With new wave of CD-ROMs, spin speed varies on disk locale








CD-ROM speed claims remind me of the childish taunt, “My daddy can beat your
daddy.”


I have complained before that 24X, 32X or faster drives don’t operate in real life
much better than old 2X or 4X drives [GCN, July 27, 1998, Page 49]. That’s because
the new drives are variable-speed and spin slowly near the center. They only reach the top
rate at the outer edge. And because CDs are written from the inside out, you never see the
advertised speed unless the disk is full.


The same column mentioned multibeam technology that promised high-speed access to all
parts of a CD. Kenwood Corp. of Cupertino, Calif., now makes a multibeam 52X drive, and I
put one through its paces.


Although I didn’t see 52X across the entire disk, the drive was significantly
faster than the fastest variable-speed


drives I have used, from a minimum 48X to a true 52X. Installation was a breeze; I just
pulled the CD drive from a Pentium PC and connected the Kenwood. Microsoft Windows 95
recognized it.


Although the drive spins disks faster than early 1X drives, it’s far slower than
other 50X drives. It gets most of its performance boost from splitting the pickup laser
beam across seven adjacent tracks. Because it turns more slowly than other drives, it is
more forgiving of old CDs that new drives cannot read.


To use its potential, you need a fast Pentium system with SCSI or Enhanced IDE
bus-mastering and Windows 95 OSR2. The price is about $100, making the Kenwood a
reasonable upgrade.


For users who work in multimedia or query large databases on CD-ROM, this drive will
transfer a minimum 6.75 megabytes of data per second. On average, I got nearly
7.5-megabyte/sec transfer rates across the entire disk, compared with about half that for
other fast CD-ROM drives.


Average access time was a moderate 90 milliseconds except for single large files or
adjacent files within the seven-beam band, where I got a terrific 5 ms.


Other advantages of slower disk spin are quiet operation and the elimination of spin-up
time that makes so-called 50X drives little faster overall than ancient 2X drives.


The 52X Kenwood TrueX UCR-412 ATAPI drive I installed, and an earlier multibeam 40X
Kenwood drive, are compatible with all CD formats. I’m betting multibeam technology
could be pushed to higher performance, although that might cut into its present ability to
read old CDs.


Visit www.kenwoodtech.com for more
information. 


Lower the screen, turn on the projector, dim the lights, turn on the microphone, turn
on videocassette recorder 1, turn off VCR 1, switch input to the laser disk, turn it on,
turn it off, raise the screen and turn the lights back on.


A presenter can fumble trying to keep up with such complex physical switching demands,
let alone remember what to say. One remedy is a preprogrammed infrared remote controller,
but then the presenter must remember which device to switch and which switch does what,
all in the dark.


My presentation center has two VCRs, a projection TV, a smaller TV, a satellite
receiver, a broadcast antenna, a security camera, three audio amplifiers, a CD player, an
AM/FM radio and a VGA-to-TV link, all fed through various cables.


To manage this monster, I use two handheld infrared remote controls—the kind
programmed from existing controllers. Both let me program 10-step or longer macros for
each key. I can mix and match commands between different devices, push a single button to
change lighting levels, turn on a TV, switch on a VCR, adjust the level of a sound system
or feed audio to an intercom system.


I found one 24-button programmable remote for about $60 at Home Automation Systems Inc.
of Irvine, Calif., at www.smarthome.com. The other, priced around $190, has a backlit LCD
touch-screen with programmable virtual buttons. You can assign functions or macros to each
of the 28 virtual keys on each of the eight menu pages.


The permutations are mind-boggling, but remember that you can preprogram multiple
functions on different screens or a single screen. At show time, you only have to remember
to push one button for each new sequence.  


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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