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AIT (Advanced Intelligent Tape) Technology


AIT Drive and Media

Up until 1996 the 8mm tape market was the exclusive domain of Exabyte Corporation, and Sony were primarily operating in the 4mm market with DDS DAT (They did also offer DTF, a high performance tape system used largely by the film industry).

In 1996 Sony targeted the higher end of the storage market with the 25GB native capacity AIT drive. The AIT used the same physical media as the Exabyte Mammoth, but with the addition of MIC (Memory in Cassette).

Since 1996 AIT development has taken a number of paths. The conventional one whereby every few years a new drive is launched with double the capacity of the previous one has led to the existence now of AIT-5 with a native capacity of 400GB and AIT-6 planned, with a native capacity of 800GB. At the same time Sony have picked at the 4mm DAT market by offering lower cost drives based on the older formats that offer a logical evolution from DDS4 and DAT72.

The other major AIT development has been SAIT, or Super AIT. This is targeted more towards the specialist market where DTF was a popular choice.

How AIT Works

AIT uses helical scan recording method similar to DDS DAT (as opposed to the serpentine or linear method of recording employed by DLT and LTO technology). The recording media is 8mm wide and uses AME (Advanced Metal Evaporated) material for it's recording surface. AME allows for a high-density, high durability recording.

helical scan recording

Above: Helical scan recording

With helical scan recording, data is written to a relatively slow moving tape via a fast spinning read/write head drum. This technology has the reported benefit of greater head durability, and reduced shoe-shining effect, the to and fro-ing tape motion that can occur in linear recoding if data is not slower than the recoding speed.

AIT (apart from AIT-E) uses MIC (Memory-In-Cassette) to store information about the physical recording on the tape. This allows for quick loading and faster seek times.

AIT tape external dimensions are 95mm x 62.5mm x 15mm (W x L x D) and uses a cassette type format, where the source and take-up spool are within the cassette rather than a take-up spool within the drive.

Data Recovery From AIT

AIT does not, in our experience, have any peculiar faults that result in the requirement for data to be recovered. The cassette casing is similar to 4mm DAT in that it uses a spring loaded shutter and this if the the unload mechanism does not operate correctly can lead to tape damage.

Other instance of drive malfunction can cause the tape to become wrapped around the fast spinning drive head effectively un-spooling the tape onto the read-write head assembly. In such instances it important to remove power from the drive and not to try and remove the AIT cassette or the tape from the drive if you require the data to be recovered. The whole drive should be shipped to us where our tape data recovery engineers can fully assess the damage and free the tape using the correct procedures.

Over many years the most typical tape problems our engineers have encountered with AIT media are media failure caused by overuse, overwriting of data and problems with corrupted backup. We have found AIT to be reasonably data recovery "friendly", the media is strong and durable and because of the helical scan operation if physical damage does occur it affects only a small area of the recorded data leaving the remainder accessible for data recovery.

AIT Tape Capacities

GenerationNative CapacityData Rate (MB/s)YearTape LengthWORMEncryption
AIT-E 20GB 6 2004 No No
AIT-1 25/35GB 3/4 1996 170m/230m No No
AIT-1 Turbo 35GB 6 2004 230m No No
AIT-2 50GB 6 1999 230m Yes No
AIT-2 Turbo 80GB 12 2006 230m Yes No
AIT-3 100GB 12 2001 230m Yes No
AIT-3 Ex 150GB 18 2006 230m Yes No
AIT-4 200GB 24 2005 246m Yes No
AIT-5 400GB 24 2006 246m Yes No

Last Updated (Wednesday, 14 October 2015 15:56)

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