Stories with Tag noise

• More thoughts on the 1670 modem's weird noises

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  Posted: 2025-03-06 16:18:11

  Verbose tl;dr

  The author investigates strange, rhythmic noises emanating from a US Robotics Courier V.Everything 1670 external modem. Initially suspecting a failing capacitor, they systematically eliminated various hardware components as the source, including the power supply, cable, and phone line. Ultimately, the culprit turned out to be a loose metal plate inside the modem vibrating against the plastic casing at specific frequencies, likely due to the interplay of electrical signals and component vibrations within the device. Tightening the screws securing the plate resolved the issue. The author reflects on the challenge of diagnosing such elusive hardware problems and the satisfaction of finally pinning down the root cause.

  In a blog post titled "More thoughts on the 1670 modem's weird noises," author Rachel Kroll elaborates further on her previous explorations of the unusual auditory characteristics of her U.S. Robotics Sportster 1670 modem. Having previously hypothesized that the curious, almost musical sounds emanating from the device were potentially related to the negotiation process between her modem and a remote server, she delves deeper into this theory by conducting a series of controlled experiments. Utilizing a specific Bulletin Board System (BBS) known for its consistent behavior, she systematically documented the audible variations during the connection handshake. Kroll meticulously describes the distinct phases of the connection procedure, highlighting how the sounds shift and change as the two modems exchange information and settle on optimal communication parameters. She notes that the initial cacophony of seemingly random tones gradually evolves into a more structured sequence, suggesting a progression through different stages of the handshake protocol.

  Furthermore, Kroll draws a compelling comparison between the auditory feedback of the modem and the rich information relayed by the verbose logging feature of her terminal emulator, minicom. She meticulously outlines the parallels between the discrete sounds emitted by the modem and the corresponding log entries displayed by minicom, arguing that the aural output is, in effect, a sonic representation of the complex digital dialogue unfolding between the two modems. This analogy underscores her central thesis: the seemingly strange noises are not random artifacts but rather a direct auditory manifestation of the underlying communication process. She elaborates on the different stages of this process – the initial training sequence, the establishment of error correction protocols, and the final synchronization – and posits that each stage has its own distinct sonic signature.

  Finally, Kroll reflects on the broader implications of her observations, expressing a sense of wonder at the intricate complexity hidden within these seemingly mundane sounds. She emphasizes the value of attentive listening, highlighting how careful observation of even the most commonplace technological phenomena can yield surprising insights into their underlying workings. She concludes with a renewed appreciation for the intricate beauty of this vintage technology, urging readers to embrace the opportunity to explore the hidden depths of the digital world through a closer examination of its sonic landscape.

  • modem
  • 1670 modem
  • noise
  • Troubleshooting
  • Hardware
  • Electronics
  • dial-up
  • Retrocomputing
  • vintage computing
  • Technology

  Summary of Comments ( 23 )
  https://news.ycombinator.com/item?id=43281893

  Verbose tl;dr

  HN commenters discuss the nostalgic appeal of the 1670 modem's sounds, with some sharing memories of troubleshooting connection problems based on the audio cues. Several delve into the technical aspects, explaining the meaning of the different handshake sounds, the negotiation process between modems, and the reasons behind the specific frequencies used. The infamous "Concord jet taking off" sound is mentioned, along with explanations for its occurrence. A few lament the loss of this auditory experience in the age of silent, high-speed internet, while others express relief at its demise. There's also discussion of specific modem brands and their characteristic sound profiles, alongside some speculation about the article author's connection issues.

  The Hacker News post "More thoughts on the 1670 modem's weird noises" (linking to an article about the unusual sounds of a U.S. Robotics 1670 modem) sparked a modest discussion thread with a few interesting points.

  One commenter, going by the username dredmorbius, offered a detailed explanation of the sounds the modem makes during its connection sequence. They break down the different phases, from initial handshaking and training, through to the establishment of a stable connection. They highlight how the changing pitches and rhythms reflect the modem's negotiations with the remote system, adjusting its parameters to optimize the connection quality given the line conditions. This comment provides valuable technical insight into the inner workings of the modem's connection process and helps demystify the seemingly random noises.

  Another commenter, glenbot, notes the nostalgia associated with these modem sounds, recalling them as a familiar soundtrack of the early internet era. This resonates with the original article's sentiment and adds a personal touch to the technical discussion.

  A user named pjmlp questions whether the specific model mentioned (Courier) was actually a 1670. They seem to remember it being a different chipset (Rockwell) and using V.32bis instead of V.34, leading to a speed difference. This introduces a potential factual correction to the original article and sparks a small side discussion about different modem models and their capabilities.

  Another comment, from random_guy, briefly mentions how the article brought back memories and also adds some additional context by noting that the Courier modem used different protocols. This adds to the nostalgic element of the thread while also reinforcing the point made by pjmlp about potential inaccuracies in the original article regarding the modem's specifications.

  While the discussion is not extensive, it offers valuable technical insights, nostalgic reflections, and even a potential factual correction to the original article, making it a worthwhile read for those interested in the history and technology of dial-up modems.

