physics

Hi-MD

Hi-MD is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Hi-MD rather than just read about it. In short: Hi-MD is a magneto-optical disc-based data storage format. It was a further development of the MiniDisc.

Key takeaways

Hi-MD belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Hi-MD to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Hi-MD from memory before moving on to harder problems.

Reference excerpt

Hi-MD is a magneto-optical disc-based data storage format. It was a further development of the MiniDisc. With its release in late 2004, came the ability to use newly developed, high-capacity 1 gigabyte Hi-MD discs, in the same dimensions as MiniDisc. The last recorder and player was discontinued in 2011. Blank discs stopped production in September 2012.

Overview Hi-MD has several Walkman-selectable audio recording codecs, in order of quality: PCM, Hi-SP, and Hi-LP. Hi-MD Walkmans are backward compatible with MiniDisc playback and most can record. Hi-MD can store computer files and audio data. A bus-powered Hi-MD Walkman is seen as standard USB Mass Storage device with a FAT filesystem. Since the release of Sony's music management program, SonicStage 3.4, virtually all digital rights management was removed for compatible Hi-MD machines. In 2005, Sony announced Hi-MD Photo. The Sony MZ-DH10P Walkman was released to showcase the format with a 1.3 megapixel digital camera. In March 2006, Sony released the MZ-RH1 Hi-MD Walkman in Japan, which was later followed in other regions. With this unit, Sony enabled faster-than-real time transfers from MiniDisc to computers. Sony made tangible speed improvements to the device over previous generations of Hi-MD recorders. The result being that the transfer times to and from computer are—under certain circumstances—cut in half over previous models, but still noticeably slower than flash memory and hard drive-based portables, because of the nature of the Hi-MD magneto-optical system. Some later ("second-generation") Hi-MD devices offered native MP3 support.

Marketing In 2006, Sony positioned Hi-MD as a Digital Audio Tape (DAT) alternative after discontinuing the format the year before, placing the MZ-RH1 Hi-MD Walkman under the Pro Audio section of its "Broadcast & Business Solutions Company" website, alongside its flash memory-based recorder, the PCM-D1. DAT is a high-quality digital tape format that found a niche with musicians and studios. DAT portables have commonly been used for field recording, but have gradually been replaced by solid-state and hard drive-based units like the Aaton Cantar, the Zaxcom Deva, and similar units from Fostex and Sound Devices. The MZ-M200 Walkman is Sony's MZ-RH1 with a stereo microphone included. The MZ-RH1 was targeted to a more general customer on Sony's consumer electronics sites and comes with no microphone bundle. The microphone was included to enable Hi-MD as a field recorder, and the higher price reflects the added value of the microphone. MD had success in Asia (particularly in Japan and Hong Kong), but North America and Europe leaned toward either flash or hard drive-based systems. For professional recording, many offer features such as professional XLR microphone inputs, among other pro-centric features. These units were typically significantly larger and heavier than a Hi-MD Walkman, often with reduced battery life and higher prices. Hi-MD and MiniDisc recorders are no longer being manufactured, but their role has been taken over by relatively inexpensive flash memory based portable field recorders such as the Edirol R-09HR and the Olympus LS-10.

Illustrations

Worked examples

Example 1 — a first encounter with Hi-MD

Start with the simplest possible case. Write down what Hi-MD claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Hi-MD before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Hi-MD ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Hi-MD

In research: Hi-MD appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Hi-MD in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Hi-MD is common in secondary-school and first-year university syllabi. It links to neighbouring topics Audio storage, Audiovisual introductions in 2004, Digital audio, so understanding it makes those chapters shorter.
In everyday life: Look for Hi-MD outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Hi-MD in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Hi-MD means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Hi-MD out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Hi-MD in simple terms?

Hi-MD is a magneto-optical disc-based data storage format. It was a further development of the MiniDisc.

Why does Hi-MD matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Hi-MD?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Hi-MD.