Random Access Tape 2463

Please don't toppost. I've fixed it for you...once.

Not quite. There is the physical geometry and then there is the paths the heads have to travel before getting to the location where the data is stored. I think you also are confusing the two "geometries". I can't recall the term used for the actions needed to get at a location.

It's not clear to me what your friend is trying to teach himself. I'll hazard a guess that he's trying to distinguish a "one-way" device with an "any-way" device. With most magtapes to get at any set of bits, you started at the beginning of the tape and kept reading until you hit what you wanted. If the next set of bits were located "earlier" on the magtape, one had to rewind the tape to beginning of the tape and start all over even if the bits you wanted were at the end of the tape.

With a disk or floppy, there are round circle of "tape"; each circle has a diminishing diameter. So getting at a location is "faster" because the disks can start at the point where the last access was done. There are two "ways" these devices can physically travel to get from here to there; it's rather like walking around a city on an island whose roads intersect.

I can't tell you a thing about how CDs work; those critters are magic spinning saucers to me. :-)

Note to others: something just exploded outside; sounded about a block away and the lights flicked. I may not be online later.

BAH