29 Jul
2020
29 Jul
'20
8:29 p.m.
On 2020-07-29 15:17, Paul Koning wrote:
True. But seek times are in the end only relevant as an aspect of the
speed of the thing, nothing else.
However, seek times on DECtape aren't really comparable to magtape
either. Because DECtape deals with absolute block numbers. So you can
always, no matter where you are, find out where you are, and how far you
will need to move to get to the correct block.
With magtapes, this is pretty much impossible. You'll have to rewind,
and then start seeking.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt(a)softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
On Jul 29, 2020, at 5:50 AM, Johnny Billquist
<bqt(a)softjar.se> wrote:
Just a small comment. Whoever it was that thought DECtape was a tape was making a serious
mistake. DECtapes are very different from magtapes.
Johnny
Depends on what you're focusing on. Most tapes are not random-write. DECtape and
EL-X1 tape are exceptional in that respect. But tapes, DECtape include, have access time
proportional to delta block number (and that time is large) unlike disks.
From the point of view of I/O semantics, the first point is significant and the second
one not so much.