Re: imaging/duplicating HP tape cartridges - lots of questions


On Feb 20, 2017, at 10:50 AM, Paul Berger <phb.hfx@...> wrote:

You could talk directly to it by replacing the processor card or writing custom code for the processor in it  (BPC only version of the processor in 9825), but it would probably take some probing to discover how to talk to the TACO.

I wonder if the TACO chip is an enhanced version of the tape controller in the 9825.  The comments in the 9825 tape firmware listing led me to think some portion of the code might be shared with the 9875, in particular the portion known as the “Tape Driver” that resides in the ROM at 020000.  The 9825 FW keeps track of tachometer pulses to know how far  it has moved the tape, and does the data stream bit serialization/deserialization operations in FW.  It also manages the two levels of the read threshold to check if data will be likely to be read back correctly.

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