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DataZoneThe Return of Removable Hard Disk Drive Architecture

white paper:- by Steven L. Kaczeus - DataZone - August 2000

Many people don't realize that the founding fathers of the Winchester disk drive at IBM Corporation originally mandated that the computer's primary storage device, the magnetic hard disk drive, was to be removable. This requirement was necessitated by application demands to interchange digital files with computer mainframes, to backup data for security, and to archive information and libraries for extended periods of time. IBM executives in their overzealous confidence, stopped manufacturing tape drive systems because removable disk drives would serve as backup/archival storage systems and there would be no need for inferior tape storage media.

Conditions changed when IBM introduced the Model 3350 disk drive, which had eight platters and weighed over 50 pounds. This was the only way IBM could achieve a 314MB storage capacity at that time. Thus, the removability requirement was abandoned and the first fixed hard disk drive was born.

In 1980, Seagate Technology became the first company to introduce and manufacture disk drives for the personal computer industry. Since the disk drive was fragile and sensitive to shock and electrostatic discharge conditions, the product was hidden within the computer system and has remained fixed as an industry standard even today. In the last two decades, areal density of the disk drive has increased ten thousand-fold and the price per megabyte has decreased one thousand times. In comparison, if the automobile industry had made similar progress in the same time period, today we would have a car that would run 100,000 miles on a gallon of gasoline that would cost only $30.00. The customer would never have to stop at the gasoline station during the life of the car. In spite of the phenomenal technology progress, the disk drive's fragility specification has not improved at all. Even today, a one-inch drop onto a solid surface will permanently damage a disk drive and the resident data on the drive will be lost. As a result, the disk drive is still protected inside the computer housing and many users have never seen a disk drive in actual shape and form.

Disk drive fragility has a dramatic effect on overall data loss in the industry and is a primary reason for data backup. Statistical data shows that shock and physical abuse of computers represent 44% of all data loss. Data loss associated with notebooks and portable computers is even more drastic. Statistics show that 8% of all portable devices are damaged every year with an average hardware repair cost of $1,200. With 50 million notebooks in circulation worldwide, this represents an annual hardware loss of $4.8 billion and the value of lost data is not even included in this number.

Since computer architecture is standardized on fixed disk drives, data exchange, backup, and archival applications have been delegated to other peripheral devices such as floppy disk drives, CD-RW, DVD-RAM, tape drive systems, and cartridge-based drives such as the Iomega JAZ or Castlewood ORB. None of these products compare in capacity, performance, or price per megabyte to that of the hard disk drive (see figure 1), but until now, there was other convenient solution available on the market.

removable storage
Removable disk drives on
Targa Series 4 - 2.5 inch SCSI flash disk
Removable Military Solid State Disks
from Targa Systems
Teralyte removable disk to disk backup for SMBs
ejectable disk to disk backup for SMBs
Teralyte from Idealstor
rugged external disk drives from Olixir
rugged USB 2 external backup HDDs
from Olixir Technologies

Figure 1 - A Comparison of Removable Storage Devices




Jaz 2


Zip 250






SureStore DAT8


6, 12, 18, or 25GB

2GB per cartridge

250MB per cartridge

2.16GB per cartridge

5.2GB per disc

8GB per cartridge


Burst Transfer Rate*







Access Time






40 second search

Rotational Speed

4200-5,411 RPM

5394 RPM

2941 RPM

5400 RPM

1024 – 2387 RPM



Non-operational Shock






Not available

Acoustic (Operating)

30 dBA

42 dBA

<32 dBA (Zip 100)

<36 dBA

<45 dBA

Not available


12 oz.

2 lbs.

8 oz.

15 oz.

6.61 lbs.

5.5 lbs.

