Random Access Tape
Howdy, Group,
Been having a conversation with this guy regarding tape vs disc.
He asked if a hard or floppy disk was more like a tape recorder, or a record player.
sqrfolkdnc' worte, in part: Of course the LGP-30 had main memory AND the accumulator on DRUM, and addresses were NOT sequentially buttigned. While I never worked with an LGP-30, though I helped get...
I'm siding with record player, due to tape's inability to have random access.
I know, record players are WORM drives, and they don't record with metal oxide, but the random access feature seems so important that it outweighs tape's next-bit-in-line way of reading data.
(Or, it's at least *as* important. But in my view, if tape could really have random access, we wouldn't be using the current much more expensive disc drive technology. On another front, imagine the wait time involved in getting to the last sector of a 50 terrabyte file with tape!)
And yes, I understand that a traditional analog record player is actually reading sequentially, (as does tape, further muddying the distinction between the two), but at least it's *possible* to pick up the needle & jump straight to another point on the record. With tape you have to wade through the intervening portions to get to that next read point.
He keeps claiming that tape *can* have random access. Were this the case, of course discs would be more like a tape recorder, as the random vs sequential access argument would be thrown out of the discussion.
Supposing that I am wrong, is there any place one could look to show how tape could have random access?
I don't mean some backup companies sales text *calling* it random, I mean the actual ability for a tape to jump straight from one block to another without moving past all intervening data.
Sure, you can *call* it random if you fast-forward or reverse to the next block, but there are many examples in our society of folks claiming something with one term while it really means another.
I don't agree with that definition. On average one half of a track's medium has to be traversed, and on average one-half of the tracks have...
As a brief example, say you want to go from block 100 to block 200 on a tape device. How could one possibly do that without having to at least go past blocks 101 through 199 on your way?
Given the constraints of three-dimensional space, I just don't see how it can be done.
Any thoughts?
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