Another question about core sense amplifiers

[Rick Bensene]

OK, while we're on the topic of core memory sense circuitry, in some of
the old calculators that I've come across (a good example being the
Casio AL-1000 -- http://oldcalculatormuseum.com/al1kck10l.html) ) there
are transformers (pulse transformers) in the core memory sense
circuitry.  What purpose would these serve, and why are they used in
some core memory applications, and not in others? In the case of the
AL-1000, similar transformers are used in the X-Y drivers as well.

Core memory sense amps and drivers are that mystical analog stuff that I
don't understand very well :-)
Can someone enlighten me about these transformers?

Thanks,

-Rick
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Rick Bensene
The Old Calculator Museum
http://oldcalculatormuseum.com