DEC microVAX with tape drive

Bake It To ReMake It: Cooking Old Magnetic Tape To Recover Data

Those of us old enough may remember the heyday of the text adventure game genre from the first time around. London-based Magnetic Scrolls was an early pioneering company producing titles for the first Amiga and Atari ST platforms. Fast-forward to 2017 and [Hugh Steers], the original co-founder and core developer for Magnetic Scrolls has formed an initiative to revive and re-release the original games on modern platforms. Since the 1980s-era DEC MicroVAX used originally for development is not particularly rare in retro computing circles, and media containing source code was found in someone’s loft space, reviving the games was not a tall order.

First, he needed to recover a copy of the original source code from the backup tapes. But there was a problem, it turns out that the decaying tapes used a unstable polyurethane-based binder to stick the oxide material (which is what stores the data) to the backing tape, and this binder can absorb water over the years.

Not much happens until you try to read the tape, then you trip over the so-called sticky-shed syndrome. Secondly you may find that a small amount of the oxide layer sheds from the tape, coating the read head, rollers and guides inside the complicated tape mechanism. This quickly results in it gumming up, and jamming, potentially chewing up the tape and destroying it permanently.

This was further exacerbated by the behaviour of the DEC TK50Z tape drive, which needed to shuttle the whole length of the tape as part of its normal operation.

A temporary solution was to bake the tape in an oven to drive out the moisture and reduce the stickiness enough to run it through the drive safely. Then only the oxide-shedding problem remained. The TK50Z drive was swapped for a TZ30 which shuttles the tape less, but also critically with a simple hack, would allow the heads to be cleaned with IPA between read passes. This was enough to keep the gumming up at bay and allow enough data to be read from the tapes to recover several games worth of code, ready for the re-releasing process.

The video after the break shows [Rob Jarratt] working through the process of the data recovery.

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The Hidden Sounds Of The Past

If you stop to think, the number of pre-recorded voices and sounds you might hear on an average day might number in the hundreds. Everything from subway announcements, alerts on your phone, to sound effects at Disneyland is a sound that triggers in response to an event. [Techmoan] came across a device that many of us have interacted with, but likely never seen: a humble Sontranic 9A Announcer.

In their heyday, these sorts of devices formed the backbone of audio feedback. Messages from Father Christmas were recorded and could be reached when calling a number. Sound effects in theme parks that were activated when a ride activated some hidden switch. Anything where the sound effect needed to play on some sort of trigger.

An interesting thing to note is that this is not a reel-to-reel system. The tape is of the standard 1/4″ magnetic variety, perhaps a little thicker for extra durability. It instead sits in the top of the machine; coiling and uncoiling like a two-dimensional lava lamp. Additionally, there’s nothing clever about detecting the beginning or end of the audio loop (as there were four copies of the same recording on this particular tape). In fact, everything about this machine speaks of reliability as the most important design consideration. A reel-to-reel system would just add more points of failure.

After a little bit of diagnosing, [Techmoan] managed to get the device running again and found the message on the tape to be from the phone system, informing the listener that the line is no longer in service. This banal message is perhaps the best testament to the ubiquity of devices like these.

Perhaps in the future, we’ll see an instrument like this magnetic tape-based one created from a similar machine to the one [Techmoan] found.

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Bespoke Storage Technologies: The Alphabet Soup Found In Modern Hard Drives And Beyond

It seems like just yesterday (maybe for some of you it was) we were installing Windows 3.1 off floppy drives onto a 256 MB hard drive, but hard drives have since gotten a lot bigger and a lot more complicated, and there are a lot more options than spinning platters.

The explosion of storage options is the result of addressing a variety of niches of use. The typical torrenter downloads a file, which is written once but read many times. For some people a drive is used as a backup that’s stored elsewhere and left unpowered. For others it is a server frequently reading and writing data like logs or swap files. In all cases it’s physics that sets the limits of what storage media can do; if you choose wisely for your use case you’ll get the bet performance.

The jargon in this realm is daunting: superparamagnetic limit, LMR, PMR, CMR, SMR, HAMR, MAMR, EAMR, XAMR, and QLC to name the most common. Let’s take a look at how we got here, and how the past and present of persistent storage have expanded what the word hard drive actually means and what is found under the hood.

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Recorded Programming — Thanks To Bing Crosby

If you look up Bing Crosby in Wikipedia, the first thing you’ll notice is his real name was Harry. The second thing you’ll read, though, is that he is considered the first “multimedia star.” In 1948, half of the recorded music played on the air was by Bing Crosby. He also was a major motion picture star and a top-selling recording artist. However, while you might remember Bing for his songs like White Christmas, or for his orange juice commercials, or for accusations of poor treatment from his children, you probably don’t associate him with the use of magnetic tape.

