On Saturday, July 23, 2005 @ 3:35 PM, Carlos Robinson wrote:
The Friday 2005-07-22 at 04:15 +0200, Anders Johansson wrote:
And no, I do not accept naming HD memory as RAM memory,
By the way, if you're going to reply to something I wrote, reply to me when I write it.
Sorry, it wasn't meant as an answer to you in particular, that's why that paragraph was indented; it was a "side thought" after reading the whole thread.
I'll reformat the email to recover what I said exactly.
And no, I do not accept naming HD memory as RAM memory, for one thing: it is not directly addressable by the processor, thus it is not even "memory". Reading from HD requires a program, as it resides in a peripheral device. I call it "long term external storage space" ;-)
Notice the smiley, please.
You quoted thus:
for one thing: it is not directly addressable by the processor,
The definition of 'random access' does not include 'direct addressability without the use of a driver'
thus it is not even "memory".
That's just silly
No, it is not.
By "memory" we commonly understand "primary memory". When one goes to the computer shop and ask for more memory, nobody thinks you want to buy a bigger HD.
The common usage of the unqualified term "memory" refers to main memory or primary storage, which has to be directly addressable, its one of its properties. Other uses of the word that are not so common need to be qualified or differentiated.
Therefore, when we talk about "RAM" we are thinking of the memory chips used in computers - even if HD can be considered memory of some kind, it is not what we refer to as RAM. It's the same convention as when we talk of ROM, forgetting that ROM chips are also RAM. A misname, but generally accepted, and we all know what its being referred to.
But this argument is completely byzantine and pointless.
- -- Cheers, Carlos Robinson
Carlos: Lots of good information in your replies. I have saved most of them off. Now at this link -- http://en.wikipedia.org/wiki/DVD-RAM they describe DVD-RAM. To me, this is not really RAM. On the mainframe, we called disk access "direct access" because you didn't have to read through the disk like you did a tape in order to get to the header and then read the data. The catalog (a VSAM file and, as I recall, and ISAM file before that) pointed to the disk volume and the Volume Table Of Contents (VTOC) on that volume then pointed to the beginning of the file. It was direct access but not RAM (you couldn't, as you mentioned earlier, say give me byte nnnn off of the disk). I would say that DVD-RAM should really be called DVD-DIRECT. From my reading of it, it works very much like a hard drive, which, as has been discussed, is not truly RAM. The discussion in the Wiki says that the tracks are laid concentrically as opposed to being one long track, as is apparently the case on regular DVDs. To me, that sounds like a hard drive layout. Am I missing something here, or is DVD-RAM just a poor choice of terms by these folks? Greg Wallace