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Philips’ CDD522 Is Evolution, Not Revolution

Based on technology from the very popular and dependable CDD521 it replaces, Philips’ CDD522 ($3895) should be a sensible interim entry-level recorder until the next generation of double speed half-height mechanisms become available and demonstrate themselves as being stable.

Philips’ CDD522 Is Evolution, Not Revolution

Hugh Bennett
CD-ROM Professional, January 1995

Despite the excitement generated by quadruple and sextuple high-speed CD-ROM recorders over the past year, Philips Laser Magnetic Storage (LMS) is hoping that both the entry-level and professional markets still crave a reliable double speed recorder. Less expensive or faster systems may be available, but cheaper or quicker is not always the point. Philips stresses strong conformance to physical and logical standards with its second generation CDD522 CD-ROM recording unit and succeeds very well in delivering on their promise.

Based on technology from the very popular and dependable CDD521 it replaces, the $3895 CDD522 should be a sensible interim entry-level recorder until the next generation of double speed half-height mechanisms become available and demonstrate themselves as being stable.

The unit records in all industry standard formats (CD-ROM, XA, CD-i, CD-DA, CD Bridge, Multisession, VideoCD, Photo CD) and even supports proprietary sector structures used by SEGA CD and other dedicated game systems. Other features of the new recorder include a large upgradable buffer, true double speed playback and audio transfer through the SCSI bus, future support for disc-at-once recording, and a number of less obvious improvements.

On the surface, the CDD522 is a dead ringer for its predecessor, the CDD521. Philips kept the same large footprint (13.2″ L x 16.5″ W x 4.63″ H x 19.8 pounds) and made only minor cosmetic changes to the case. Two 50-pin high-density SCSI connectors remain on the backplane (right-side-up this time) as well as the bank of DIP switches used for SCSI ID and test mode selection.

Unfortunately, the day of the large case and DIP switch passed at least a year ago. Surely, if Yamaha can produce a credible quadruple speed half-height drive, Philips can manufacture a small double speed mechanism. Few users have enough room on their desks for such a large unit and should not need to look up switch settings when most SCSI devices use a thumb-wheel ID selector.

Included with the CDD522 is a power cord, printed manual, and one 63-minute Philips branded (OEM Taiyo Yuden) blank CD-R disc. Since the recorder uses a tray-loading mechanism, no caddy is necessary. And unlike the older CDD521, the CDD522 is not internally-terminated, so users must add a proper external terminator if the recorder is the last device on the SCSI chain. Other items the user will need to add include appropriate SCSI cabling, host controller, and compatible premastering/mastering software. High-density 50-pin terminators can be hard to find, and many users may end up thinking that Philips should have included one in the package.

A number of companies such as Eastman Kodak, Meridian Data, Inc., Optical Media International (OMI), and Plasmon Data Systems have been using OEM recorders from Philips for several years and are modifying their product line to include systems based on the CDD522.

The $4295 Kodak PCD Writer 225 was first shown publicly at the Seybold San Francisco show in September 1994 and replaces the older model PCD Writer 200 Plus. As with previous units, the distinguishing feature between Philips’ stock recorder and Kodak’s is the ability of the PCD Writer 225 to read unique bar code identification from its Writable CD media. Kodak promotes the serial numbers as being useful for “tracking, indexing, and data security.”

Meridian provides near-complete hardware and software bundles that include the CDD522. Its Personal SCRIBE software version 2.1 now supports the new Philips recorder and Meridian has modified its existing Personal SCRIBE 500P and NETSCRIBE 2020 bundles to incorporate the CDD522. OMI also pairs their QuickTOPiX Windows or Macintosh software with a CDD522, although users must supply the host controller card on the PC as well as appropriate system cabling.

Plasmon Data Systems, on the other hand, took an entirely different approach with their $2995 RF-4100. While Plasmon used some core components from Philips’ recorder, they significantly altered the unit so that it can no longer be considered a CDD522. The most talked about feature of the RF-4100 is its uniquely upgradable ROM. Unlike most recorders (including the CDD522), RF-4100 firmware changes are accomplished through software written to a 128KB EEPROM, rather than having to physically replace chips. Anyone who experienced the endless firmware upgrades on the original CDD521 — which had reached version 2.07 when discontinued — will understand the incredible value of software upgradable ROM.

A number of premastering/mastering software companies indicate that because of strong family resemblances to the older CDD521, the software transition to the new model has been relatively smooth. Certainly, providing support for the Yamaha CDR100 posed greater challenges and took far longer. As a result, most of the major players now have CDD522 compatible programs, or have announced that they will shortly.

