Who wants to help read a Saturn V core stack?
dkelvey at hotmail.com
Tue Nov 11 00:37:16 CST 2008
> From: ard at p850ug1.demon.co.uk
>> Those of you with experience reading cores, we need your help in
>> reading out a LVDC core stack.
> Ouch!. I don't have much experience of reading core, but I've worked on
> core memory systems (I guess many others here have too).
> Rememebr that reading core is destructive. Basically, the read operation
> is to write a 0 to each core and see if there was a change in magnetic
> flux in that core. If there was, it _was_ a 1. If not, it was (and still
> is) a 0. Normally you then write the 1 back if appropriate.
Reading shouldn't be too difficult. Outputs could be recorded by
a digital scope. The rise times of the address and inhibit lines
are mostly to be slow enough that it doesn't cause the sense
amplifier to trip on the coupling in the selected address line.
Other addresses are protected by the matching signal on the inhibit
line. Any reasonably slow ramp would work since one is using a
scope to record and not a sense amp.
The levels needed can be determined experimentally since the amplitude
of the read signal is indepedent of the address signal size ( assumming
that there is sufficient signal to cause the core to switch ).
There is little leakage of flux outside of the cores. Any method
to read an exterenal flux would be difficult to detect. I doubt
a hall efect would be sensitive enough. Maybe a SQUID could be used.
There are ones that are used to detect small shorts inside of
Still, I think the easiest method is as I described, using an electrical
method and tries using small increments in the current.
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