40k Ferrite Memory Core

[Chuck Guzis]

On 29 Oct 2008 at 12:52, Rick Bensene wrote:

> I agree with Brent's analysis.  I too counted 21 planes, which seems a
> bit odd, as typically each plane represented one bit in a word
> structure, which would indicate a 21-bit word...not something that
> matches up with commonly-used word sizes in 50's/60's era computers (12,
> 16, 18, 20, 24, 32, 36, 48, 60 or 64 bits). 

An extra parity bit per word was very common(some Seymour Cray boxes 
excepted). My guess is this might be from a GE 200-series mainframe.

Can one still get ferrite cores with hard magnetization curves for 
logic any more?  I've always had this secret desire to play with 
magnetic core logic (not memory).

Cheers,
Chuck