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Bubble Memory:
What is it? Bubble memory stores data as a pattern of magnetization on the surface of a crystal, akin to a magnetic hard drive. The unique aspect is that it uses no moving parts; the storage medium remains stationary, while the data moves along its surface.
Historical Context: In the 1970s and 80s, bubble memory was promising due to impressive densities. However, it was eventually replaced by cheaper and more reliable flash memories.
The Project:
Controller for Bubble Memory Modules: The project involves creating a controller for Bubble Memory modules manufactured by Texas Instruments (TI) in the 1980s. Specifically, the project uses TIB S0004 memory modules. The controller is reasonably functional, capable of reading, erasing, and writing data. Some analog circuitry might need refinement.
Implementation Challenges:
Bubble memory modules lack an internal controller, necessitating external circuitry.
The controller generates carefully timed constant-current pulses to operate the modules and amplifies/processes the output from the bubble detector. Historically, control pulses were generated using logic circuits or micro sequencers. Documentation from TI and Intel assists with understanding the timing and control aspects.
The project’s success relies on a discrete-transistor implementation of the function pulse generator based on early design documents1.
It’s incredible how the breadboard version even worked well enough for bring up! The sense amplifier on a separate PCB adds to the project’s complexity. Bubble memory, though largely forgotten, remains a fascinating piece of computer history1.
