Relay Computer

C

Cosmic Software

Member
I have recently been looking at how I might be able develop something similar, either out of relays, such as either of these examples, or using Logic, or even out of transistors. I have started work already on certain parts of the microcontroller's structure, and it is truely fascinating.

Unfortunately, cost is going to be a big constraint when it comes to making whatever I design, but I can see just how beneficial this project could be to understand something that until now, I have considered to be black magic.
 
fernando_g

fernando_g

Senior Member
When somebody uses one of these little magic black boxes with pins we call a microprocessor, it is easy to forget that someone actually went and designed it at a sub-micron transistor level.

Using powerful computers if you will, but still a lot of work.
 
hippy

hippy

Ex-Staff (retired)
T

Tim036

Member
hippy said:
That must be the best described relay computer circuitry I've seen and I'm pretty impressed by the relative compactness of it all. I don't think I'd like to wire it up, and certainly not want to debug it !

Not sure what that blue tool is in the "The whole computer as of 6/8/07" photo but I suspect it's a cattle prod for coaxing it into operating.
Click to expand...
I came across an intelligent device running on compressed air.

It worked but was slow...........

Yes relays may perform a similar task but would fail to get to '42' in the lifetime of this universe ! IMHO.

Thankfully seriously slow systems are history

It took Microsoft until the mid to late 1990's to get to a usable Windows OS (arguable) and Window X for Linux a bit longer. (20 years after microprocessors arrived) [ Thankfully Apple was about with the Mac]

Relays have their place in control systems but not a logic systems unless you fear nuclear flash in your locality !

Tim
 
fernando_g

fernando_g

Senior Member
hippy said:
Not sure what that blue tool is in the "The whole computer as of 6/8/07" photo but I suspect it's a cattle prod for coaxing it into operating.
Click to expand...
It is a spring loaded vacuum solder puller.
It actually works great in sucking out solder which one has previously liquified with an iron. After three or four pulls though, one has to unscrew it and remove all the solder debris inside.

Not for SMT devices, though... it would suck out the device along with the solder.
 
S

slurp

Senior Member
While you could hardly call it a computer, Network Rail has a huge array of relay logic supporting the UK's railway signalling system. A complex system built on simple building blocks that allows Signallers to "program" routes for the passage of trains, interlocking agaist conflicts, tracking trains and cancelling the routes as they pass throught them.

They're slowly giving way to solid state technology but some of these systems have seen 40 years of service and contain thousands of relays - something that's interesting to listen to as they relays tick and click through their patterns of operation.

As we get back to the Victorians, the old mechical boxes implemented the AND, OR & NOT logic in mechanical form to ensure that conflciting routes could not be set.

I guess there's nothing really new, it's all in the application.

regards,
Colin
 
R

Ruzzz

Member
Up until about 15 years ago the main output BBC1 and 2 went through strowger switches. http://en.wikipedia.org/wiki/Stepping_switch
This was replaced with video relays which are now beyond their service life and no one will put up the money to replace "cos its old analogue stuff, and will be switched off in three years" which means you cant touch the bay that the equipment is in because any vibration causes more problems.
 
W

westaust55

Moderator
Cosmic Software said:
I have recently been looking at how I might be able develop something similar, either out of relays, such as either of these examples, or using Logic, or even out of transistors. I have started work already on certain parts of the microcontroller's structure, and it is truely fascinating.

Unfortunately, cost is going to be a big constraint when it comes to making whatever I design, but I can see just how beneficial this project could be to understand something that until now, I have considered to be black magic.
Click to expand...
@Cosmic,
do a search on the internet for Educ-8 if for nothing more than your general interest.
A discrete logic IC based microcomputer designed by Electroncis Australia in the 1970's. Plent of information out there and still folks building clones from what I last read.
 
R

Rickharris

Senior Member
fernando_g said:
Not really a PICAXE topic, but I thought that users here would find it quite interesting, if not outright fascinating, that there are hardcore computer geeks that build computers with relays.

http://www.electronixandmore.com/project/relaycomputertwo/index.html
Click to expand...

