CD's vs. DVD's

[Matabiri]

The camera is really good too, the only annoyance is that my iMac doesn't like the 8cm discs, which is a shame because I had hoped to edit the files on the computer. It's a G4 iMac with a Pioneer DVR-104 drive, in case anyone has wise words to offer on this subject.

Isn't there a Firewire/DV out on the camera? You should be able to plug it in and suck the files straight into iMovie or Final Cut or whatever you want to use.

 

[Badly Shaved Monkey]

Isn't there a Firewire/DV out on the camera? You should be able to plug it in and suck the files straight into iMovie or Final Cut or whatever you want to use.

Great idea, it's USB only not Firewire, but...no MacOSX USB drivers for the camera. Maybe they'll appear in due course.

 

[Matabiri]

Great idea, it's USB only not Firewire, but...no MacOSX USB drivers for the camera. Maybe they'll appear in due course.

Have you tried just plugging it in? This works 99 times out of 100 for all devices I've tried on my Mac.

Otherwise it might be worth asking on any reasonable Unix/OSX forum (sorry, can't recommend any), as it's the sort of thing a geek* would probably write for you if asked nicely.

(*The word "geek" is used here in an absolutely non-perjorative way.)

 

[HarryKeogh]

Re: Re: Re: CD's vs. DVD's

I wonder if any group will ever release a "box set" on a single DVD instead of forcing their listeners to deal with a bunch of CDs. With compression a group's entire catalog would fit on a single disc.

I doubt we'll see it. It seems that when people shell out 50 bucks (or whatever amount) for a boxset they want a lot of disks. Makes them feel like they are getting their money's worth.

I find it annoying that there are so many DVD boxsets (particularly TV shows on DVD) that put a season of shows on 4 or 5 discs when they could fit on 1 or 2.

Guess it also has something to do with shelf space and getting your product noticed.

 

[Badly Shaved Monkey]

Have you tried just plugging it in? This works 99 times out of 100 for all devices I've tried on my Mac.

This is the 1 in 100, I'm afraid

Otherwise it might be worth asking on any reasonable Unix/OSX forum (sorry, can't recommend any), as it's the sort of thing a geek* would probably write for you if asked nicely.



Good idea.

 

[rppa]

Re: Re: Re: CD's vs. DVD's

Pet peeve: the use of "memory" for permanent storage. "Memory" goes away when the power is off.

How did that get decided?

Well, it's not the "going-away" part that makes it memory so much as that memory is a fast, random-access storage area that is integrated with the CPU. Running programs are things sitting in memory. A CPU runs an instruction, grabs the next thing in memory, runs that, if the instruction tells it to go somewhere else it goes to THAT place in memory.

In most computers, the thing wired into the CPU this way is usually a bank of RAM chips, which have the property that they use the power supply to keep the state of the 0's and 1's they keep track of. Your computer boots off another memory chip containing read-only memory (ROM) which isn't volatile: it's storage stays when the power goes off.

So maybe it makes more sense to define "memory" as "the addresses used by the CPU". Storage like a disk, a tape, or a CD is something completely different. If you want to run a program stored on one of those things, you have to first copy it into memory. If your program wants to read or write data to those things, it does it by first putting it in memory. Memory is the thing that's directly accessible to the CPU. Storage is indirect and therefore slower.

Memory sticks would seem to blur the issue, since they contain memory chips. But they pretend to be storage. The CPU can't read them directly, it treats them like disks and has to do the same copying through memory that it would in reading any other storage device.

More than you wanted to know.

 

[Matabiri]

This is the 1 in 100, I'm afraid

Foo!

 

[Art Vandelay]

Well, it's not the "going-away" part that makes it memory so much as that memory is a fast, random-access storage area that is integrated with the CPU. Running programs are things sitting in memory.

I'm familiar with the basics, but it's the reason for the nomenclature that I'm wondering about. Is there some clear reason why "memory" is not an appropriate term for storage, or did it just develop that the term was reserved for RAM?

Storage like a disk, a tape, or a CD is something completely different. If you want to run a program stored on one of those things, you have to first copy it into memory. If your program wants to read or write data to those things, it does it by first putting it in memory. Memory is the thing that's directly accessible to the CPU. Storage is indirect and therefore slower.

Is storage slower because it's indirect, or is it indirect because it's slower? If one wanted to build a computer where the CPU directly queries the hard drive, wouldn't that be possible? I thought that the reason this is not done is because it would be so slow, not because it's impossible. And is memory really accessed directly? I thought it's copied to the registers, and processed there.

With processor speed now making it impossible to put RAM within a clock cycle of the CPU, and caches now being larger than the entire RAM of earlier computers, do you suppose that the term "memory" will shift to referring to the cache, and RAM will become "intermediate storage"?

