TECHNICAL HIGHLIGHTS

AVATAR SYSTEMS CORPORATION'S
AR-2170NI AND AR-3170FS


TECHNICAL OVERVIEW

Avatar Systems Corporation has announced a family of rugged, high performance 2.5 inch removable cartridge disk drives. The family includes the AR-2170, and the AR-3170. These products were designed to provide optimized data storage for the next generation of 486 + Pentium based notebooks, desktop and workstation computers.

The AR-2170 is a 2.5 inch removable cartridge drive with a sub 12 millisecond average access time, 20 Megabit per second transfer rate, adaptive embedded sectored servo, thin film Read/write heads, a 16 bit microprocessor, ramp loaded heads, and a high performance rotary voice coil actuator. These advanced features ensure superior performance and data handling reliability. The product is available with either a SCSI-2 or IDE/AT system interface. The proprietary HARDiskette (HD) contains a rigid glass recording disk which spins at 3600 revolutions per minute and provides 170 Megabytes of usable formatted storage.

The Magnum AR-3170 is a multifunctional storage device which includes an 170 Megabyte 2.5 inch HARDiskette drive and a conventional 1.44 Megabyte 3.5 inch floppy disk drive uniquely package in the industry standard 1 inch high, 3.5 inch form factor.

The AR-3170 is available with either SCSI-2 or IDE/AT system interfaces for the HD drive and a complete, independent FDD interface for the floppy disk drive which requires no host system hardware or software changes.

Avatar's disk drives are reliable, designed specifically to meet stringent operating environments and utilize much less power than typical 2.5 inch fixed disk drives. Lower power consumption is achieved by retracting the Read/write heads from the recording media when the drive is in a power saving mode. Since the heads never come in contact with the media, spin-up times and power are reduced.

Avatar Systems' removable cartridge proprietary technology enables its HARDiskette drives to absorb up to 200 plus Gs in the non-operating mode. The HARDiskettes are designed to survive major catastrophic shock, equal to dropping them from 48 inches to a hard surface.

DISK DRIVE FORM FACTORS

The AR-2170 has an industry standard 2.5 inch profile and is only 3.5 inch standard of only 1 inch high. These form factors allow computer system manufacturers to use industry standard configurations throughout their product lines with minimum design changes. While the HD-170 was primarily designed for mobile computing applications.

RUGGED DESIGN

Avatar's removable cartridge disk drives have to be capable of surviving a high degree of shock and vibration due to the unpredictable and sometimes adverse conditions under which they operate. The AR-2170NI, and AR-3170FS designed to accommodate harsh environments.

Conventional fixed disk drives allow the Read/write heads to drag along the disk surface until the disk has stopped. Since the heads are not flying they come in contact with the disk surface, eventually generating friction induced wear debris and damage to the critical head/disk interface. This continuous take off and landing process is believed to be a significant factor in stiction. Starting the disk repeatedly with the heads in contact with the disk may cause long term performance problems.

Avatar Systems' disk drives utilize a unique ramp loading mechanism for loading and unloading the heads without touching the recording media, which provides several benefits relating to ruggedness, reliability and low power consumption. The unique ramp loading and unloading mechanism eliminates the possibility of head slap in the power down state, providing the user unlimited disk starts and stops, and absolutely eliminates potential stiction problems. As a result, the spindle comes up to speed much faster and uses less power in the process.

Avatar's design team accomplished this by loading the disk heads onto an established air bearing after drive spinup. By using the stored energy in the drive's spindle motor, the heads are automatically retracted during all power down conditions. As a result of the built in ruggedness, the drives can withstand up to a 150 G shock in non-operating modes with the cartridge inserted, 200 G's without the cartridge, while protecting the cartridge only from catastrophic shock as high as 1500 G's. The hardy design makes the Avatar drive family ideally suited for potential shock intensive applications.

LOW POWER CONSUMPTION

In portable computer applications, conserving battery power is an important consideration. Avatar's unique ramp loading design offers the optimal solution to achieving the lowest levels of drive power consumption. The AR-2170NI and AR-3170FS average less than 2.2 watts in Read/write operation, allowing the use of smaller power supplies, fewer batteries and reducing overall weight and cost.

In conventional hard drives, known as contact start/stop drives, the Read/write heads land on the disk media surface whenever the drive is spun down. In addition to causing wear, eventual damage and potential data loss, contact start/stop drives require additional power during spin-up to overcome the frictional forces associated with the heads contacting the media.

Also, contact start/stop drives can only endure a limited number of power-on and off cycles. Since the heads of Avatar drives never touch the disk, the drives can be spun down as frequently as necessary to conserve power, such as during periods of inactivity. Also, the drives recover from sleep mode in approximately two seconds. Since the heads do not drag on the disk, spin-ups are faster and use less power.