RELAYS! Poo modern stuff - May I direct you to the details of the rope based computer http://books.google.co.uk/books?id=0Rb5jBg6sJwC&pg=PA117&lpg=PA117&dq=rope+computer+Scientific+american&source=bl&ots=UGTKZz3d7a&sig=aIxaiahNZVxZwTjHe77ztOTpFIk&hl=en&ei=CollSomVEd64jAfo6ZGWAQ&sa=X&oi=book_result&ct=result&resnum=1

Enjoy and get that string out!
 
W

Wrenow

Senior Member
Hmmm. Relay based computers. I remember as a youth going with a friend to his Explorer Scout meeting, sponsored by one of the IBM Processing centers in Dallas (circa 1966?) to have a relay cleaning party, where we cleaned the relay contacts in one of their older machines with a burnishing tool. Their newer machines had ferrite core memory, as I recall. And drum drives that could store thousands of bytes of information - amazing stuff at the time.

Cheers,

Wreno
 
fernando_g

fernando_g

Senior Member
And of course, let's not forget the Bombes, the original electromechanical dechipering machines used to break the Nazi Enigma codes during WW2.
 
R

Rickharris

Senior Member
Wrenow said:
Hmmm. Relay based computers. I remember as a youth going with a friend to his Explorer Scout meeting, sponsored by one of the IBM Processing centers in Dallas (circa 1966?) to have a relay cleaning party, where we cleaned the relay contacts in one of their older machines with a burnishing tool. Their newer machines had ferrite core memory, as I recall. And drum drives that could store thousands of bytes of information - amazing stuff at the time.

Cheers,

Wreno
Click to expand...
The ICL system 4 machines I first worked on in the 80's had core store and drums, a 256 Mb dick pack was all I could lift!

Teletype input/output and paper tape, punch cards and mag tape mass storage 15 of them.
 
Peter M

Peter M

Senior Member
A "crossbar" telephone exchange was another good example of a relay computer.... and yes they were very cumbersome to wire up and maintain.

I was amazed at some of the guys that used to look after these computers, they could litterally hear a problem and get pretty close to the problem just by following the sound.

I was also amused by the people that said these were an analogue exchange.... a relay is on or off????
Hmmm, thats binary isn't it? :confused:

Removed the last I know of about ten years ago.

Old Pinnies are another good one... Got to have steel balls to fiddle with these though! :eek:
 
Peter M

Peter M

Senior Member
Brietech - no they actually beleived that because a relay was mechanical it had to be analog, but I understand what your saying, the signal transferred by the relay contacts was most certainly analog (well mostly - voice)
 
premelec

premelec

Senior Member
must be pin ball machines - incorporating relays, lights and rolling balls... :)
 
Last edited:
R

RobertN

Member
Machine tools used to use relay logic for some fairly complex machining. Some used automotive type alternators for a power source and optical encoders to measure speed. That's about all I remember from nosing around the machine and maintenance shop 40 years ago. Many used ladder logic programming which is still around
 
S

slurp

Senior Member
Brietech said:
It cracks me up how many times a forum member in the US (myself included!) needs a translation of something british or australian =)
Click to expand...
Maybe but Pinnies might have been short for Pinafore [dress] and when we have trouble with the "old pins" it's a leg problem :)

Now if we all used English.... we'd loose the variety that make life interesting :rolleyes:

regards,
Colin
 
B

BeanieBots

Moderator
In the UK, nobody would think anything of it if someone said,

"I'm just going to slip on a pull-over and pop out for a fag."

Might raise a few eyebrows if they said that in the US!
(put on a jumper and go out for a cigarette in case anyone isn't too sure.)
 
D

Dippy

Moderator
"Now if we all used English.... we'd loose the variety that make life interesting"

- that's a classic :)
 
You must log in or register to reply here.
Top