I don't know specifically what this one is, but I can say that
magnetostrictive
delay line technology was very common in early electronic calculators.
These devices
used magnetostrictive 'tapes', which would change length when a magnetic
field is applied.
These tapes served as transducers which were connected to the ends of
a long coil of special wire, into which acoustic pulses were launched.
The pulses
would travel to the other end of the coil of wire, and be picked up by a
similar transducer at the other end.
Most calculators would need to store between 128 and 2048 bits, and ran
at clock rates between 30KHz to 500KHz. Many interesting schemes were
used to initialize the memory, as well as synchronizing and re-timing
data as it circulated through the delay line.
The delay lines were relatively temperature stable, but were susceptible
to mechanical shock.
I've had a number of cases where you could really confuse a calculator
by simply sharply tapping
the case of the delay line.
This technology was actually used into the early 1970's, as it was
inexpensive compared to
other technologies such as discrete transistor flip flops, magnetic core
memory, small-scale IC flip flops, and small magnetic drum memory.
Even by the early '70's, when MOS IC technology started to become
mainstream, the delay lines were
still more cost effective than MOS shift registers. But, by '72 and '73,
when Large Scale Integration (LSI) devices became mainstream, the era of
the magnetostrictive delay line came to an end.
There are lots of examples of calculators with magnetostrictive memory
(Friden was a frequent user of the technology) on my "Old Calculator Web
Museum" website at
http://oldcalculatormuseum.com
Rick Bensene
The Old Calculator Web Museum
Sellam wrote:
> I was scrounging around in a surplus electronics shop the
> other day and came across an interesting part. It was a
> Delay Line, part number ADL-CN037. I forgot who the
> manufacturer was, but it was someone big and established (GE maybe)?
>
> Anyone know what this is?
>
Received on Sat Jun 12 2004 - 22:06:20 BST