From: rdawson16 at
hotmail.com
Date: Mon, 26 Nov 2007 13:15:02 -0500> From:
ray at arachelian.com> To:> Subject: Re: *updating* 8088's>> Roy J.
Tellason wrote:>> On Friday 23 November 2007 19:05, dwight elvey
wrote:>>>>>> From: rtellason at
verizon.net>>>>>>>> I notice that even those guys that are
building relay computers "cheat">>>> and use a single small
solid-state chip for RAM. :-)>>>>>>> Hi>>> I've been
thinking about how one could make a reasonable>>> memory, using small reed
relays. If one puts a magnet close>>> to one end, it will cause the reed to
close. Move it back>>> some and it will hold until the field is too
weak.>>>> ..>>>> Dunno if they still sell them or not, but Radio
Shack used to sell a pack of>> 20 reed switches for only a couple of
bucks...>>>>>> Hmm... Wonder if it's possible to build a relay
without a spring on the> switch. That is, you have to send current with one polarity to
set the> switch to a 1 and reverse polarity to set a zero - sort of what core>
memory does with rings... I suppose this could instead be done by> attaching a magnet
to the switch, or using magnet as the thing inside> the switch body, or better yet
maybe a relay with a ball with a set of> contacts as the switch and two magnets, one on
each opposite side...> you'd energize one coil for a "1" and the other
for a "0">> Hmm, could even be done with a solenoid and use the mechanical
part of> it to touch a wire for output. :-) Wouldn't really be a relay, but>
pretty close.>>
Teledyne makes a 'non volitale' relay. its tradename is Maglatch.
Hi Randy
I used to use these or similar in equipment while I was in the service.
They were not real reliable and expensive. They were in a state machine
control for a reel to real multi track tape.
Every now and then we'd take the control board out and smack it
several times onto the work bench. It would work fine for a few
weeks and then need another smack.
I assumed that it was related to the armatures needing to be demagnetize
every now and then. They used a bias magnet similar to what I've
been suggesting to work with reed relays.
One thing I learned about reed relays is to not use a weller iron with
the magnetic heater switch. The reed relay would not open. I'd use
that method if it was more controllable.
Dwight
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