Developing In Pascal On The Commodore 64 With Abacus Super Pascal 64

February 14, 2024 by Maya Posch 8 Comments

Abacus Super Pascal 64 for the Commodore 64.

Most people associate the Commodore 64 with Commodore BASIC and precompiled applications, but it also had a number of alternative development environments produced for it. One of these was Super Pascal 64 by Abacus. A solid introduction to this software package is provided in a video tutorial by [My Developer Thoughts] on YouTube. This uses the Abacus Super Pascal 64 software and manual from the [Lyon Labs] website, which incidentally has a lot more development environments and operating systems for the C64 listed for your perusal.

Abacus’ Super Pascal supports the official Pascal language, requiring nothing more than a Commodore 64 and two Commodore 1541 floppy disk drives to get started. One FDD is for the Super Pascal software, which boots into the development environment, the other FDD and the disks in it are the target for the current project’s source code and compiled binary. Although the lack of support for FDDs other than the 1541 is somewhat odd, this comes presumably from the operating system nature of the development environment and the 1541 being by far the most common FDD for the C64.

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Shuji Nakamura: The Man Who Gave Us The Blue LED Despite All Odds

February 14, 2024 by Maya Posch 68 Comments

With the invention of the first LED featuring a red color, it seemed only a matter of time before LEDs would appear with other colors. Indeed, soon green and other colors joined the LED revolution, but not blue. Although some dim prototypes existed, none of them were practical enough to be considered for commercialization. The subject of a recent [Veritasium] video, the core of the problem was that finding a material with the right bandgap and other desirable properties remained elusive. It was in this situation that at the tail end of the 1980s a young engineer at Nichia in Japan found himself pursuing a solution to this conundrum.

Although Nichia was struggling at the time due to the competition in the semiconductor market, its president was not afraid to take a gamble on a promise, which is why this young engineer – [Shuji Nakamura] – got permission to try his wits at the problem. This included a year long study trip to Florida to learn the ins and outs of a new technology called metalorganic chemical vapor deposition (MOCVD, also metalorganic vapor-phase epitaxy). Once back in Japan, he got access to a new MOCVD machine at Nichia, which he quickly got around to heavily modifying into the now well-known two-flow reactor version which improves the yield.

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How Different Are SpaceX Thermal Tiles From The Space Shuttle’s?

February 14, 2024 by Maya Posch 9 Comments

When SpaceX first showed off the thermal tiles on its Starship spacecraft that should keep it safe when re-entering the Earth’s atmosphere towards the loving embrace of the chopsticks on the launch tower, some similarity to the thermal tiles on NASA’s now retired Space Shuttle Orbiter was hard to miss.

Electron microscope image of the fibrous part of a Starship thermal tile, showing very large fibers. (Credit: Breaking Taps, YouTube)

Yet how similar are they really? That’s what the [Breaking Taps] channel on YouTube sought to find out, using an eBay-purchased chunk of Shuttle thermal tile along with bits of Starship tiles that washed ashore following the explosive end to the vehicle’s first integrated test last year.

To answer the basic question: the SpaceX engineers responsible for the Starship thermal tiles seem to have done their homework. An analysis of not only the structure of the fibrous material, but also the black IR-blocking coating, shows that the Starship tiles are highly reminiscent of the EATB (introduced in 1996) tiles with TUFI (toughened unipiece fibrous insulation) coatings with added molybdenum disilicide, which were used during the last years of the Shuttle program.

TUFI is less fragile than the older RCG (reaction cured glass) coating, but also heavier, which is why few TUFI tiles were used on the Shuttles due to weight concerns. An oddity with the Starship tiles is that they incorporate many very large fibers, which could be by design, or indicative of something else.

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Apple Pushes Back On Right To Repair Bill Due To Parts Pairing

February 14, 2024 by Maya Posch 66 Comments

After previously supporting one in California, Apple has made an about-face and is now pushing back against a “Right to Repair” bill (Senate Bill 1596) currently under consideration in Oregon. The reason for this appears to be due to this new bill making parts pairing illegal, as reported by [404media] and [PCMag].

The practice of parts pairing is becoming ever more prevalent with Apple devices, which links specific parts of a system such as cameras, displays, batteries, and fingerprint sensors to the mainboard. During the open hearing on the newly proposed Oregonian bill, Apple’s [John Perry] insisted that this parts pairing is done for user security, safety and privacy.

