idea for a universal disk interface

[John Foust]

At 08:45 PM 4/13/2022, Fred Cisin via cctalk wrote:
>It certainly seems that it would be THEORETICALLY POSSIBLE, with an extreme budget, to build a high resolution device similar to the 3M Magnetic Tape viewer, . . . https://blog.adafruit.com/2020/03/01/the-magnetic-tape-viewer-see-the-sound-on-a-tape/

And how often do those antique viewers come up on eBay and at what price?

Modern ones are for sale for about $120:

https://store.arnoldmagnetics.com/product/284/magnetic-viewer-b-1022

But you can't really use an optical method, right?  You need to scan
the field another way.

And if you set a limit on disk platter tech to anything made before 1985,
what's the magnetic resolution you'd need and what would you need to detect?

Could the reconstruction be software-based, reconstructing from data
gathered while scanning X-Y across surfaces using a mechanism not 
unlike a scanner or 3D printer?  Or would you need to scan like
the flying head that wrote the data back then?

>So, I am making a 24" patio table out of it (under 3/8" tempered glass).
>http://www.ed-thelen.org/RAMAC/RAMAC_Plaque_v40.pdf

A rare item.  How many others have you seen in the wild?

- John