The CPU can't read them directly, it treats them like disks and has to do the same copying through memory that it would in reading any other storage device.

I take it than unless a special system is set up, when you network a bunch of computers together, each computer treats memory in every other computer as storage? Is there "virtual storage", a counterpart to "virtual memory"? For instance, if you tryconnecting 5 GB of memory to a 32 bit processer, you wouldn't be able to address the last GB, right?

 

[El Greco]

Is storage slower because it's indirect, or is it indirect because it's slower? If one wanted to build a computer where the CPU directly queries the hard drive, wouldn't that be possible? I thought that the reason this is not done is because it would be so slow, not because it's impossible.

Probably you're right, but the whole architecture is based on the existence of memory. Computers started without permanent storage, so...

And is memory really accessed directly? I thought it's copied to the registers, and processed there.

Not necessarily. There are also instructions which directly manipulate memory. Sometimes it's faster, others it's better to copy to a register and proceed from there.

With processor speed now making it impossible to put RAM within a clock cycle of the CPU, and caches now being larger than the entire RAM of earlier computers, do you suppose that the term "memory" will shift to referring to the cache, and RAM will become "intermediate storage"?

I think that "memory" will always refer cumulatively to what's lost when there's no power.

Is there "virtual storage", a counterpart to "virtual memory"? For instance, if you tryconnecting 5 GB of memory to a 32 bit processer, you wouldn't be able to address the last GB, right?

I'm not sure what you mean by virtual storage. RAM drives could be something like this but generally "storage" is a priori not virtual. With 5GB of memory you couldn't access the last GB directly, but you could map it to some lower memory locations and access it indirectly, something like a selector : offset pair. That is, you could design a system that uses two 32-bit registers for accessing memory.

 

[RussDill]

I'm familiar with the basics, but it's the reason for the nomenclature that I'm wondering about. Is there some clear reason why "memory" is not an appropriate term for storage, or did it just develop that the term was reserved for RAM?

It makes it easier for computer people to communicate if they segment terms out. Memory is really a black box term that refers to a large, flat space where you can store things. It could be implemented via an SPI interface, it could be SRAM, DRAM, mercury tubes, etc.

Is storage slower because it's indirect, or is it indirect because it's slower?

Its slower for physical reasons. Compared to the processing speed of the CPU, and speed at which RAM can be accessed, the hard disk takes a very, very, very long time to make one revolution.

If one wanted to build a computer where the CPU directly queries the hard drive, wouldn't that be possible?

Yes, but it'd be slower. Because the cpu doesn't operate in the time scale of the hard drive, its much better just to put a request into a request queue, have the hardware carry out the requests, and be notified when they are complete. In that way, the cpu can go about its buisness doing other tasks.

I thought that the reason this is not done is because it would be so slow, not because it's impossible.

Many older computers functioned in this way, simply because the OS and hardware was not advanced enough to take advantage of cpu offloading.

And is memory really accessed directly? I thought it's copied to the registers, and processed there.

It depends on the CPU architecture. Many architectures access memory directly (like x86). But modern ones do not, they load registers first. Also, whenever you are accessing memory, you are usually accessing a cacheline that is loaded with that memory.

With processor speed now making it impossible to put RAM within a clock cycle of the CPU

Actually, no, older processors, the cpu and ram functioned at the same clock speed. But with modern processors, the cpu functions at a much, much higher speed. When any access is made, the processor bursts a larger amount of data from the RAM into cache, then, when more data is accessed, the data will hopefully already be in the cache.

and caches now being larger than the entire RAM of earlier computers, do you suppose that the term "memory" will shift to referring to the cache, and RAM will become "intermediate storage"?

naw, like I said before, memory is really a programmers definition, they don't care how its implemented.

I take it than unless a special system is set up, when you network a bunch of computers together, each computer treats memory in every other computer as storage?

afaik, distributed NUMA (non-uniform memory architecture) systems exist.

Is there "virtual storage", a counterpart to "virtual memory"? For instance, if you tryconnecting 5 GB of memory to a 32 bit processer, you wouldn't be able to address the last GB, right?

Virtual memory is the amount of memory in your memory map. When you load a program, or file, it is mapped into virtual memory. If you don't have enough RAM to hold it, thats fine, it just pages from the disk when it needs certain parts of the file. Swap is done in a similar fashion. Thus, the 4GB limit becomes a problem even if you don't have 4GB of ram, because you virtual memory is limited to 4GB.

Using more than 4GB (or 3GB, depending on the architecture layout), is usually done by giving each individual process a 4GB memory map.