On Fri, Feb 23, 2018 at 10:23 AM, Jon Elson via cctalk <
cctalk at classiccmp.org> wrote:
The original bubble memories were sort of dead end,
but applying more
advanced semiconductor lithography to them, going to vertical Bloch-line
memory architecture, and such could have given them a lot more life, at
least. But, when IBM pulled out of the advanced research on it,
development just stalled
I don't know what "vertical Block line memory architecture" is, but more
advanced lithography wasn't sufficient, because the size of useful magnetic
domains couldn't be scaled down much smaller than what was used in the
4Mbit devices, no matter how fine your lithography was. The lithography was
not the limiting factor. That's why Intel spun off their magnetics division
to continue manufacture and sales of what they recognized as a dead-end
product line. It was still viable for some years as a niche product in
applications where the requirement for physical robustness was far more
important than either density or price.