magnetic tape for data storage

once universal, now forgotten, storing digital data (not analog sound) on magnetic tape is pretty much a lost art. i like magtape for its physicality. a small reel of half-inch tape typically holds 10 megabytes, for an approximate sense of working with it. the specifics of linear magnetic data recording have very little presence on the world wide web for a number of reasons; while disk drives are certainly magnetic storage, the techniques and materials used have gone off into the stratosphere, science-wise, and are highly proprietary (and industry has become reluctant to share); magnetic cards have become a specialized niche. the practice of general purpose, low-density (200 to 1600 bits/inch) magnetic recording has (not unreasonably) disappeared; it was old when the web started and industry has no use for it today.

DIGITAL MAGNETIC TAPE RECORDING FUNDAMENTALS, Training Manual, sos 900554A. republished by SDS, this 1962 Ampex document remains a good summation of the state of the art through the 1970's.

Friden (Pertec, Singer) 4311 Magnetic Data Recorder manual. this is the donor of my Pertec 7870 7-inch, 800 bpi drive.

PCC models T6x40 et al synchronous tape transports. technical manual of a more sophisticated drive of the same era, the data read write circuitry is genetically similar and useful for decoding the Friden read write board.