There’s something both satisfying and sad about seeing an aging performer who used to pack a full house now playing at a local bar or casino. That’s kind of how we felt looking at [Craig’s] modern-day bubble memory build. We totally get, however, the desire to finish off that project you thought would be cool four decades ago and [Craig] seems to be well on the way to doing just that.
If you don’t recall, bubble memory was going to totally wipe out the hard drive industry back in the late 1970s and early 1980s. A byproduct of research on twistor memory, the technology relied on tiny magnetic domains or bubbles circulating on a thin film. Bits circulated to the edge of the film where they were read using a magnetic pickup. Then a write head put them back at the other edge to continue their journey. It was very much like the old delay line memories, but with tiny magnetic domains instead of pressure waves through mercury.
We don’t know where [Craig] got his Intel 7110 but they are very pricey nowadays thanks to their rarity. In some cases, it’s cheaper to buy some equipment that used bubble memory and steal the devices from the board. You can tell that [Craig] was very careful working his way to testing the full board.
Because these were state-of-the-art in their day, the chips have extra loops and would map out the bad loops. Since the bubble memory is nonvolatile, that should be a one time setup at the factory. However, in case you lost the map, the same information appears on the chip’s label. [Craig’s] first test was to read the map and compare it to the chip’s printed label. They matched, so that’s a great sign the chip is in good working order and the circuit is able to read, at least.
We’ve talked about bubble memory before along with many other defunct forms of storage. There were a few military applications that took advantage of the non-mechanical nature of the device and that’s why the Navy’s NEETS program has a section about them.
[Ben Cox] found some interesting USB devices on eBay. The Epiphan VGA2USB LR accepts VGA video on one end and presents it as a USB webcam-like video signal on the other. Never have to haul a VGA monitor out again? Sounds good to us! The devices are old and abandoned hardware, but they do claim Linux support, so one BUY button mash later and [Ben] was waiting patiently for them in the mail.
But when they did arrive, the devices didn’t enumerate as a USB UVC video device as expected. The vendor has a custom driver, support for which ended in Linux 4.9 — meaning none of [Ben]’s machines would run it. By now [Ben] was curious about how all this worked and began digging, aiming to create a userspace driver for the device. He was successful, and with his usual detail [Ben] explains not only the process he followed to troubleshoot the problem but also how these devices (and his driver) work. Skip to the end of the project page for the summary, but the whole thing is worth a read.
The resulting driver is not optimized, but will do about 7 fps. [Ben] even rigged up a small web server inside the driver to present a simple interface for the video in a pinch. It can even record its output to a video file, which is awfully handy. The code is available on his GitHub repository, so give it a look and maybe head to eBay for a bit of bargain-hunting of your own.
The common belief is that big companies are out to get the little people by making products that break after a short period, or with substantially new features or accessories that make previous models obsolete, requiring the user to purchase a new model. This conspiracy theory isn’t true; there’s a perfectly good explanation for this phenomenon, and it was caused by the consumers, not the manufacturers.
When we buy the hottest, shiniest, smallest, and cheapest new thing we join the wave of consumer demand that is the cause of what often gets labelled as “Planned Obsolescence”. In truth, we’re all to blame for the signals our buying habits send to manufacturers. Dig in and get your flamewar fingers fired up.