The main changes between the older CDD521 and the new CDD522, of course, are inside the recorder. Like all manufacturers, Philips must walk a tightrope, trying to maintain a delicate balance between feature additions and unit cost reduction, so there are both significant and subtle changes and enhancements. Most noticeably, the CDD522 now sports a 2MB buffer that is upgradable to either 8MB or 32MB using pairs of standard 70ns or 80ns 30-pin SIMMS (Single Inline Memory Modules). Philips must be applauded for increasing their standard buffer size and offering unique upgrade capabilities in a mid-level recorder.

Generally speaking, the reasonably swift adoption of CD-R in the marketplace has taken some manufacturers like Philips by surprise. People using the technology no longer have the dedicated and expensive host systems that might be expected of a more “professional” audience, so buffer sizes and buffer-underruns have become significant issues more quickly than anticipated.

Those familiar with the Philips CDD521, JVC, and Pinnacle recorders understand buffer-underruns all too well. In fact, just saying it is often enough to set even the most experienced CD-R user screaming. But, what is a buffer-underrun and why is it such a problem?

A key point to remember about the recording process is that information must be written to a blank disc at a uniform rate (double speed requires a sustained transfer rate of 307.2KB/sec for Mode 1 and 352.8KB/sec for Mode 2 and audio sectors, while single speed calls for 153.6KB/sec for Mode 1 and 176.4KB/sec for Mode 2 and audio sectors). If the rate is not maintained, the disc is ruined.

Unfortunately, a lot of things conspire against a system sustaining an uninterrupted stream of data at the correct rate. Non-dedicated CD-R host computers, slow CPUs, 16-bit peripheral buses, single SCSI chains, hard drives with unruly thermal recalibration characteristics, and on-the-fly ISO recording all contribute to the inability of systems to sustain the required minimum data transfer rate between the host and CD recorder. How the operating system handles very small and large files can also be a problem. Even if none of these issues come into play, any system’s transfer rate will fluctuate wildly—from a few megabytes a second to a few kilobytes a second—and make disc recording impossible.

Therefore, a critical component of any CD recorder is its buffer. Essentially, a buffer is a reservoir of DRAM (Dynamic Random Access Memory) designed to smooth out the variations in the data transfer rate. Like a reservoir which stores water for when it is needed, a buffer stores data for when it is required by the recorder. And as with a reservoir, the guiding principle is to always have enough data in the buffer to satisfy the recorder’s demands, even when the host computer cannot supply the needed amount. If, however, the buffer does run dry (a buffer-underrun), the disc is ruined.

Usually, the larger the buffer, the better the chance that it will never empty entirely, so the CDD522’s standard 2MB cache significantly improves the possibility for success. The prospect of expanding it to either 8MB or 32MB leaves more room for forgiving even greater data transfer sins and opens some interesting possibilities, such as recording a CD-ROM as a background task in a multitasking environment.

Certainly, theory and practice can be completely different things, so the CDD522 was put through its paces under a variety of conditions. Since the characteristics of the original CDD521 are so well known, tests were also conducted against a CDD521 upgraded for comparison purposes. And so that software and host platforms might be eliminated as variables, seven premastering/mastering packages were used (three Windows, four Macintosh), as follows:

• QuickTOPiX 2.0, Optical Media International (Macintosh)

• Easy CD Pro Multimedia 2.12, Incat Systems (Windows)

• Easy CD Pro Multimedia 1.4, Incat Systems (Macintosh)

• GEAR Multimedia 2.4, Elektroson (Macintosh)

• GEAR Multimedia 3.01, Elektroson (Windows)

• CD-IT!ALL 2.5, OptImage (Macintosh)

• WinOnCD 2.13, CeQuadrat (Windows)

The CDD521 has a notorious reputation for buffer-underruns while recording on-the-fly ISO 9660 discs or audio tracks in double speed mode on even the fastest microcomputer systems. The solution has always been to either reduce to single speed or pre-build a physical image file (for ISO 9660) before transferring the source data to the recorder, but that is time consuming, hardware-intensive and clumsy.

During these tests, the CDD522 consistently demonstrated a dramatic improvement over the CDD521. Under identical conditions, the CDD522 wrote discs in double speed mode, which the old recorder could not.

The difference was most apparent in on-the-fly ISO recording. For example, in some cases, a simulated transfer to the CDD521 in double speed mode worked, but the actual recording failed, while the CDD522 had no problems. In other incidents, the host could only sustain the transfer rate necessary for single speed Red Book recording on the CDD521 (whose buffer further reduces to 64K for audio writing), while the data speed was easily sufficient for double speed recording on the CDD522.

