
Core Memory Shield for Arduino - mhb
https://www.tindie.com/products/kilpelaj/core-memory-shield-for-arduino/
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sllabres
I have searched for a bit more info about core memory recently and found "Core
Memory Explained (and Demonstrated)" (~25 minutes) quite interesting:

[https://www.youtube.com/watch?v=AwsInQLmjXc](https://www.youtube.com/watch?v=AwsInQLmjXc)

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Isamu
Anyone have details about about where you get these tiny ferrite cores? I just
assumed they were no longer available.

I have a card of core memory from maybe a DEC10, but the fine copper wires
woven through the cores are starting to break. Not sure what I should do to
preserve it.

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FullyFunctional
When I asked Jussi (in July, 2016) he pointed me to
[http://www.ebay.com/itm/1000x-VINTAGE-RAW-FERRITE-
CORES-5221...](http://www.ebay.com/itm/1000x-VINTAGE-RAW-FERRITE-
CORES-5221-3-2113-35-FOR-CORE-MEMORY-BOARD-/311037935957)

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Isamu
Ooh, awesome! Thank you!

It would be cool to weave some rope memory with this.

[https://en.m.wikipedia.org/wiki/Core_rope_memory](https://en.m.wikipedia.org/wiki/Core_rope_memory)

~~~
FullyFunctional
Yeah, rope memory is genius. Practical storage from such as simple structure.
There's a demo somewhere on Youtube of someone who made a 7-segment decoder
with rope. Pretty simple circuit compared to what you need to read-write core
memory.

If you like this kind of things, you might want to check out the amazing ROM
implementation of the HP 9100:
[https://www.hpmuseum.org/tech9100.htm](https://www.hpmuseum.org/tech9100.htm)

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tombert
This is only tangentially related, but as someone who is incredibly new to the
Systems programming world, what would people recommend for getting into
Arduino programming? How different is it from programming the GPIO on the
Raspberry Pi?

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inetknght
That's an excellent question; one to which I would also like to know (more)
about. So far I've thrown a bunch of money at it to just buy random pieces and
cobble them together in spare time and see what happens.

So I _have_ raspberry pis; I _have_ arduinos. I've done some simple
programming for both, to read from sensors. Water sensors and thermal sensors
and buttons and sound pins all on breadboards were fun.

I figured I was ready for the next step: soldering together a kit. So I
soldered together an ethernet kit for the arduino. That project fell flat: the
arduino powered up while the ethernet shield did not; the arduino reported
that it didn't even "find" the ethernet controller even though it was piggy-
backed onto it. Usually when you plug in the RJ45 jack to a NIC you at least
get the lights on the RJ45 port to light up. But no dice for me here either.
And I have no idea how to debug _that_ problem.

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jsjrobotics89
Sounds like you need to triage your circuit. Every trace should be connected
to a certain number of other points. Turn off power and use a multimeter on
the continuity setting to verify each trace connects to where it's supposed
to.

After that, turn on power and verify that each trace has the correct voltage
on it.

The two steps above should let you determine which part is failing.

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berbec
Next up, punch card reader for BeableBone

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FullyFunctional
Punch cards are mechanically demanding. A paper tape _reader_ is feasible. A
_writer_ is probably fairly challenging.

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mjcohen
Early in my programming career (probably late 60's), I came up with the
universal data storage media: punched magnetic tape!!!

