Quote:
Originally Posted by jswinden
How about saying "built-in or onboard storage" and SD card storage. You are absolutely correct about RAM not being onboard storage. I used the wrong term. My bad.
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A lot of our embedded controllers stored their configuration in RAM chips that had built-in lithium batteries. But some needed replacing after 10 years or so in some machine tools. So even RAM is often used for long term non-volatile storage. MMC (and other flash memory) chips are a lot higher capacity and cheaper (and surface mount), so it is more popular these days. I recently had to get a free sample battery-backed RAM chip to replace the one in my thermal camera, so I do not have to reconfigure it every time I turn on the power. There is no clear boundary between memory and storage, but in general usage, memory is a subset of storage. "Onboard" is not a clear distinction either, because the SoC (system on chip) used in the kindles contains both volatile and nonvolatile memory storage (RAM/ROM and programmable permanent storage).
SD card storage is a clear distinction though (up to a point). Even onboard chips can use the same communications protocol as an SD card, so from a programmer's perspective it is the same thing. MMC memory storage is available in both onboard chips and in removable SD-card format. Before SSDs (solid state drives) became affordable, external high-speed backup storage could be purchased that contained a large quantity of battery-backed RAM chips.
All I am saying is that it is not safe to make an absolute statement that there is any clear distinction between memory/storage or onboard/external. They are just different implementations of the same thing (with the exception that storage can also contain physical objects that do not represent information).
EDIT: Okay, fine. Be happy with your absolute belief in absolute definitions, despite a ton of technical literature that uses these words in very non-absolute and conflicting ways, and a lot of real hardware that also crosses any artificial boundaries you have defined.