Computer RAM without RAM.

Dimitri · Super Member Joined: Nov 25, 2005 Posts: 5946

So I was doing Pneumatics at my college, and we were discussing relays, (have been actually since the start of the term). And I got to thinking I could make relays work as memory modules in a computer system.

After all they are on-off, and although we can use relays that have stay on features after the power goes out on it, I couldn't find anything small enough, but I found these little relays that fit in a 14-DIP socket so I decided to use them.

My first design showing 2 rows (ie 2 bytes) of data:

Close up of the system:

As you can see, I used 2 transistors to allow easier power up of the relays, although they do not require much power to turn on, I figured if I had assembled these onto boards, such as in a STD Bus computer, I may have issues with the ability of the processor to switch on the relay, hence the transistor shifting done in the above pictures.

For simplicity's sake I decided not to show the relay's switch that actually produces a data value when being read. Which consists of a transistor and the switch in series, when the CPU is reading one byte of data, all the transistors would turn on, and with the relay switch being active, it would feed the CPU the values stored in the relays.

If that turned out to not be a problem, then I could go with a simplified system set up:

So only the relay, one transistor, and one NC switch is required.

Although probably only useful for very slow computer systems (1Mhz tops most likely if not in the Khz range. Confused

), I've always wondered how to make a macro version of memory and I think this is it, add a bunch of LED's to the Data out lines of the relays, and you can amaze people as they quickly switch on and off.

However due to the nature of the units, it would "eat up" quite a bit of PCB space to get the system holding any decent amount of Data. When I get some time I'll model it on some PCB software to see how much data I could possibly fit into a STD card size. Might make for a good "demo" system, to show people physically what a computer does with its 1's and 0's on memory media.

PS. If you noticed I didn't spec out the transistors, not sure which ones would be best for this application.

Dimitri

Elvis · Posted: Tue Nov 23, 2010 11:32 pm Post subject: Re: Computer RAM without RAM.

You have too much spare time on your hands D Very Happy

go hunting at once young man and clear your head...

Pumpkinslinger · Posted: Wed Nov 24, 2010 12:10 am Post subject: Re: Computer RAM without RAM.

Congratulations, you've reinvented the wheel... Wink

But it could be a fun project.

PaulS · Posted: Wed Nov 24, 2010 1:33 am Post subject: Re: Computer RAM without RAM.

Now, if you can get them mass produced on a wafer 1mm square we can all have new computers that leak air on our desks..... Smile

gelandangan · Posted: Wed Nov 24, 2010 2:12 am Post subject: Re: Computer RAM without RAM.

Ok, yeah, you got too much time on your hand Mr. D

So you are building a bunch of RS latches..
Ok no specs for the transistors, but are they NPN or PNP bunch you are going to use?
It would be a big difference in the operation by pulling up or pulling down the base pin.

Instead of the bunches of transistors and relays, would using SCR counted as cheating?
I reckon they would clear up the board a bit Razz

Vince · Posted: Wed Nov 24, 2010 5:27 am Post subject: Re: Computer RAM without RAM.

Elvis wrote:

You have too much spare time on your hands D Very Happy

go hunting at once young man and clear your head...

I gotta agree Elvis...however...let us not stifle the urges of wisdom of the young.

As an aside 'Mitri...MY BLOODY HEAD HURTS NOW, YA BUGGER. I'm gonna have a beer. Very Happy

Cheers, Vince

radar · Posted: Wed Nov 24, 2010 4:49 pm Post subject: Re: Computer RAM without RAM.

Ow my brain hurts just looking at it, initailly I thought its was a road map from somewhere in the wheat or corn belt. GO HUNTING!

Dimitri · Super Member Joined: Nov 25, 2005 Posts: 5946

You think I have a lot of time on my hands, this came to me as I was eating lunch at the college between classes. Decided that I'd make drawings of my idea I had in my head. I have not had a day off since the middle of September. Sad

PaulS wrote:

Now, if you can get them mass produced on a wafer 1mm square we can all have new computers that leak air on our desks..... Smile

No air leaks, just was thinking of relays due to the electro-pneumatic class, however I was not considering using air lines to the system. Very Happy

And yes SCR's would be cheating. But they'd all be NPN transistors, as PNP transistors are slower and I don't want to add more delays then the relays already do. Very Happy

Dimitri

Pumpkinslinger · Posted: Wed Nov 24, 2010 6:48 pm Post subject: Re: Computer RAM without RAM.

I think using the transistors is cheating, it should be ALL relays...

Dimitri · Super Member Joined: Nov 25, 2005 Posts: 5946

At that point I may as well use vacuum tubes. Laughing

Dimitri

44marty · Posted: Wed Nov 24, 2010 10:14 pm Post subject: Re: Computer RAM without RAM.

So you're trying to reinvent "UNIVAC" ? Isn't that a giant step backwards?

Dimitri · Super Member Joined: Nov 25, 2005 Posts: 5946

For one to understand electronics, above the superficial level (which I can already do, ie microcontrollers, modern computer hardware etc), going really far backwards and breaking it down to smaller componates sometimes is the only way to eventually move more forward.

After all if I don't break down the system to small bits and pieces, I will never know what is "really" happening. Its a shame though I don't have 70 years to reinvent the whole process and then discover something new faster then everyone else. Laughing

Dimitri

Elvis · Posted: Wed Nov 24, 2010 11:01 pm Post subject: Re: Computer RAM without RAM.

time between classes should be being spent dreaming of going hunting/fishing or in the pursuit of all those lovely lasses all around you... man it was great back in the education days...

Dimitri · Super Member Joined: Nov 25, 2005 Posts: 5946

Girls are great, but I am dating one, so my mind is free to work on other projects between classes Smile

Dimitri

gelandangan · Posted: Thu Nov 25, 2010 12:10 am Post subject: Re: Computer RAM without RAM.

Um Mr D.
you ought to spend the idle time dreamin' on how to make them girls happy..
or some productive stuff like how to paint the dean's office pink overnight..

Abacus can be counted as the original RAM - so there.. no silly-con..