacitor’s early years that all this changed.

The history starts in 1745. At the time, one way of generating electricity was to use a friction machine. This consisted of a glass globe rotated at a few hundred RPM while you stroked it with the palms of your hands. This generated electricity on the glass which could then be discharged. Today we call the effect taking place the triboelectric effect, which you can see demonstrated here powering an LCD screen.

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Prusa Shows Us the New i3 MK2 3D Printer and Where the Community is Headed

Josef Prusa’s designs have always been trustworthy. He has a talent for scouring the body of work out there in the RepRap community, finding the most valuable innovations, and then blending them together along with some innovations of his own into something greater than the sum of its parts. So, it’s not hard to say, that once a feature shows up in one of his printers, it is the direction that printers are going. With the latest version of the often imitated Prusa i3 design, we can see what’s next.

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Hacker’s Toolbox: The Handheld Screw Driver

The handheld screw driver is a wonderful tool. We’re often tempted to reach for its beefier replacement, the power drill/driver. But the manually operated screw driver has an extremely direct feedback mechanism; the only person to blame when the screw strips or is over-torqued is you. This is a near-perfect tool and when you pull the right screwdriver from the stone you will truly be the ruler of the fastener universe.

A Bit of Screw Driver History:

The kind of fun you can have with really cheap bits.
The kind of fun you can have with really cheap bits.

In order to buy a good set of screw drivers, it is important to understand the pros and cons of the geometry behind it. With a bit of understanding, it’s possible to look at a screw driver and tell if it was built to turn screws or if it was built to sell cheap.

Screw heads were initially all slotted. This isn’t 100 percent historically accurate, but when it comes to understanding why the set at the big box store contains the drivers it does, it helps. (There were a lot of square headed screws back in the day, we still use them, but not as much.)

Believe it or not the "Robertson" screw came out before the phillips. Robertson just hated money and didn't want to license his patents. So it's only now that they're in common use again.
Believe it or not the “Robertson” screw came out before the Phillips. Robertson just hated money and didn’t want to license his patents. So it’s only now that they’re in common use again.

Flat head screws could be made with a slitting saw, hack saw, or file. The flat-head screw, at the time, was the cheapest to make and had pretty good torque transfer capabilities. It also needed hand alignment, a careful operator, and would almost certainly strip out and destroy itself when used with a power tool.

These shortcomings along with the arrival of the industrial age brought along many inventions from necessity, the most popular being the Phillips screw head. There were a lot of simultaneous invention going on, and it’s not clear who the first to invent was, or who stole what from who. However, the Philips screw let people on assembly lines turn a screw by hand or with a power tool and succeed most of the time. It had some huge downsides, for example, it would cam out really easily. This was not an original design intent, but the Phillips company said, “to hell with it!” and marketed it as a feature to prevent over-torquing anyway.

The traditional flathead and the Phillips won over pretty much everyone everywhere. Globally, there were some variations on the concept. For example, the Japanese use JST standard or Posidriv screws instead of Philips. These do not cam out and let the user destroy a screw if they desire. Which might show a cultural difference in thinking. That aside, it means that most of the screws intended for a user to turn with a screw driver are going to be flat-headed or Philips regardless of how awful flat headed screws or Philips screws are.

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One Man’s Awesome Collection Of Projects Done Over A Lifetime

[Robert Glaser] kept all his projects, all of them, from the 1960s to now. What results is a collection so pure we feel an historian should stop by his house, if anything, to investigate the long-term effects of the knack.

He starts with an opaque projector he built in the third grade, which puts it at 1963. Next is an, “idiot box,” which looks suspiciously like “the Internet”, but is actually a few relaxation oscillators lighting up neon bulbs. After that, the condition really sets in, but luckily he’s gone as far as to catalog them all chronologically.

We especially enjoyed the computer projects. It starts with his experiences with punch cards in high school. He would hand-write his code and then give it to the punch card ladies who would punch them out. Once a week, a school-bus would take the class to the county’s computer, and they’d get to run their code. In university he got to experience the onset of UNIX, C, and even used an analog computer for actual work.

There’s so much to read, and it’s all good. There’s a section on Ham radio, and a very interesting section on the start-up and eventual demise of a telecom business. Thanks to reader, [Itay Ramot], for the tip!

A Comparison of Early Graphics Cards

We have to admit, we expected to be bored through [The 8-Bit Guy]’s presentation, only to stay riveted through his comparison of early graphic card technology.

Some presentations get a bit technical, which isn’t bad, but what is so interesting about this one is the clear explanation of what the market was like, and what it was like for the user during this time. For example, one bit we found really interesting was the mention of later games not supporting some of the neat color hacks for CGA because they couldn’t emulate it fully on the VGA cards they were developing on. Likewise, It was interesting to see why a standard like RGBI even existed in the first place with his comparison of text in composite, and much clearer text in RGBI.

We learned a lot, and some mysteries about the bizarre color choices in old games make a lot more sense now. Video after the break.

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Wiring was Arduino before Arduino

Hernando Barragán is the grandfather of Arduino of whom you’ve never heard. And after years now of being basically silent on the issue of attribution, he’s decided to get some of his grudges off his chest and clear the air around Wiring and Arduino. It’s a long read, and at times a little bitter, but if you’ve been following the development of the Arduino vs Arduino debacle, it’s an important piece in the puzzle.

Wiring, in case you don’t know, is where digitalWrite() and company come from. Maybe even more importantly, Wiring basically incubated the idea of building a microcontroller-based hardware controller platform that was simple enough to program that it could be used by artists. Indeed, it was intended to be the physical counterpart to Processing, a visual programming language for art. We’ve always wondered about the relationship between Wiring and Arduino, and it’s good to hear the Wiring side of the story. (We actually interviewed Barragán earlier this year, and he asked that we hold off until he published his side of things on the web.)

The short version is that Arduino was basically a fork of the Wiring software, re-branded and running on a physical platform that borrowed a lot from the Wiring boards. Whether or not this is legal or even moral is not an issue — Wiring was developed fully open-source, both software and hardware, so it was Massimo Banzi’s to copy as much as anyone else’s. But given that Arduino started off as essentially a re-branded Wiring (with code ported to a trivially different microcontroller), you’d be forgiven for thinking that somewhat more acknowledgement than “derives from Wiring” was appropriate.

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See what we mean?

The story of Arduino, from Barragán’s perspective, is actually a classic tragedy: student comes up with a really big idea, and one of his professors takes credit for it and runs with it.

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