Help reading a 9 track tape

Chuck Guzis cclist at
Fri Aug 6 13:37:02 CDT 2021

On 8/6/21 10:27 AM, Paul Koning via cctalk wrote:

> That was done by a number of people using MR (magneto-resistive) heads.  John Bordynuik was one of them, years ago; some others have done likewise.  Those heads were built by IBM for high density tape cartridges; 6250 is low density for them.  They have some nice properties, from what I understand, one of them is that the output signal levels don't depend on the tape speed as regular inductive heads do.  So for old tape recovery you can readily run at very low speeds if needed to protect fragile media.

IBM 3490 - 36 track.  The 3590 and later get silly numbers of tracks on
half-inch tapes.   Don't know if the 18-track 3480 was MR, however.

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