Mystery Core

Rick Bensene rickb at
Thu Apr 30 14:11:36 CDT 2009

Mike L. wrote:
>     Can anyone identify these boards?
>     They're stamped IBM, with etched numbers LBJ5360, LBJ5403 and
> LKJ12470.
> The owner says they were given to him in 1978, and were supposedly
> North Bay, Ontario.

I can't identify the application, but these probably aren't read/write
magnetic core memory.
Based on the way they are wired, they look more like ROS (Read Only
Storage, IBM's TLA for ROM).
Each board looks to be a 10 word by 10-bit ROM.
Can't say this definitively, but it's a semi-educated guess.

Rick Bensene
The Old Calculator Museum

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