Bubble Memory - test-drb@ccmp.vtda.org

14 Jan 1998

At 11:21 AM 1/14/98 -0500, you wrote:

...
 A type of non-volatile memory composed of a thin layer
of material that can
be easily magnetized in only one direction. When a magnetic field is
applied to circular area of this substance that is not magnetized in the
same direction, the area is reduced to a smaller circle, or bubble.  
One of the differences with bubble memory is that it has to be accessed in
a serial / sequential manner -- on a 1 megabit bubble device you cycle thru
all the bits, then grab a certain set of bytes from the device according to
an index or FAT. Tho the devices are rather quick, they do not have the
speed of hard drives. I believe you could put 8 devices in parallel, and
that would increase your access 8x, tho.

...
  It was once widely believed that bubble memory  would
become one of the
leading memory technologies, but these promises have not been fulfilled.
Other non-volatile memory types, such as EEPROM, are both faster and less
expensive than bubble memory.  
The cost of manufacturing bubble memories did not drop in price much unlike
other  technologies of the day.

You are correct, tho. Bubble memories are completely non-volotile and
require no power to preserve their memory -- I have no clue as to the
bit-rot spec's, tho. (A decent magnet will squanch your data.)

I have an article in Rainbow magazine on how to build a 128K byte device as
a near-line non-volotile storage unit for the CoCo -- designed by that
great master Dennis Bathory Kitsz. (apologies to Dennis if I misspelled.)

HTH,
Roger "Merch" Merchberger
--
Roger Merchberger       | Why does Hershey's put nutritional
Programmer, NorthernWay | information on their candy bar wrappers
zmerch(a)northernway.net  | when there's no nutritional value within?