DECtape madness

[Paul Koning]

> On Jan 13, 2018, at 12:28 PM, Al Kossow via cctalk <cctalk at classiccmp.org> wrote:
> 
> 
> 
> On 1/13/18 9:04 AM, Jon Elson via cctalk wrote:
> 
>> I don't know what you are talking about with Mylar on both sides. They were conventional magnetic tape, a clear mylar
>> film with oxide applied to one side.
> 
> the actual spec is here:
> 
> http://bitsavers.org/pdf/dec/dectape/3M_DECtape_Spec_Nov66.pdf

And that spec is quite clear, "protective overlay".  This is the reason for the legendary robustness of DECtape media.  It was possible to wear it out, but only if you used it -- as done at Lawrence University for example -- as permanently mounted public file storage so it was read/written many times per hour for months on end.  When used as private removable storage it was pretty much invulnerable.  Stories of DECtapes being laundered by accident and still working fine afterwards have been around for a long time.

	paul