PERFORMANCE AND BLUEPRINT RELIABILITY

Avatar's family of disk drives have made no comprises on performance or reliability. A low mass rotary voice coil actuator and a patented adaptive embedded servo provide fast seek times and unparalleled tracking accuracy. To ensure data integrity, there are built-in diagnostic routines and a powerful "on the fly" Reed Solomon error detection and correction code.

Data error rate reliability is specified at less than 1 error in 10 to the 12th bits. Meantime between failures is 100,000 hours, assuming 100% duty cycle. The Removable cartridge drive's component life is 5 years.

The AR-2170 disk drive families maintain less than 12 milliseconds average access time, track to track of 3 milliseconds, and less than 30 milliseconds full stroke. The average disk latency is 7.88 milliseconds, with a spin-up time of less than 3 seconds. Both the AR-2170NI and AR-3170FS drive provide 128 Kbytes of internal data buffering, have a track density of 3500 tracks per inch, and 1953 tracks per surface.

HD-170 HARDiskette

The HARDiskette is small, thin and offers a capacity of 170 Mbytes of formatted storage. The HD-170 is rigid, strong and shock resistant. The HARDiskette (HD) is designed to prevent contact with the data surfaces of the disk at all times. The disk is also protected by a locking shutter which automatically closes and secures the disk in place when the cartridge is not in use. During operation, an air filter provides a clean environment. Proper orientation of the cartridge with respect to the drive is Readily apparent and it cannot be inserted into a drive in an incorrect manner.

Each side of the disk is protected by walls made of dual stainless steel plates. Stainless steel provides high strength in a thin cartridge and protects the data from external magnetic fields. The dual wall construction makes the HARDiskette much more resistant to bending while also providing a channel for internal air flow and a guide to support the shutter. Cartridge air is pumped through a high efficiency air filter, resulting in rapid removal of particulate contamination.

The HD 170's cartridge shutter is locked closed when the cartridge is out of a drive, preventing access to the disk surfaces. When the HARDiskette is inserted into a drive, the shutter is automatically unlocked and opened. When the HD is not in use, the disk is held in place and is not free to move within the cartridge. This protects the data surfaces of the disk and also closes off the area around the hub of the disk to protect against contamination.

GLASS RECORDING DISKS

Portable and high performance workstation computers create a whole new set of demands for rigid disk media. In the demanding computer environments, disks have to maintain near contact flying heights, survive the hard impacts that come with portability, and continue to perform flawlessly at high areal densities. Glass has long been viewed as an ideal for magnetic media because it is harder, smoother, more stable and more resistant to surface damage than conventional aluminum substrates.

With today's portable and workstation computers, never has so much data been packed into so little space and had to take so much abuse. However with glass, data vulnerability to shock is much less of a problem. Pure, unblemished glass is actually stronger than steel, capable of withstanding hundreds of G's and sharp head slaps without damage.

Avatar chose a glass substrate magnetic media because of its clearly superior hardness, smoothness, and chemical stability. Now that increased storage densities demand the combination of ultra-low flying heights and ultra-high reliability, glass was the substrate of choice for our customer's tough, demanding applications.

Avatar Systems Corporation uses glass media exclusively in its removable cartridge disk drive products to ensure greater data reliability, ability to experience very high G forces, and to provide customers with the ruggedness they demand.

FLOPPY DISK COMPATIBLE

Avatar's multi-function AR-3170FS includes a reliable floppy mechanism that is fully compatible with today's conventional 1.44 Megabyte 3.5 inch floppy disk drives. The AR-3170FS provides a complete, independent floppy disk drive interface, and requires no host system hardware or software changes to operate the floppy.

Being able to Read and write standard 1.44 Megabyte and 3.5 inch diskettes as well as 170 Megabyte HARDiskette, provides the user with a bridge backward to their existing application software and databases and a bridge forward to the high performance 170 Megabyte HD technology of the future.

GLOSSARY OF SELECTED TERMS

AT Interface: IDE/AT, the connecting point to the IBM AT bus ( Integrated Device Electronics/Advanced Technology).

Built-in Diagnostics: Predetermined test algorithms stored in Read only memory (ROM).

BUS: An assembly of conductors for collecting electrical currents and distributing them to outgoing feeders in a bi-directional manner.

Closed loop: Continuously controlled system.

FDD: Floppy disk drive.

Formatted: The structure of the magnetic recording area either physically or electrically, into uniform addressed segments where data may be recorded, stored and retrieved.

Kbytes: Kilobyte - 1024 bytes.

Mbytes: Million Bytes - 1,000,000 bytes.

SCSI: Small Computer System Interface.

Servo: A self-correcting closed loop system used to make the head follow a predetermined path.