History (1991): Soon Double Capacity for IBM 3480 Tape Cartridges

In a few months, or even a few weeks from now, IBM should announce a new 3480/3490 type magnetic tape cartridge with a double storage capacity, growing from 200 to 400MB.

We questioned someone in charge at the company who rather not have his name mentioned, and he answered: “I can’t say yes, but I can’t say no either, but it’s not far.”

The doubling of the capacity would be the result of changing the longitudinal recording from 18 to probably 36 tracks. A compatibility, at least in the read mode, should be guaranteed between the old and new cartridges.

And by using IDRC data compression method, proper to IBM, it multiplies recorded data by 3, the cartridges would be equivalent to an average 1.2GB capacity.

This is probably just a step since other improvements should follow as IBM will increase longitudinal density and the length of the tape in the cartridge, without loosing any of its performances, especially when you transfer data. Only if the tape is lengthened the average access time will be longer.

These coming announcements prove that longitudinal recording tapes haven’t said their last word vs. 4 and 8mm helical scan recording tapes (DATs) with capacities ranging from a little more than 1GB and close to 5, but with transfer rates far from IBM’s 4MB/s.

Big Blue also hopes this improvement in its 3480/3490 cartridges will be an extra argument vs. automatic robot manufacturers that the firm doesn’t have in its catalog. In this story, the target is mainly StorageTek. The new tapes will need less handling. But it seems doubtful that a simple capacity doubling could be enough to stop StorageTek’s undeniable success.

This article is an abstract of news published on the former paper version of Computer Data Storage Newsletter on issue ≠37, published on February 1991.