🚀 go-pugleaf

In <44671@ucbvax.BERKELEY.EDU> chiueh@sprite.Berkeley.EDU (Tzi-cker Chiueh) writes:
| I have two questions on tape drives. Hope someone on the net can enlighten me.
| 
| 1) Although tapes are cheap, but tape drives are more expensive than disk drives.

It isn't, except for the very smallest disks, or the most expensive tape
drives (most 9 track's, for example).

|     Why is this the case? Also could someone tell me what is the breakdown of a
|    tape drive's cost. For example, the tape transport mechanism, the R/W head, 
|    and the A/D & DSP elctronics.
| 
| 2) The "position angle" of a tape head with respect to a tape in 4mm and 8mm 
|    tape drive is 90 and 200+ (?) degrees, but is 0 degree for linear scan tapes.
Yes, it is the difference between helical scan and linear drives.  The
helical scan moves the tape slowly, but has a rapidly rotating head
(on a drum).  It makes the tape transport simpler and more reliable (in theory)
for a given data density.

|    Also, does this mean that for 4mm and 8mm tapes, the head must touch the tape
|    during read/writes?

Yes, which is also the case for QIC.  Well, it doesn't actually touch
the *head* (in either case), but it contacts the 'shell' around the
heads.
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Let no one tell me that silence gives consent,  |   Dave Olson
because whoever is silent dissents.             |   Silicon Graphics, Inc.
    Maria Isabel Barreno                        |   olson@sgi.com