Interface Options

External device

Parallel Port


Parallel Port

Parallel Port



Internal device

AT/IDE in DataBay








2 years

1 year

1 year

1 year

1 year

3 years


$299 for: 6GB external drive and software

$649 for: external drive and 3 cartridges

$720 for: External drive and 24 cartridges

$259 for: external drive and 3 cartridges

$ 993 for: external drive and 1 DVD-RAM disc

$917 for: external drive and 10 cartridges

*The burst rate is for an internal device. Transfer rates of external devices are limited to the throughput capacity of the interface used and not the device itself:

Typical Transfer Rates by Interface

PCMCIA = 2MB/second

USB = 1.5MB/second

Parallel Port = .8MB/second

Today, in August 2000, DataZONE offers the opportunity to configure the personal computer with a removable hard disk drive as the original disk drive designers at IBM mandated with its DataBook portable hard drive. DataBook offers entry-level capacities from 6 to 25 GB with an incredible non-operational shock specification of 10,000 G, which is equivalent to a 30-inch drop onto a concrete floor. Current desktop hard disk drives typically have only a 200-G shock rating which is equal to a 1-inch drop. With DataZONE's proprietary technology, the hard disk drive is now the most durable and rugged peripheral in the industry. Additionally, DataBook is compact and lightweight (the size of a paperback book), operates at low power (5 VDC only), and has the lowest acoustic emission in the industry making this device perfect for audio/video applications. The DataBook interface is a standard AT/IDE 36 pin connector (data lines and power supply included) and interfaces to a desktop and notebooks through numerous interfaces including Parallel Port, USB, Firewire, PCMCIA and DataZONE's DataBay docking module. Inserting a DataBook into the DataBay allows the unit to run at internal drive speeds achieving transfer rates of up to 66MB/second. Hot-Swap software is an optional feature for users requiring frequent data exchange or for applications that won't allow for the computer system to be shut down temporarily. Beyond DataBook, the DataBay housing interfaces with the standard IBM Travelstar E series of disk drives and, in the near future, other companies will offer DataBook equivalent disk drive products. With the proprietary disk drive technology offered by DataZONE, removable disk drive architecture is resurrected and the personal computer can be architected to the original Winchester technology brilliance (see figure 2).

Figure 2

Now that portable disk drives are real and readily available, the potential applications are endless. For example, many large corporations are implementing home office-worker programs and are purchasing systems for their employees to take home. Removable hard drives are ideal for these applications because workers can take their drive with them when they visit the work office and quickly load all of their files onto any PC in the building. E-mail, e-fax, teleconferencing, wireless communications, mobile computers coupled with removable and transportable large capacity magnetic storage devices, reports, designs, software programs, video editing, graphic designs, etc. can be generated at home during flexible hours and later delivered to the work office quickly and efficiently. Initial reports indicate significant advantages in productivity and cost savings of such telecommuting programs.

Another perfect application is the sharing of workspace and a PC between two or more employees, which some companies are moving towards due to physical space limitations or cost reduction mandates. With a portable hard drive, large data files, application software, and operating systems are all safely transportable instantaneously to other computer systems without agonizing download time, other hardware implications, or fear of damage.

If a removable hard drive is selected to be the "C" drive, it can be bootable, and consequently used for dual operating systems. This feature is attractive to bilingual operators who run two or more language versions of Windows interchangeably or users that need to boot up different operating systems on the same PC.

Numerous industries and applications benefit from removable hard disk drive architecture such as video editing, graphic artists, CAD/CAM, game developers, software developers, government agencies, banking, insurance, legal, or medical imaging.

In the past when a disk drive was updated in a personal computer, the old disk drive was thrown away. Statistics indicate that millions of disk drives were discarded, wasting billions of dollars. This wasteful activity can now be reversed with removable drives because when the disk drive becomes full, it can be archived without fear becoming obsolete in the future. Thus, one can start building digital libraries for work purposes or for personal with home videos, photo albums, financial history, business correspondence, design activities, and any other digital data destined for future reference.

The convergence technology revolution is a new territory for exciting applications. Removable, rugged disk drives will be used as Internet and multimedia devices. Songs, video, animation, games, university courses will be downloaded from the Internet to a high capacity storage device like DataBook and then transferred to televisions, stereos, gaming machines, or automobiles.

In summary:- removable hard disk drive architecture offers efficiency, speed, economy, security, and convenience for multi-system users, telecommuters, and the convergence technology industry.

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