Mind Your Ps And Qs
Like Yamaha’s CDR100, the CDD522 encodes P and Q subcode channels, but does not support channels R through W and does not yet write a true disc-at-once format. Philips says they will implement proper disc-at-once recording in a future firmware version and have left the back door open on providing R through W support, depending upon market demand.

Neither the lack of R through W channel support nor writing true disc-at-once format should be a large problem for most users since currently only niche formats such as CD+G require the seldom used channels, and disc-at-once only corrects a few very specific issues. Still, it is curious that Philips publicly emphasizes strict compliance with standards, but only selectively implements them and rushes a product onto the market before fully executing advertised features like disc-at-once.

So, when a company like Philips also preaches the necessity of CD-ROM recorders closely following physical standards, scrutinizing its claims about its own device only makes sense.

Test results confirm that the CDD522 writes a solid disc. Recorded CD-ROMs had no problem being read by a selection of Sony, Toshiba, and NEC CD-ROM drives. In addition, the CDD522 discs passed less forgiving inspection using a CD CATS SA3 system for conducting industrial-level quality control of CDs. Several Verbatim and MTC CD-ROMs were examined for compliance to commonly accepted criteria such as BLER (Block Error Rate), E32 uncorrectable errors, reflectivity, asymmetry, and push-pull. Essentially, discs recorded with the CDD522 suffered from no apparent problems and exhibited the high quality commonly expected from Philips.

Of course, the validity of the analysis is limited to this individual unit and should not be taken as the last word on the CDD522’s recording quality because a statistically valid test would involve a random sampling of recorders and discs from different lots and several sets of testing equipment with different operators. Though only time and further testing will tell the final story, the examination conducted here does provide some reassurance.

As the price of CD recorders declines rapidly, the ability of the devices to write a disc which complies with physical specifications becomes a very important consideration. Many CD-R users have found out the hard way that devices closely following standards can be the difference between being able or not being able to read a finished disc. Recording a CD-ROM is not necessarily the problem—playing it back is. As pressures continue to decrease prices of CD recorders, how far will manufacturers go in cheapening their recorders? It is possible that less expensive mechanisms might cut corners and either not be full-featured or, more dangerously, creatively interpret the physical specifications laid out in the various colored books. This will be a hot topic over the next year as lower priced double speed units enter the marketplace, but for now it looks like Philips has nothing to worry about with the CDD522.

As with all recorders, the CDD522’s performance as a regular CD-ROM drive will not satisfy everyone. Users will applaud its 300KB/sec sustained transfer rate, but are likely to question the 1000ms average access time. Though the drive performance remains limited, the changes are still a vast improvement over the CDD521, which suffered from a playback transfer rate well below 100KB/sec. Another new feature of the CDD522 unit is its ability to transfer audio over the SCSI chain, which is useful for copying or verifying Red Book tracks.

The enhanced read capabilities aid in faster duplication of audio compact discs and CD-ROMs as well as greatly accelerating the speed of disc integrity verification. For products like Meridian’s NETSCRIBE, proper double speed playback also has the advantage of making the device ready for recording more rapidly (since it must go back and read the contents of previous sessions before it can record the next).

Not all premastering/mastering software packages include the device driver necessary for the Philips to function as a CD-ROM drive; check with premastering/ mastering software vendors for this capability.

Philips includes a no-nonsense 66-page manual with the CDD522. It covers basic installation, memory upgrading, and error messages, and includes a concise explanation of the physical and logical structures of CD-ROMs. While all of the basic information is in place, the documentation is definitely not for novices.

There is only a minimal glossary and no index, the explanation of error codes is unclear, the discussion of CD-ROM occurs at a sophisticated level, and installation instructions are too brief.

Inadequate manuals continue to be a problem for CD-Recordable hardware and software products generally, with Philips’ CDD522 maintaining its specific contribution to this problem.

Manufacturers must realize that users and resellers will embrace CD-R more rapidly only if they make the technology more approachable. One obvious and easy way would be to provide simpler, well-written, and adequately illustrated documentation.

Not in the forefront technologically, the CDD522 is still a high quality and reliable recorder and a solid choice for anyone creating CD-ROMs. While some might question its price and physical size, both concerns are relatively trivial when dealing with an emerging process like CD-R.

