*** Ideas needed for developing interactive displays....

From: ed sharpe <esharpe_at_uswest.net>
Date: Sat Sep 11 23:03:22 2004

I like the core one!
sounds great Stan!

ed!
----- Original Message -----
From: "Stan Sieler" <sieler_at_allegro.com>
To: "ed sharpe" <esharpe_at_uswest.net>; "General Discussion: On-Topic and
Off-Topic Posts" <cctalk_at_classiccmp.org>
Sent: Thursday, September 09, 2004 7:17 PM
Subject: Re: *** Ideas needed for developing interactive displays....


> Re:
>
>> Most of our displays here at the museum are pretty static.....
>>
>> we are looking for ideas on introducing some interactive component...
>> ideas
>> folks?
>
> I just got back from Boston (www.noreascon.org), where I happened
> to visit the Museum of Science. On the second floor, they've got
> a history of computers display with a couple of interesting
> interactive displays.
>
>
> 1. core memory
>
> They had a large size plane of core memory (about 1 foot by 1 foot)
> holding a total of 6 (yes: SIX!) bits of memory. The display allowed
> the visitor to press one of two buttons to select a row, and one of
> three buttons to select a column. By pressing one of each (at the
> same time) you stored a bit into that core (can't recall if you could
> choose between 1 and 0). (And, there was an "erase" button, which may
> have erased all 6 bits.) To see how the core was set, there were 6
> small compasses...one by each core. The cores were *large*, about
> 1.5 to 2 inches in diameter. If you changed the setting of a bit, you
> saw that bit's compass needle swing aroung 180 degrees (real compasses,
> BTW).
> In short, a great visual aid to understanding how core memory works.
>
>
> 2. disk drives
>
> They had a model of a disk drive, with one spinning platter (18" in
> diameter?) and a head mechanism (the mechanism didn't move, sigh).
> The platter had two tracks of data, with about 8 bits per track,
> giving the "drive" a grand total of 2 BYTES of storage.
>
> The visitor could press one
> button to select a track, and could then press "1" or "0" (IIRC) to
> record that value onto the bit ... as it passed under the disk head.
> How could you tell when the bit was passing under the head? Each bit
> was a magnetized donut, with one half painted red, mounted in a hole
> in the platter (about a 2" hole) suspended on an "axle" that was
> parallel to the platter (and capable of rotating).
> I assume there was some kind of small magnet, or adequate friction,
> to prevent the donut from rotating at random. The disk head was an
> electromagnet, which would cause the
> red half of the donut to either be attracted (leaving the red half
> "face up" (let's call that a 1) or repelled (leaving the red half
> "face down" (a 0).
>
> The head mech contained a sensor to read the value of the bits as
> they passed under the head, and there were a pair of LED displays to
> show the status of the 8 bits (so the disk was probably hard sectored :)
> (yeah, such a displau isn't realistic, but it was nice to have.)
>
> Both displays were fun to use!
> --
> Stan Sieler
> sieler_at_allegro.com
> www.allegro.com/sieler/wanted/index.html
>
>
Received on Sat Sep 11 2004 - 23:03:22 BST