In a way, Bing might have been akin to the Steve Jobs of the day. He didn’t power the technology for tape recording. But he did see the value of it, invested in it, and brought it to the market. Turns out Bing was quite the businessman. Want to know why he did all those Minute Maid commercials? He was a large shareholder in the company and was the west coast distributor for their products. He also owned part of the Pittsburgh Pirate baseball team and other businesses.

So how did Bing become instrumental in introducing magnetic tape recording? Because he was tired of doing live shows. You see, in 1936, Crosby became the host of a radio variety show, The Kraft Music Hall. This very popular program was live. That means you have to show up on time. If you go off on a tangent, you’ll run out of time. And if you make a mistake, there is no editing. Oh and one other thing. You have to do a nationwide live show twice: once for the east coast and another for the west. This was cutting into Bing’s “family time” which, as far as we can ascertain was a code phrase for golf.

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Magnetic Tape Storage May Not Be Retro

Magnetic storage is quickly becoming an antiquated technology but IBM may have given it a few more years. Currently, magnetic storage is still manufactured as hard disk drives (HDDs) but you won’t find a tape drive in a modern consumer computer. That’s not likely to change but IBM is pushing the envelope to make a tape drive that will be smaller and more economical than other massive storage options. In many ways, they’re the antithesis of solid state drives (SSDs) because tape drives are slow to retrieve data but capable of holding a lot inexpensively.

Three advances are responsible for this surge in capacity. Firstly, the tape “grains,” where each bit is recorded, have been shrunk by sputtering metal to a film instead of painting it on. Secondly, better servo control allows the reading mechanisms to read those tiny grains with the necessary accuracy. Lastly, stronger computation is used to read the data by using error detection and correction because when your tape is traveling four meters per second, it takes a long time to go back and double-check something.

IBM’s tape drive won’t replace your hard drive but it could back it up daily, many times over.

Check this out if your wetware needs a memory boost or this if your breakfast needs a memory boost.

Interactive Sound With Glove And Tape

Here’s a way to explore new spaces in untraditional manners: a sonophore, or a glove equipped with a tape heads meant to explore spaces with magnetic tape tracing the walls.

This project is a followup to the analogue tape glove from a few years ago. In that project, aligned strips of magnetic tape cover a canvas, leaving anyone wearing the glove to track their hand horizontally swiping across different tracts, or vertically listening to each track.

This project takes a glove similar to the analogue tape glove, but the tape is spread out along the walls of the installation. There’s no way of knowing what strange voices are contained on the tapes; the only way to know is to explore the space.

Video of the project below. It’s a Vimeo, so you know it’s artistic.

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Building A Tape Recorder In 1949

tape

After telling a few stories about how he built a tape recorder as a 16-year-old boy in post-war Germany, [Hans] was finally cajoled into retelling this story in a proper form, giving the Internet one more example of how clever old-school tinkerers could be.

In 1949, [Hans] was but a wee lad of 16 and having built a crystal and tube radio set at 13 and 14 respectively desperately wanted a tour of the local radio station in Hamburg. A kind engineer responded to a letter and a month after requesting a tour [Hans] and his friend found themselves being guided around a proper radio station. One of the most impressive pieces of technology at the time was a tape recorder, which the engineer demonstrated by recording and playing back the voices of [Hans] and his friend. This was the first time [Hans] had ever heard his voice played back and instantly knew he needed to build one of these for himself.

Technical details on the theory and operation of a tape recorder were sparse, but [Hans] managed to come up with an amplifier, tape transport mechanism, a recording and playback head, and homemade magnetic tape made from a reel of iron filings glued to a reel of 8mm film stock.

Testing the equipment, [Hans] and his friend found the device simply wouldn’t work; the homemade magnetic tape was simply too thick, and you couldn’t just go out and buy a reel of magnetic tape. Undeterred, they mailed BASF, the only manufacturer of magnetic tape, and after a month received a 1000m reel of tape.

With tape that worked, [Hans] set about improving his recorder with a tape transport mechanism built from a turntable and a new recording head. This time, his tape recorder worked. When word got around of this amazing machine that could record music, [Hans] was invited to record the local symphony and the speeches for a senior group.

The first commercial reel to reel recorders were released in Germany a little more than a year after [Hans] completed his project, making this one of the more impressive DIY projects we’ve seen.