• Surface-Stable Fractal Dithering

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  Posted: 2025-01-23 22:50:11

  Verbose tl;dr

  Surface-Stable Fractal Dithering introduces a novel dithering technique that maintains detail and avoids shimmering artifacts when applied to animated or deforming 3D surfaces. It achieves this by generating spatially correlated dither patterns using fractal Brownian motion, ensuring temporal coherence as the surface changes. This method produces visually pleasing results for various applications like reducing banding in low-bit color displays or adding stylized noise to textures, outperforming traditional dithering approaches in dynamic scenarios. The provided code implementation offers a flexible and efficient way to integrate this technique into existing graphics pipelines.

  This GitHub repository, titled "Dither3D," introduces a novel dithering technique called "Surface-Stable Fractal Dithering" designed specifically for enhancing the visual quality of textures applied to 3D models within a real-time rendering context. Traditional dithering methods, while effective at mitigating banding artifacts arising from limited bit-depth color representation, often exhibit temporal instability, meaning the dithering pattern shifts and shimmers as the camera or object moves. This shimmering effect, though sometimes subtle, can be distracting and detract from the immersive experience, particularly in animated scenes or when viewing objects with fine details.

  Surface-Stable Fractal Dithering addresses this issue by generating a dithering pattern that remains fixed relative to the surface of the 3D model. This is achieved through the use of a fractal noise function that is evaluated in tangent space, a coordinate system intrinsically linked to the surface of the model. As the model moves and rotates, the dithering pattern, being tied to this tangent space, moves and rotates with it, maintaining a consistent visual relationship with the surface. This effectively eliminates the temporal instability that plagues traditional dithering techniques, resulting in a smoother, more stable appearance, even when the camera or objects are in motion.

  The implementation provided within the repository utilizes a pre-computed 3D texture representing the fractal noise. This texture is sampled in tangent space during the rendering process, and the resulting value is used to perturb the color or other relevant properties of the rendered pixels. This approach allows for efficient real-time performance, as the computationally intensive fractal noise generation is performed offline. Furthermore, the fractal nature of the noise function ensures a visually pleasing and perceptually uniform dithering pattern. The repository likely includes code examples demonstrating how to integrate this technique into existing rendering pipelines. This method promises improved visual fidelity for applications requiring real-time rendering of textured 3D models, particularly in scenarios where temporal stability is crucial, such as virtual reality or video games.

  • dithering
  • fractal
  • 3d
  • rendering
  • graphics
  • surface
  • stable
  • Algorithm
  • texture
  • noise
  • shader
  • GPU
  • Real-time
  • image processing
  • computer graphics

  Summary of Comments ( 5 )
  https://news.ycombinator.com/item?id=42808889

  Verbose tl;dr

  Hacker News commenters generally praised the visual appeal and technical ingenuity of the dithering technique. Several highlighted the cleverness of leveraging 3D surfaces for dithering, finding it both unexpected and effective. Some expressed curiosity about the performance and potential applications, particularly in real-time scenarios and stylized rendering. A few commenters delved into the technical details, discussing the specifics of fractal noise generation and the implications of different surface types. There was also a brief discussion comparing this method to traditional dithering techniques and its potential advantages in preserving detail and minimizing banding artifacts. One commenter suggested potential improvements like exploring alternative distance functions and optimizing for different color spaces.

  The Hacker News post titled "Surface-Stable Fractal Dithering," linking to the GitHub repository runevision/Dither3D, has generated a moderate amount of discussion with a generally positive tone toward the presented dithering technique.

  Several commenters express fascination with the visual results of the dithering algorithm, describing it with terms like "mesmerizing" and "beautiful." One commenter highlights the apparent stability of the dithering patterns even when the 3D model is rotated, appreciating the lack of "crawlies," a common artifact in some dithering methods.

  A thread emerges discussing the practical applications of this technique. While some suggest potential uses in stylized rendering or achieving a retro aesthetic, others question the performance implications, especially in real-time scenarios. The original author (runevision) joins the conversation to clarify that the current implementation isn't optimized for speed, focusing instead on exploring the visual properties of the algorithm. They also mention that the technique could potentially benefit from GPU acceleration.

  Further discussion delves into the technical aspects of the dithering method. One commenter correctly identifies it as a variation of ordered dithering, and another speculates about the possibility of applying similar principles to temporal dithering for video. The possibility of using blue noise dithering is also raised, with comparisons to the fractal approach presented.

  One commenter expresses curiosity about the "surface-stable" aspect, prompting the author to explain how the algorithm maps 3D coordinates to a fractal space, resulting in the stable dithering patterns even under transformations. This explanation sparks further discussion about the mathematical properties of the fractal used.

  A few commenters share links to related resources, including articles on different dithering techniques and examples of fractal art. This adds further context to the discussion and provides additional avenues for exploration.

  Overall, the comments reflect a strong interest in the novel dithering technique presented. The discussion explores both the aesthetic and technical aspects, ranging from subjective impressions of the visual results to more in-depth analyses of the underlying algorithm. While some questions about performance and practical applications remain, the overall sentiment is positive and encourages further development and exploration of the technique.