brad@kontron.UUCP (Brad Yearwood) (03/24/88)
Somebody who just returned from the CeBIT trade show at Hannover
dropped a tiny tape cartridge on my desk and asked how much it stored.
As the cartridge has about the length and width of a credit card and
the thickness of a slice of diet bread, I took a wild guess and
said 60MB.
Was I ever wrong. If this tape holds anything, it holds 1.2GB.
It's from Gigatape, located near Munich. They want about $7K
equivalent for the drive, depending on interface. A cartridge
is about $28. (That's an awfully spindly looking little scrap
of tape to be holding 1.2GB!)
Speed claims are 192KBytes/second while streaming, with a full tape
transfer taking about 2 hours. A fast search is claimed to locate
a block in 20 seconds average.
Such a device is very tempting for overnight backup use. Of course,
if you lose or damage one of those little tiny tapes, you've lost
a flaming big pile of data. Just the thing for storing the complete
history of Unix-vs-VMS flame wars.
They claim an error rate of 1E-15 (bits, presumably), but I see
no claims asserted about failure rates over time, or allowed
read passes of a tape once written to maintain that failure rate.
Hmmmm... is that figure for detected or for undetected errors?
The price seems high today, but it is almost certain to
shrink as competition develops and as DAT enters widespread
consumer use.
So my question is, just how far and how long can one trust such a tape?
The tape cartridge and transport are supposedly standard DAT equipment,
with Gigatape's read/write, Reed-Solomon encoder/decoder, and other
control functions.
Brad Yearwood
Kontron Electronics {voder, pyramid}!kontron!brad
Mountain View, CAcabo@tub.UUCP (Carsten Bormann) (03/30/88)
In article <1833@kontron.UUCP> brad@kontron.UUCP (Brad Yearwood) writes:
() [...] If this tape holds anything, it holds 1.2GB.
() It's from Gigatape, located near Munich. They want about $7K
() equivalent for the drive, depending on interface. A cartridge
() is about $28. (That's an awfully spindly looking little scrap
() of tape to be holding 1.2GB!)
()
() Speed claims are 192KBytes/second [...]
() Such a device is very tempting for overnight backup use. [...]
Gigabyte tape drives are certainly the wave of the future.
Due to the large numbers of systems out there that have Gigabyte
disk drives and no comparable backup devices, there is a huge market.
Currently there seem to be three contenders in this market:
1) Exabyte (with a product based on 8mm cartridges holding 2.2 GB);
2) Gigatape (R/DAT cartridges, 1.2 GB)
3) several companies in an ANSI committee talking about R/DAT.
I'm ignoring VHS cassettes here; these tapes with their exposed
oxide coatings do not really qualify for data storage (opposing
opinions are welcome).
All three systems are based on cartridges that are available in
consumer-grade versions, manufacturers usually want to sell their
``certified'' versions of the tape.
The 8mm cartridge (better known as Video 8) has been on the market
since (I think) 1983. The mechanisms used in camera recorders are
used for analog recording; therefore considerable modification
by Exabyte was necessary to make 8mm a digital medium.
R/DAT will be on the market this year (or next year, maybe) and
has been designed for digital recording from the outset.
Unfortunately, no standard has been reached yet that describes
how to record computer data on them. Gigatape is rolling their
own ``standard'' here (just like Exabyte is doing in the 8mm
range). However, Gigatape will have to fight with the ANSI people
currently discussing R/DAT as soon as agreements have been reached.
Since the ANSI standard is not yet available, the only things we can
compare right now are the two products (which are/will be sold at
comparable prices). My personal assessment of just Exabyte and
Gigatape:
1) Data reliability
Exabyte uses read after write and re-records bad data in considerable
distance to the original recording position. They use lots of redundancy
in their error correction codes (one third is redundancy, if I recall
correctly). The 8mm tape has not been pushed to its limits yet,
Exabyte may have higher-density products in the future.
Gigatape also uses error correction, but their published materials
do not talk about read after write at all. If they are using
consumer grade R/DAT drives, r-a-w would not seem to be possible.
I have no idea about how far you can go with R/DAT cartridges with
respect to recording density and if 1.2 GB is pushing anything.
2) Cartridge availability
You can buy 8mm cartridges of good quality in any supermarket.
R/DAT cartridges will only become available in quantity when the
audio R/DAT market has resolved the copy protection issues (which
is scheduled to happen this year, but may never happen at all).
3) Systems integration
Exabyte's drive has the 5 1/4" form factor, which is an important
issue when it comes to integration into existing systems. It runs
from standard +5/+12 volt power supplies.
Exabyte has a working SCSI interface with 1/4 MB buffer storage.
I have seen it streaming at more than 200 KByte/s. The interface
boards are built in high quality, using surface mount technology for
many components.
Gigatape's drive looks like a stereo cassette deck, no integration
into existing boxes is possible (but they are promising a 5 1/4"
version by the end of this year).
Gigatape is promising to have ESDI, SCSI and Pertec (half inch tape
drive) interfaces. Looking at the interface boards they displayed in
Hannover did not thrill me too much (they didn't even have the
solder stopping silk screen on them yet).
4) Market positioning
Exabyte tries to deliver a high-end product for the PC network,
workstation, and minicomputer market. They are a 50+ person company
with considerable funding, located in the US of A. They have a
second source in Japan.
Exabyte's product is available and has proven to work in varying
operating conditions.
Gigatape is a small German startup company (not that I dislike
Germany, but I don't know of many successful peripheral products
that originated from here).
In Hannover, Gigatape promised to deliver in April (I hear that they
repeatedly promised to deliver next month).
Disclaimer: I sometimes do some consulting for a systems integrator in
Germany, and I recommended Exabyte to them when they asked me.
--
Carsten Bormann, <cabo@tub.UUCP> <cabo@db0tui6.BITNET> <cabo@tub.BITNET>
Communications and Operating Systems Research Group
Technical University of Berlin (West, of course...)
Path: ...!pyramid!tub!cabo from the world, ...!unido!tub!cabo from Europe only.