Even in we take that claim at face value, the fact remains that with parts pairing in place, only authorized Apple repair centers can routinely replace components — while user repairs are limited to specific devices with limited part availability. Even in the latter case the user still has to contact Apple to have them reauthorize the replaced part. This is becoming an issue with Apple’s MacBooks as well, where the lid angle sensor requires calibration using a proprietary tool.

During the same hearing, the director of an Oregon nonprofit organization noted that of the 15,000 iPhones which they had donated to them last year, only 300 could be refurbished due to parts pairing. The remainder of otherwise perfectly fine phones are discarded for recycling, which is terrible for everyone but Apple. Whether the parts pairing element of the bill survives it to the final form remains to be seen, but if it passes it’d set the trend for future bills in other states as well as amendments to existing ones.

Thanks to [paulvdh] for the tip.

A Clock Made Out Of Electromechanical Relays

February 13, 2024 by Maya Posch 11 Comments

Electromechanical circuits using relays are mostly a lost art these days, but sometimes you get people like [Aart] who can’t resist to turn a stack of clackity-clack relays into a functional design, like in this case a clock (article in Dutch, Google Translate).

It was made using components that [Aart] had come in possession of over the years, with each salvaged part requiring the usual removal of old solder, before being mounted on prototype boards. The resulting design uses the 1 Hz time signal from a Hörz DCF77 master clock which he set up to drive a clock network in his house, as he describes in a forum post at Circuits Online (also in Dutch).

The digital pulses from this time signal are used by the relay network to create the minutes and hours count, which are read out via a resistor ladder made using 0.1% resistors that drive two analog meters, one for the minutes and the other for the hours.

Sadly, [Aart] did not draw up a schematic yet, and there are a few issues he would like to resolve regarding the meter indicators that will be put in front of the analog dials. These currently have weird transitions between sections on the hour side, and the 59 – 00 transition on the minute dial happens in the middle of the scale. But as [Aart] says, this gives the meter its own character, which is an assessment that is hard to argue with.

Thanks to [Lucas] for the tip.

Piezo Transducers Could Turn Displays Into Speakers

February 13, 2024 by Maya Posch 28 Comments

Will piezoelectric-based speakers replace traditional speakers over the coming years in space-constrained devices? We have definitely seen the use of piezo transducers in e.g. high-end televisions that use the display’s surface not just for the visual content, but also as a highly dynamic speaker. If you extrapolate this principle to something like smartphones, tablets and laptops the advantages are clear: piezoelectric transducers are smaller, more power efficient and do not need any holes in the enclosure. These and other advantages are what [Vineet Ganju] argues in IEEE Spectrum will push the market to adopt this new technology.

When piezoelectric transducers vibrate the display itself to create sound waves, the sound seems to come directly from the image on the screen, a much more realistic effect. (Credit: James Provost) — Piezoelectric transducers vibrate the display itself to create sound waves. (Credit: James Provost)

[Vineet] is the Vice President and General Manager of the audio business unit of Synaptics — which is one of the companies pushing for these piezoelectric transducers to be used for speaker purposes — so there is definitely some bias involved. Even so, it’s undeniable that the speakers in portable devices as well as the average flat panel TV aren’t exactly amazing, with the limited space meaning that audio quality suffers, with lows being generally absent and the resulting audio sounding ‘tinny’. Generally this is where people get external speakers for their TV, and lug portable speakers along with their laptop and other mobile devices.

For TVs, Sony has pushed for its Acoustic Surface Audio technology that uses two or three piezoelectric transducers on their OLED panels, while Samsung sticks to traditional speakers, but places lots of them around the screen with its Object Tracking Sound technology.

Sony’s technology cannot be used with LCD panels, due to the backlight being in the way, so the interesting question here is whether the piezoelectric speaker revolution proposed by [Vineet] will be limited to devices that use OLED or similar backlight-less displays?

Understanding Deep Learning: Free MIT Press EBook For Instructors And Students

February 12, 2024 by Maya Posch 9 Comments

The recently published book Understanding Deep Learning by [Simon J. D. Prince] is notable not only for focusing primarily on the concepts behind Deep Learning — which should make it highly accessible to most — but also in that it can be either purchased as a hardcover from MIT Press or downloaded for free from the Understanding Deep Learning website. If you intend to use it for coursework, a separate instructor answer booklet and other resources can be purchased, but student resources like Python notebooks are also freely available. In the book’s preface, the author invites readers to send feedback whenever they find an issue.

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