[Coco] LSN0 C code

[Steven Hirsch]

On Sat, 11 Jun 2011, gene heskett wrote:

> We had, past tense, a bulk eraser at the tv station that was apparently
> made for erasing the 10.5" and 14" NAB reels of audio tape.  But it fell
> into disuse when the 3/4" u-matic format for video came along as it was not
> strong enough to wipe all the way to the center.
>
> Somewhere in my collection I have one of the hand held ones that the Shack
> sold for cassette tapes, and it worked well on floppies, including 3.5".
>
> For audio work, it is very important that the media be removed very slowly
> from the field these generate before the power switch is released.  Turn it
> off while the tape is still in contact, and you likely will leave the tape
> very hissy & noisy, with a distinct, it will peg the vu meters thump once
> per turn of the reel.

As effective as those gadgets are on audio and video tape, they do not 
typically generate enough field strength to wipe linear digital media. 
It was eye-opening to run a DLT IV cartridge over my trusty, 40-year-old 
Nortronics desktop eraser and discover that it remained readable!

A link off that UTube page leads to an industrial-strength unit that is 
designed for DLTs.  I'm not asking, because I'm sure I cannot afford it 
:-).

FYI: DLT drives write their own servo information as they go and are 
designed to work with blank media.  The newer (and physically similar) LTO 
format has a factory-written servo track and will be destroyed completely 
by a capable eraser.  I'm sure a number of users have discovered this the 
hard way when they ruin a $40.00 cartridge.

Steve


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