Building RAM: An Electronics Project

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performaman's picture
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I've been bored lately, and I have decided to try to build a 1 byte RAM unit using capacitors. I plan to make a reader for 3x5 cards that would detect which of 8 "cells" on the card were blacked out and store that data in the RAM unit. Eventually, I plan to build a logic circut or program a microcontroller that would let the output from the cards be displayed on a LCD. I have the RAM unit planned out as well as the card reader (a light on the bottom and switches that only allow current to flow if there is no light- can't remember their name right now). The switches would turn each cell in the RAM unit "on". My only problem is that I don't know how to keep the switch in the RAM "on" even after the reader has been turned off. I need to scan some schematics and post a link to them, so any help would be appreciated.

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Tom Owad's picture
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Schematic

A schematic would definitely help. Is this your own design?

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performaman's picture
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Yes.

The schematic is something I made in MS Paint. I've drawn one, but my computer dosen't have a scanner. It dosen't use regular electronic schematic symbols for components.
Here's the schematic: http://rain.prohosting.com/pjman/RAM.jpg
The connector marked "indicator" would close to turn on a light, darken a section on an LCD, send information to a chip, microcontroller, etc.
The switch is a section that would be closed by the light sensors I mentioned earlier. The problem is how to keep it closed after the card reader is removed.
"Don't do drugs or you'll end up like the people that made HURD."
-Linus Torvalds

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Tom Owad's picture
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timed out

Your server isn't responding. Just upload the image to your personal image gallery.

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performaman's picture
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I've uploaded it...

..but I don't see it in my image gallery.
"Don't do drugs or you'll end up like the people that made HURD."
-Linus Torvalds

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jt
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Where's the 2.0 manual . . .

. . . anyway?

. . . I can't figure any of this crap out, gotta RTFM. =8-/

BTW, is there any way to code the forum sig routines so they appear a few lines down with the cursor at the home position in this freakin' window? This is annoying as all get out the way it works now.

. . . and the open links in the same window bug is STILL makin' . . .

jt

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Tom Owad's picture
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Image fixed

When you uploaded the image, you left personal gallery disabled.

Here it is: Schematic for RAM project

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jt
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google core memory . . .

. . . for something that simple, maybe could use coils to magnetize/demagnetize something big enough to look cool.

If you use those hand wound nail-n-wire motor/solenoid project thingies and a solenoid actuated release/catch mechanism cycles/switches in a vertical config, it'd be awesome to watch it stroke up and down like a straight 8 reciprocating engine. The metal parts would sit there wherever they were at powerdown until you powered up again.

If you follow the KISS principle, solenoid actuated teeter-totter switches would give you the same kind of nonvolitile logic state storage with more energy efficiency by using ACTUAL physical flip-flops . . .

. . . but you'd have to forgo the side order of kinetic energy demonstration . . .

. . . and the big block piston pumping action! Evil Block Company

jt

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edit: I think I boo-booed, I thought this post got eaten, but maybe it's a comment appended to the piccie? . . .
:? . . . another posting adventure on the new 'fritter 2.0!

*cues twilight zone theme* Wink

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Re: Where's the 2.0 manual . . .

jt wrote:

BTW, is there any way to code the forum sig routines so they appear a few lines down with the cursor at the home position in this freakin' window? This is annoying as all get out the way it works now.

. . . and the open links in the same window bug is STILL makin' . . .

TO ... you want me to work on those :? IM me!

also can we get the BBcode bar back :?

TOM

performaman's picture
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Re: google core memory . . .

jt wrote:

. . . for something that simple, maybe could use coils to magnetize/demagnetize something big enough to look cool.

If you use those hand wound nail-n-wire motor/solenoid project thingies and a solenoid actuated release/catch mechanism cycles/switches in a vertical config, it'd be awesome to watch it stroke up and down like a straight 8 reciprocating engine. The metal parts would sit there wherever they were at powerdown until you powered up again.

That sounds cool. I think I have a kid's science book from when I was younger that describes how to build a solenoid.

Quote:

If you follow the KISS principle, solenoid actuated teeter-totter switches would give you the same kind of nonvolitile logic state storage with more energy efficiency by using ACTUAL physical flip-flops . . .

I'll google those too.

I'm also thinking of taking the actual magnetic disk part of a floppy disk (got lots of corrupted 5 1/4 disks), cut it into pieces, place the pieces over an electromagnet that would turn on and magentize the disk. (kind of like Twister) I don't know how I would read from the magnetic material (cassette read heads?).
But the solenoids do sound like a good ideia. And they'd look cool.
Another option is using a saline mixture and solenoid operated valves that would allow the saline to connect two electrodes. Not very pratical, though.
Thanks for the ideias, JT.

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performaman's picture
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Tom won't like this, but...

...I've decided to use solenoid switches, with the switch assembly made from EBC bricks. The main reason is that I have a lot of EBC bricks, and that I can order specific bricks from the Lego in bulk.
The way the switch will work is that it will be a sliding brick that is pulled to the on or off position by electromagnets. When in the on position, it will close a circut. Thanks for the ideias.
"Don't do drugs or you'll end up like the people that made HURD."
-Linus Torvalds
EDIT: I probably can come up with the EBC bricks at my house.

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performaman's picture
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What happened to Evil Block Company(tm)?

Tom-
The forums don't automatically change "Lego" to read "Evil Block Company."
"Don't do drugs or you'll end up like the people that made HURD."
-Linus Torvalds

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jt
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BrickBits?

LOL! Great idea, the sliding colored block visuals and your building bits/kid's toy angle is a great twist on the concept, much better than wire-wrapped nails!

Have they got a fan part? . . . or can you use your PSU's hot air exhaust for a HoverBrick/air hockey deal for eliminating friction while the CPU is powered up and then using gravity and friction for maintaining the "Data integrity" of your nonvolatile (those bricks melt & burn tho! HEH!) "MASS" storage/RAM?

Now that I think about it, you might need to maintain the current to the electromagnets to hold the blocks in place, or are you already planning to use the live/dead circuits AS the RAM's logic state with the brick's physical position acting as nonvolitile storage? If that's the case, you could have an LED front panel display of the logic state wired in series to go with the sliding blocks.

jt Evil Block Company

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performaman's picture
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Not "real" RAM

This isn't for a computer as we think of them today. It's kind of a "re-enactment" of old storage methods. I plan to have a 2x4 brick sliding back and forth on those tile bricks. It won't be much more than 1cm away from the farthest magnet, and I plan to put 12v DC to the magnets (Too much?) There will be a piece of ferrous material (probably an iron nail) on each side of the slider. The magnets will turn off while the brick is in position and will only turn on to move it.
And I could put little Lego men on top of the bricks and make them dance.
"Don't do drugs or you'll end up like the people that made HURD."
-Linus Torvalds

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