Readable and rewriteable CD-ROM

The tables are turning in storage device technology as vendors look to CD-ROMs as a storage solution. CD-ROMs have a higher capacity and a larger installed support base than other removable media. Also, standards exist for rewriteable CD-ROMs, including the MultiRead standard and the rewriteable standard, CD-ReWriteable (CD-RW).

HP offers CD-ROM storage technology that may become the basis for the digitized storage medium of tomorrow. HP's technology has its fair share of kinks. However, the gee-whiz factor of using Explorer to write to, erase from, and rewrite to a CD-ROM as if it were a floppy disk smoothes those kinks a little.

HP's SureStore CD-Writer is a CD-RW drive that comes in two versions: an internal IDE unit connects to the hard disk's cable, and an external unit connects to a machine's parallel or printer port. I tested the external drive, HP SureStore CD-Writer Plus 7110e. The unit's pass-through parallel port on the back means you won't need to plug and unplug devices every time you print or access the CD-RW drive. But note that when you use an external unit, writing to the silver-coated CD-RW media and printing simultaneously will slow your machine.

Both designs (internal and external) can read CD-ROM, CD-R, and Digital Video Disc (DVD) at 4x speeds. Both designs can write at speeds of up to 2x, depending on processor power, memory, and the target file's location (e.g., hard disk, CD-ROM, or floppy).

One big complaint about CD-RW technology is that the CD-RW discs are not compatible with most of the installed base of CD-ROM devices. To address this concern, the 7110e can write to standard CD-R media in addition to CD-RW media. The CD-Rs produced by the 7110e are backward compatible and most CD-ROM and CD-R devices can read these discs.

The CD-R Media
Once you use 7110e to write to CD-R discs, you cannot erase them, but you can write data in separate sessions. This option lets you add numerous files to a disc without writing them all at once.

When writing to a CD-R, the 7110e occasionally stalled on particular files. To copy these files, I had to select the file and drag it to the drive letter corresponding to the 7110e. If you're copying a whole disc or program, this method quickly becomes annoying. And if you don't manually copy the file that stalls the recording session, your program might not function correctly, which renders the CD-R media useless.

When you've copied all the information to the CD-R disc, you must use the supplied Adaptec DirectCD 2.0 software to close the disc. After you close it, you cannot write to it. And the CD-R discs I recorded with the 7110e worked only in the CD-ROM drives of the new machines in the Lab; the older a CD-ROM drive, the less likely it was to read the 7110e's CD-R discs.

The CD-RW Media
The CD-RW disc provides the same 650MB of storage as a standard CD-R disc, but the data is more flexible. Before you can work with a new CD-RW disc, you must use the Adaptec DirectCD 2.0 software to format it, as Screen 1, page 94, shows. Formatting is time consuming, taking from 50 minutes to 90 minutes. After the formatting, you can erase and write to the disc by simply dragging files in Explorer or directly sending files to the disc from applications.

Any CD-ROM drive adhering to the MultiRead standard will support the CD-RW media. An HP technician claimed most 24x speed CD-ROM drives also support the CD-RW media, whether they carry the MultiRead logo or not. However, in my testing, I could not HP SureStore CD-Writer Plus 7110eget 24x CD-ROM drives to read the CD-RW discs I wrote with the 7110e regardless of the drives' MultiRead certification.

The CD-RW media are forward compatible with the DVD drives because of the similar reflectivity of the chemical composition, or substrate, on the CD-RW disc. HP uses this substrate to store data on CD-RW and DVD optical discs. The reflectivity of typical CD-ROM discs is about 70 percent; of CD-R discs, it's about 65 percent; and of CD-RW and DVD media it's between 20 percent and 25 percent. For CD-ROM drives to read CD-R media, you must tone down laser sensitivity. Consequently, MultiRead devices need to adjust for each end of the reflectivity spectrum. The similar reflectivity means a DVD device can read CD-RW media and the 7110e can read a DVD data disk.

A Blue Day
When I installed the 7110e's software, my machine displayed a blue screen, which reminded me of the benefits of an updated Emergency Repair Disk (ERD). Before you install a 7110e and its software, update your ERD, run a scandisk and checkdisk (cross-linked chains and 7110e can wreak havoc on a hard disk if conditions are right), and update your disaster recovery scenario.

I moved the device to another NT workstation and installed it. This experience was much better. However, occasionally, when I dragged a folder toward the drive letter associated with 7110e, my machine took a blue-screen nosedive. Fortunately, I resuscitated this machine with just a reboot.

When I moved the device to yet another NT workstation, it ran flawlessly every time. In our lab experience, devices connected to parallel ports in NT are notorious for causing problems. For this reason, I recommend you buy the internal version of this product, which is about $100 cheaper.

With a recording speed of 2x (roughly 300Kbps) and a read speed of 4x, the 7110e's performance won't blind you. The device took about 9.5 minutes to write a 100MB test file to the CD-RW disc, which works out to a little better than 10 Megabits per minute (Mbpm). This performance is nothing to write home about because the average tape device runs at 60+Mbpm. I hoped the internal IDE device's throughput would be better when writing to a disk, but an HP representative told me that both units write at only 2x speeds.

If you're hoping that a faster SCSI version will be out soon, don't hold your breath. The limit on recording speeds isn't caused by a throughput bottleneck but by jitter and bler, the quality assurance parameters, associated with CD-ROM recording. When the laser writes to a disc, it can't move too much (jitter), or the information will be distorted (bler). Because writing must be more accurate than reading (information can be reread if the laser misses it), the laser must go slower when writing to ensure a clean, accurate burn. If you open the device, you see the laser wrapped in a lead enclosure to assist its stability.

HP's 7110e has downfalls. It is particular about which media it will write to, and older CD-ROM drives can't read the CD-R or CD-RW media the unit produces. It's pokey when formatting CD-RW discs, reading media, and writing to a medium. Worse yet, the 7110e wiped out my desktop machine. But despite the flaws, I love this device. I want one.

HP SureStore CD-Writer Plus 7110e/7110i
Contact: HP 800-752-0900, Web: http://www.hp.com
Price: $610 for external model (7110e); $499 for internal model (7110i)
System Requirements: Windows 95 or Windows NT 4.0 with at least SP2 75MHz Pentium 16MB of RAM 5MB free hard disk space for installing software; 10MB available space for each minute of recorded music High-speed serial port set to IRQ 7 and I/O address 378 or IRQ 5 and I/O address 278