Computer Hard Drive Question

Discussion in 'Computing and Networks' started by nanobyte, Aug 17, 2007.

  1. nanobyte

    Thread Starter Senior Member

    May 26, 2004
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    What type of memory is a computer hard drive known as? RAM or ROM? Or is it even consider one or the other?
     
  2. Dave

    Retired Moderator

    Nov 17, 2003
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    Neither, since it is not random-access nor read-only. A Hard drive is nothing more than a generic name for a non-volatile storage device.

    Dave
     
  3. techroomt

    Senior Member

    May 19, 2004
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    the term random access memory initiated when memory storage devices no longer had to run through a succession of addresses, like that of a magnetic tape or paper tape, to reach the desired address. the address could be selected directly like todays semiconductor IC ram. but yes, the hard drive can be considered a mechanical (long term stoarge) nv-ram device.
     
  4. Dave

    Retired Moderator

    Nov 17, 2003
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    But isn't by definition RAM in the form of IC chips that can access data randomly without movement? Most HDs are of the rotating disk/armature form, hence violating such a definition. Examples of real NV-RAM would be flash drives.

    Dave
     
  5. techroomt

    Senior Member

    May 19, 2004
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    "random access memory" by definition is just that. yes semiconductor memory ic's have adopted the ram tag, but i don't believe ram identifies only solid state devices.
     
  6. Dave

    Retired Moderator

    Nov 17, 2003
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    But we agree that it is rare for the tag 'RAM' to be applied to the modern disk/armature hard drive? Indeed the acronym RAM is so open ended that it can be applied to many memory applications, but addressing the OPs question I would be a touch confused if someone described a HD as RAM.

    Dave
     
  7. cumesoftware

    Senior Member

    Apr 27, 2007
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    Althought not being such a memory, the hard drive as memory behaves like a EEPROM. That is what I can tell you. Of course EEPROMs are different. They are addressable and not FIFO or LIFO.
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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    Strictly speaking, the hard drive is a storage medium. Some confusion may arise from the MSOS using a portion of the hard drive as "virtual memory".

    One might be a bit pissy and define RAM as having the ability to randomly access data in a word-wise manner. Hard drives can get to files randomly, but not to lower levels of data. I suppose it's just possible to write only one word per sector, and meet that definition, though.
     
  9. GonzoEngineer

    New Member

    Jul 8, 2007
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    RAM and ROM are terms reserved for solid state devices.

    A hard drive is totally different, because it is an RMD!

    Repulsive Mechanical Device!:D:D
     
  10. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    I missed that international standards rule. Do you have a cite?
     
  11. Dave

    Retired Moderator

    Nov 17, 2003
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    Considering virtual memory from the OS set, then virtual memory is just that - addressable memory that the programmer can access whether it be physical memory (RAM in many cases) or not. It is one of these abstraction cases which is intended to make programming large software packages easier and more transparent (either that or it encourages bloated software, depending on how you view this!).

    Dave
     
  12. Dave

    Retired Moderator

    Nov 17, 2003
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    Joe, although certainly not a standard, I would hazard to say that it is a convention. NV-RAM typically (in the range of literature on Compouter Systems Architecture) refers to non-mechanical data storage devices where the concept of random is in reference to data locality, i.e. there is no continuum between adjacent data structures. Do Hard Drives satisfy this criterion? This is why physical memory and cache memory are referred to as RAM memory. Sadly these things aren't set in stone and hence raises the doubts we see with the OPs question.

    Dave
     
  13. nanovate

    Distinguished Member

    May 7, 2007
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    You can also add that the time access a piece of information is a constant and not dependent on physical (and logical) location.
     
  14. mrmeval

    Distinguished Member

    Jun 30, 2006
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    "Generally Accepted Usage"

    If there is an official nomenclature I'd sneer at it and start calling it an Alzheimers drive since the things can spontaneously erase as a recent science article stated.
     
  15. beenthere

    Retired Moderator

    Apr 20, 2004
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    That may be electronic indigestion from storing too many bloated MS apps.
     
  16. recca02

    Senior Member

    Apr 2, 2007
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    here is a quote i found on wikipedia hope it solves some of the doubts we have becoz terminologies are not really well thought out or atleast seem to be.
     
  17. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    RAM is an acroynm and as such the flood gates are open, as it describes Random Access Memory, which includes hard drives, sticks of ram, thumb drives, a single electronic chip and a host of any other read/write voltile and non-volitile storage devices.

    GAU ... generally accepted usage ... will get one into trouble.

    I can remember magnetic core non-volitile Random Access Memory in the Digital PDP-8/P computers ... and that ram wasn't a "solid-state" device. Of course I remember phantastron's ... but that only says I'm old. :D
     
  18. beenthere

    Retired Moderator

    Apr 20, 2004
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    Well, there are always mercury delay lines, rotating capacitor arrays, and Johnson tubes.
     
  19. Dave

    Retired Moderator

    Nov 17, 2003
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    Isn't another one the idea of 'memory'. People talk of saving to memory, when they mean the hard disk. In the system of computer architecture, isn't the memory a data storage medium that the processor directly reads to and from (i.e. the RAM)? If so, the hard drive is not memory. The list could go on!

    Dave
     
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