Confidence in disc and data integrity do not come with hastily designed hardware and rapidly falling prices. Philips has chosen the cautious and trustworthy development approach to lend credibility to its product. Few users can risk the hazards of living on the cutting edge by shaking flaws out of devices that still belong on the drawing board. At least with the CDD522, they have somewhere to turn for a proven solution.

Yamaha’s quadruple speed CDR100 provides stiff (though less predictable) competition for Philips in the higher end, while small double speed recorders about to come from some established and new faces in the first quarter of 1995 will apply pressure from below.

The question will always be, what is it worth to be sure?

Author’s Note: I wish to thank Verbatim Corporation of Charlotte, NC and MTC America of New York, NY for supplying the blank 63-minute and 74-minute CD-R discs used during my review of the Philips CDD522.

Product In Brief

Product: CDD522 CD Recorder

Price: $3899.00

For More Information Contact:
Philips Laser Magnetic Storage (LMS)
4425 Arrowswest Drive
Colorado Springs, CO 80907-3489
800/777-5674; 719/593-7900
Fax 719/599-8713


Software and Hardware Supporting the Philips CDD522

DOS Windows Mac HP9000 SUN R6000 SGI NetWare SCSI
Alea Systems X
American InfoScience X
CD-ROM Strategies X X X
CeQuadrat X X
Dataware Technologies X X X X X
Digidesign X
Eastman Kodak X X X
Elektroson X X X X X
Incat Systems X X
Meridian Data X X
Optical Media International X X
OptImage X
Trace X
Young Minds X X X X X


CD-ROM Recorder Buffer Sizes

Manufacturer Model Buffer Size Notes
JVC XR-W1001 64K
Kodak PCD Writer 600 2MB Buffer expandable to 8MB
Philips CDD521 256K Buffer reduced to 64K for audio
Philips CDD522 2MB Buffer expandable to 8 or 32MB
Ricoh RS-9200CD 1.2MB
Sony CDW-900E 4MB
Yamaha CDR100 512K

Companies Mentioned In This Article

American InfoScience
1948 South IH35, Suite B
Austin, TX 78704
Fax 512/440-0531

Alea Systems, Inc.
5016 Dorsey Hall Drive,
Suite 102
Ellicott City, MD 21042
Fax 410/995-1517

CD-ROM Strategies, Inc.
6 Venture, Suite 208
Irvine, CA 92718
Fax 714/453-1311

CeQuadrat USA
5 Thomas Melon Circle,
Suite 105
San Francisco, CA 94134
Fax 415/715-5610

Dataware Technologies, Inc.
222 Third Street
Suite 3300
Cambridge, MA 02142
Fax 617/621-0307

Digidesign, Inc.
1360 Willow Road, #101
Menlo Park, CA 94025
Fax 415/327-0777

Eastman Kodak Company
343 State Street
Rochester, NY 14650

Elektroson USA
10 Presidential Boulevard
Suite 125
Bala Cynwyd, PA 19004
Fax 610/617-0835

Incat Systems Software
USA, Inc.
1684 Dell Avenue
Campbell, CA 95008
Fax 408/379-2409

Meridian Data, Inc.
5615 Scotts Valley Drive
Scotts Valley, CA 95066
Fax 408/438-6816

MTC America, Inc.
140 E. 45th Street
New York, NY 10017
Fax 212/867-6315

Optical Media International
180 Knowles Drive
Los Gatos, CA 95030
Fax 408/376-3519

OptImage Interactive
Services Company
1501 50th Street, Suite 100
West Des Moines,
IA 50266-5961
Fax 515/225-0252

Plasmon Data Systems
1654 Centre Pointe Drive
Milpitas, CA 95035
Fax 408/956-9444

Trace Mountain Products, Inc.
1040 East Brokaw Road
San Jose, CA 95131
Fax 408/437-3393

Verbatim Corporation
1200 W.T. Harris Boulevard
Charlotte, NC 28262
Fax 704/547-6609

Young Minds, Inc.
1910 Orange Tree Lane
Suite 300
Redland, CA 92374
Fax 909/335-0587

About the Author

Hugh Bennett, editor-in-chief of Hugh’s News, is president of Forget Me Not Information Systems, a reseller, systems integrator and industry consultant based in London, Ontario, Canada. Hugh is author of The Authoritative Blu-ray Disc (BD) FAQ and The Authoritative HD DVD FAQ, available on Hugh’s News, as well as Understanding Recordable & Rewritable DVD and Understanding CD-R & CD-RW, published by the Optical Storage Technology Association (OSTA).

Copyright © Online Inc. / Hugh Bennett