Honest-to-goodness increases in CD-ROM drive speeds are near
CD-ROM technology is the subject of two books I've written, and I rely on it for much of my research, archiving and backup. So heed what I say: 24X, 32X and other variable-rate CD-ROM drives are hardly any faster than a single-speed 8X drive. They achieve peak performance over only a tiny portion of the 550M disk media.
CD-ROM technology is the subject of two books Ive written, and I rely on it for
much of my research, archiving and backup. So heed what I say: 24X, 32X and other
variable-rate CD-ROM drives are hardly any faster than a single-speed 8X drive. They
achieve peak performance over only a tiny portion of the 550M disk media.
Even the older, single-speed CD-ROM drives run at variable rates because they move data
past the read laser at a constant speed. A drives spin rate at a particular time
depends on how far out from the center of the disk the pickup laser is located.
A variable-speed drive is even more complex. It reaches advertised maximum read speed
only at the disks outer edge and then only occasionally, because CD-ROM disks are
seldom full. They get written from the center to the outside, and the data usually runs
out short of the edge.
A new development on the horizon, however, could boost CD-ROM performance to remarkable
heights and for only about twice the already low cost.
The concept will sound familiar to readers who have followed hard drive technology over
the years. Remember when companies were desperate to improve hard drive performance and
began to put multiple read-write heads on the same platter? The same thing can be done on
CD-ROM drives, which ordinarily have a single laser beam.
What if you put 10 beams on a single-speed drive running at 10X? Wouldnt it give
true 100X performance while spinning the disk at only 10X speed?
Several companies are working on it, and I expect to see 100X CD-ROM drives announced
or even on the market by the end of this year if not sooner.
An Israeli company, Zen Research NV, has so-called TrueX technology, which consists of
a controller chip and multiple laser beams that accelerate CD-ROM and digital video disk
drives to 41X or faster retrieval rates. See the companys Web site at
http://www.zenresearch.com. The U.S. office of Zen Research Inc., is in Cupertino, Calif.
Kenwood Corp. of Tokyo claims to have the worlds fastest CD-ROM drive, designated
the Z40X. Its supposed to deliver 40X speed across the entire disk, not just the
edge. The domestic headquarters for Kenwood Communications Corp. is in Long Beach, Calif.
The Z40X, based on Zen Research work and not yet available in the United States, spins
at constant linear velocity. Combined with the multiple pickups, it could give 300 percent
faster overall data access than the fastest variable-speed drives.
I look for 40X and faster CD-ROM and DVD drives to flood the market by the end of
1998assuming they work as claimed.
Heres a brief update on Matlabs Image Processing Toolbox from Mathworks
Inc. of Natick, Mass., part of a math program that I reviewed earlier [GCN, Feb. 23, Page 36]. Math programs not only crunch
numbers, they also can do digital image processing.
I recently tried out Matlabs IP Toolbox 2.0 and found that it worked faster and
had more than 100 new functions for images from astronomy, remote sensing and microscopy.
For users interested in maps, the MatLab mapping toolbox can show contour data and
create more than 60 map projections. The package comes with astronomical, world and U.S.
atlas databases.
MatLab software can process data available from commercial sources as well as
government Web sites such as http://www.usgs.gov/, http://www.census.gov/ and http://www.nima.mil/.
Examples of what you can find on the National Imagery and Mapping Agency site include
Digital Terrain Elevation Data Level 0 maps and data covering most of the world in
1-degree cells.
This unclassified data comes from the Defense Departments gigantic classified
archive of terrain data.
You can view the raw data from the CD-ROM library, download it in compressed format or
use a Java applet to view the elevation data directly on-screen in 3-D.
At the NIMA site, check out NIMAMuse 2.1, NIMAs downloadable freeware suite for
mapping, charting and geodesic data. It runs on platforms from Microsoft Corp., Silicon
Graphics Inc. and other companies.
NIMAMuses Fusion application, one of many in the suite, builds maps by fusing
vector and raster data. You must register and get a password before downloading the
software.
The entire package of self-extracting executable files is 5.5M, not counting the
separate documentation. Although it lacks the support and polish of a commercial mapping
program, it might be just what you need, and the price is definitely right.
John McCormick, a free-lance writer and computer consultant, has been working with
computers since the early 1960s. E-mail him at powerusr@penn.com.
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