Fujitsu DynaMo 1300SF Review

Author : Wayne : 29th August 2001

3DVelocity would like to thank Fujitsu and especially Mike Bain for their help and courtesy in providing this unit for review.

Introduction :

If there's one thing the PC doesn't lack it's data storage options. From Zip to LS120 disks, solid state USB storage, CD-RW, Tape and of course the humble hard disk, it would appear that the data storage field is pretty much covered, so why bother with the relatively expensive option of using magneto-optical storage? Well, despite its cost, magneto-optical storage does offer advantages you'll not find on any of these other drives, but whether or not that justifies the price premium is something I want to look at today.

The 1300SF was until recently Fujitsu's largest capacity magneto-optical drive (MO as we'll call it from here on) to date boasting an impressive 1.3GB of storage space. It is also backward compatible with ISO compliant 3.5" capacities of 640MB, 540MB, 230MB and 128MB.

Benefits :

To understand the benefits of MO drives we need to understand a little bit about how they work. Unlike conventional magnetic or optical media, a MO drive uses a combination of magnetic and laser technology to write to a disk. Conventional magnetic drives are not able to produce magnetic field that is focused tightly enough to pack in the levels of data required by modern demands, plus it is also very sensitive to the effects of external magnetic fields that have to potential to corrupt the data that has been written. In addition to this, conventional optical media such as CD-RW is known to deteriorate over time and was too unreliable at the write stage to be considered a sound option for many companies looking to archive massive amounts of data. The way to overcome both these problems is with MO technology.

In a nutshell, a magneto-optical disk consists of four layers, though as with photographic film individual manufacturers often add additional layers in an attempt to improve performance and reliability, but for now let's concentrate on the four key layers. Front and back are the conventional plastic protective layers, but sandwiched between these are an alloy and an Aluminium layer. The purpose of the Aluminium layer is simply to act as a mirror, reflecting the light from the laser back towards a light sensitive pickup, while the alloy layer that sits on top of this is a crystalline substance that's little more than a few atoms thick. This crystalline layer has the ability to polarise light provided its crystals are magnetically aligned, but in order to align these crystals it must first be heated to a critical point known as its "Curie Point" (around 180 to 200 Celsius). Because only the crystals that have been heated to this critical point can be aligned by the MO drive's magnetic head, the density of the data on the disk is a function of the laser's ability and not the magnetic head's. Once cooled again, the crystals become locked in their new alignment and are impervious to external or internal magnetic fields until heated again.
The reading of the disks is performed by a much lower powered laser that picks up the state of polarisation without reheating the alloy.

In order to be able to read and write earlier, lower capacity disks, Fujitsu developed a technology known as MSR (Magnetically Induced Super Resolution) which incorporates IRISTER, or Iris Thermal Eclipse Reading. This works much the same way as the aperture control in a camera, narrowing the laser spot for 1.3GB disks while opening up and using a larger spot for lower capacity disks.

So the key advantage to MO disks is stability. These disks are resistant to things such as shock, vibration, moisture, dust, and magnetic fields and as such are used world-wide for archiving critical data. In fact such is the reliability of MO technology, you'll find it in use with the FBI for storing fingerprint files, with hospitals for patient records and even with NASA for mission details. Factor in the fact that you can write to a MO disk around 100,000,000 (one hundred million) times, and that they have a shelf life believed to be between 50 and 100 years and you have a rock solid data storage solution that you know you can rely on.

Before we take a closer look, let's check out the specs.

Specifications :

	DynaMO 1300SF Capacities
Disk format	ISO 10090	ISO 13963	ISO 15041		GIGAMO
Storage capacity	128MB	230MB	538MB	643MB	1283MB
Sector size	512 byte	512 byte	512 byte	2,048 byte	2,048 byte

 

		DynaMO 1300SF Specs
Model number		MDG3130SS
Disk format		ISO 10090	ISO 13963	ISO 15041	GIGAMO
Random seek time		23 ms
Average latency time		6.6 ms			9.3 ms
Rotational speed		4,500 RPM			3,214 RPM
Recording density (BPI)		24,400	29,300	52,900	89,100
Track density (TPI)		15,875	18,275	23,090	28,200
Data transfer rate	Drive	1.37 MB/s	1.65-2.65 MB/s	2.98-4.96 MB/s	3.46-5.92 MB/s
	SCSI-2 Interface	5 MB/s (async) 20 MB/s (sync)
Recording code		2-7 RLL		1-7 RLL
Interface		Ultra SCSI
Average load time		8 sec.			12 sec.
Average unload time		4 sec.
Buffer size		2 MB
MTBF		120,000 hours
Component life		5 years
Warranty		1 year

 

		DynaMO 1300SF Physical Specs
Power requirement		100 - 240 VAC
Power consumption	Operating	15.0 W
	Sleep mode	6.5 W
Dimension (H x W x D)		33.5 x 122 x 224 mm
Weight		1.0 kg
Ambient temperature	Operating	5ºC - 45ºC
	Non-Operating	0ºC - 50ºC
Relative humidity		10 - 85% (non-condensing)
Vibration	Operating	0.4 G (5 - 500Hz)
	Non-Operating	1.0 G (5 - 500Hz)
Shock	Operating	2.0 G (5 ms)
	Non-Operating	50 G (5 ms)
Altitude	Operating	3,000 m
	Non-Operating	12,000 m

The Drive :

Styling of the 1300SF is probably best described as "retro". Its ribbed Aluminium look outer casing reminds me of those American diners you so often see, while its smoked translucent sides and combination of slab-like lines and unexciting curves make it something you'll either love or hate. For the record I fall into the latter category but I'm sure there are plenty who'll find its styling exciting and refreshing. The front panel consists of nothing more than the loading slot, a power status LED, and eject button and a hole for the emergency eject function as found on almost all CD-ROM drives. On the bottom you'll find nothing more than the label, four minimalist rubber feet and a recessed power socket. The drive is also surprisingly heavy too tipping the scales at 1Kg

.

Loading the disk works in the same way as loading a floppy disk, though you have to push quite hard before it "clunks" in to place, not exactly an illusion of elegance to this side of things. Fortunately it's a powered eject which reminds you that you're not using a 30 year old peripheral.

A look at the back of the drive reminds us that you have the useful ability to connect using either USB which offers a meagre 1.2MB/S, or Ultra SCSI which offers a theoretical maximum of 20MB/S, either way the drive tops out at 5.92 MB/s so though this is beyond the scope of the poor old USB port, it's well within the Ultra SCSI ceiling. On the back of the drive are the power button, a bank of DIP switches and a SCSI ID selector in addition to the two SCSI connectors.

 

Fujitsu recommend the DIP switches remain at their default settings, but should you desire you are able to alter various settings such as Write Cache and Auto Spindle Stop.

 

 

The disks themselves are 90mm (3.5"), 1.3GB magneto optical and are a break from the conventional 5.25" platters that have been fairly universal up until now. As with the humble floppy, they are encased in plastic to prevent dust etc. Prices for new disks seemed to vary quite a bit, but the average was around $100 (£72) for a pack of five which I consider quite reasonable.

 

As you'd expect, there's an activity LED on the SCSI connector so you know when the drive's busy, but considering it may well be tucked under or on a shelf or monitor, I'd have sooner seen a front facing LED used too.

Page2 Testing and Conclusion