Retrotechtacular: Where the Linux/UNIX TTY Came From


From time to time we realize that sayings which make sense to us probably will have no meaning for future generations. Two of the examples that spring to mind are “hang up the phone” or in a vehicle you might “roll down the window”. And so is the case for today’s Retrotechtacular. Linux users surely know about TTY, but if you look up the term you actually get references to “Teletypewriter”. What’s that all about?

[Linus Akesson] wrote a fantastic essay on the subject called The TTY Demystified. We often feature old video as the subject of this column, but we think you’ll agree that [Linus'] article is worth its weight in film (if that can be possible). The TTY system in Linux is a throwback to when computers first because interactive in real-time. They were connected to the typewriter-mutant of the day known as a teletype machine and basically shot off your keystrokes over a wire to the computer the terminal was controlling.

This copper pipeline to the processor is still basically how the terminal emulators function today. They just don’t require any more hardware than a monitor and keyboard. We consider ourselves fairly advanced Linux users, but the noob and expert alike will find nuggets and tidbits which are sure to switch on the lightbulb in your mind.

[Thanks Chuck]

Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.

Retrotechtacular: Bakelite Plastics


[ColdTurkey] sent in a really great video for this week’s Retrotechtacular. It’s a half-hour promo reel about Bakelite Plastic. There is so much to enjoy about this film, but we’ve been overlooking it because the first six minutes or so consist of an uncomfortably fake interview between a “Chemist” and “Reporter”. They are standing so close to each other that it’s violating our personal space. But endure or skip ahead and the rest of the video is gold.

Bakelite is an early plastic, and putting yourself in the time period it’s very easy to see the miracle of these materials. The dentures being molded above are made out of phenol formaldehyde resin (to us that sounds like something you don’t stick in your mouth but what do we know?). The plastic pellets take on the shape of the mold when heated — we don’t know if this where the name comes from or if it’s a variation on the name of the chemist who discovered the material: [Dr. Leo Baekeland]. This was the first synthetic plastic, and came at just the right time as it was heavily adopted for use in the electronics and the automotive industry. Both of which were forging new ground at the time.

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Retrotechtacular: Salvaging a Capsized Ocean Liner


The scale of this salvage operation is nothing short of daunting. The SS Normandie was an ocean liner put into service in 1935 and capable of carrying 1,972 people across the Atlantic Ocean. The ship is still the fastest turbo-electric-propelled passenger vessel ever built, so it’s no surprise that it was seized by the US Navy during World War II for conversion to a troop carrier called the USS Lafayette. But in 1942, during retrofit operations, the vessel caught fire and capsized. The topic of today’s Retrotectacular is the remarkable salvage operation that righted the ship. Unfortunately, it was subsequently scrapped as bringing it into service was going to be too costly. Lucky for us the US Navy documented the salvage operation which makes for a fascinating 35-minutes of footage.

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Retrotechtacular: How a Bicycle Is Made

Does your bicycle master boardwalk and quagmire with aplomb? If it was built by the Raleigh Bicycle Company, it ought to. This week’s Retrotechtacular is a 1945-era look into the start-to-finish production of a standard bicycle. At the time of filming, Raleigh had already been producing bicycles for nearly 60 years.

The film centers on a boy and his father discussing the purchase of a bicycle in the drawing office of the plant where a bicycle begins its life. The penny-farthing gets a brief mention so that the modern “safety model”—wherein the rider sits balanced between two wheels of equal size—can be compared. The pair are speaking with the chief designer about the model and the father inquires as to their manufacturing process.

We are given the complete story from frame to forks and from hubs to handlebars. The frame is forged from high-quality steel whose mettle is tested both with heat and with a strain much greater than it will receive in manufacture or use. It is formed from long pieces that are rolled into tubes, flame sealed at the joint, and cut to length. The frame pieces are connected with brackets, which are formed from a single piece of steel. This process is particularly interesting.

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Retrotechtacular: The Genesis of the Transistor

Few births are easy. Even fewer result in a Nobel Prize, and hardly any at all are the work of three men. This 1965 film from the AT&T archives is a retrospection on the birth of the transistor nine years after its creators, [Walter Brattain], [John Bardeen], and [William Shockley] received a Nobel Prize in Physics for their discovery and implementation of the transistor effect.

The transistor is the result of the study of semiconductors such as germanium. Prior to the research that led directly to the transistor, it was known that the conductivity of semiconductors increases when their temperature is raised. The converse is true for metals such as tungsten. Semiconductor conductivity also increases when they are exposed to light. Another key to their discovery is that when a metal such as copper is in contact with a semiconductor, conductivity is less in one direction than the other. This particular property was exploited in early radio technology as seen in crystal radios, for copper oxide rectifiers used in telephony, and for microwave radar in WWII.

After WWII, AT&T’s Bell Labs put a lot of time and research into the study of semiconductors, as their properties weren’t fully understood. Researchers focused on the simplest semiconductors, silicon and germanium, and did so in two areas: bulk properties and surface properties. During this time, [Shockley] proposed the field effect, supposing that the electrons near the surface of a semiconductor could be controlled under the influence of an external electric field.

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Retrotechtacular: Tube Amplifiers


It’s hard to beat this vintage reel for learning about how vacuum tube amplifiers work. It was put together by the US Army in 1963 (if we’re reading the MCMLXIII in the title slide correctly). If you have a basic understanding of electronics you’ll appreciate at least the first half of the video, but even the most learned of radio enthusiasts will find something of interest as they make their way through the 30-minute presentation.

The instruction begins with a description of how a carbon microphone works, how that is fed to a transformer, and then into the amplifier. The first stage of the tube amp is a voltage amplifier and you’ll get a very thorough demo of the input voltage swing and how that affects the output. We really like it that the reel discusses getting data from the tube manual, but also shows how to measure cut-off and saturation voltage for yourself. From there it’s off to the races with the different tube applications used to make class A, B, and C amplifiers. This quickly moves onto a discussion of the pros and cons of each amplifier type. See for yourself after the jump.

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Retrotechtacular: Wax On, Wax Off: How Records Are Made

In this 1942 tour of the RCA Victor plant in Camden, NJ, we see the complete record making process from the master cut production to the shipping of multiple 78RPM shellac pressings. The film centers around a recording of Strauss’ Blue Danube waltz as performed by the 1940s equivalent of studio musicians, the Victor Salon Orchestra.

The master record starts life as a thin layer of molten wax poured on to a hot circular plate in a dust-free room.  Bubbles and impurities are blow torched out, and the wax is left to cool under a steel dome. This perfect disc is carefully passed to the recording studio through a special slot, where it is laid carefully beneath the cutting stylus.

Unlike today’s multi-track recording sessions, the master was cut from the performance of a complete band or orchestra all playing as they would in concert. The sound engineer was responsible for making fast changes on the fly to ensure sonic  and groove width consistency. 

After cutting, the delicate wax undergoes several phases of electrolysis that form the metal master. It is bombarded first with pure gold and then twice with copper sulfate to build a sturdy disc. The copper ionization process also ensures high fidelity in the final product.

Although mighty, this master won’t last long enough to make all the necessary pressings, so a mother matrix is made. This is a negative image of the master. The mother is formed by electrolytically bathing the master in nickel, and then adding a thin film of some indeterminate substance. Another copper bath, and mother emerges. As soon as possible, the master is separated and whisked away to the storage vault.

Since a positive image is needed for pressing, a stamping matrix is made. Mother gets a nickel bath for durability, and then a copper bath to form the stamping matrix. Many stampers are created so that several records can be pressed at once. These images get a chromium plating to help them last through many pressings.

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