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tuhdo / os01

Bootstrap yourself to write an OS from scratch. A book for self-learner.
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SUGGESTION: Modern Storage Devices #36

Open jstaursky opened 7 years ago

jstaursky commented 7 years ago

Let me first say that I really like your book and its presentation style that does not lose sight of the Forrest for the trees. In particular I really like the autodidact approach and starting from first principles. With that in mind I thought the mention of storage devices on pg 22. could have used a little more of this kind of treatment rather than saying "...the modern devices are so complex that is is impossible and unnecessary to understand every implementation detail.." Rather than say that I propose a quick hi-level summary along the lines of ..

"Modern Storage Devices are implemented by injection of an electron into a material which is held and retrieved from said material by the opening and closing of potiential barriers that exist by virtue of the materials elemental properties and are manipulated by applying a voltage across the two materials. The materials involved will affect the response and retrieval times as well as the memory's fastidiousness in holding the charge over time. The details of this process can be found in any introductory Solid State Theory Textbook."

...While admittedly that is quite terse and probably could use some rephrasing, it does capture the basic gist of it without going into details of quantum mechanics or any talk of valence bands, etc.

Another approach might be to rephrase the above into an analogy along the lines of hungry hungry hippos where the electrons are the balls traveling along the conductive path / BUS and the opening and closing of the hippos mouth be the barrier / oxide and the inside of the mouth be the potential well of the receiving substrate. The players fingers which activate the hippos mouth would be the applied voltage. If you need more detail, I would say the best intro to solid state physics would be https://www.amazon.com/Semiconductor-Device-Fundamentals-Robert-Pierret/dp/0201543931/ref=sr_1_1?s=books&ie=UTF8&qid=1487522457&sr=1-1&keywords=semiconductor+device+fundamentals

Whether or not this is a worthwhile digression (maybe in an appendix?), I think this would help maintain the "from basic principles" approach.

tuhdo commented 7 years ago

The original sentence is meant to emphasize abstraction since a modern complex device, such as a CPU, is implemented by multiple different teams, so it's unlikely someone understands the implementation of a CPU. So, it's useful to study only the interface to use the device.

However, such info would be a nice addition.