Magtape write rings [Was: Re: Full immersion emulation]

Mark J. Blair nf6x at
Sun Mar 5 12:41:59 CST 2017

> On Mar 5, 2017, at 09:49, Chuck Guzis via cctalk <cctalk at> wrote:
> I don't recall many who used those yellow rings for their intended
> purpose.  It was just too easy to forget to remove one.  You mounted
> tapes without and reached around the back of the reel with a punch card
> and tripped the "finger" that detected the ring.

So, was the write enable state latched at some point in the loading cycle on those drives? That surprises me, because I would have expected the write enable sensor to interrupt write current as combinatorial function on the drive, and/or pass sensor status up to the formatter a combinatorial signal.

Mark J. Blair, NF6X <nf6x at>

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