What did you do before micro-controllers?

Mike2545

Hi all,
I have read though many posts and topics, there is one very interesting thread that discussed old school hackers. I was wondering what everyone else did before Basic Stamp came along and made our lives so much easier? I mean, if you needed a program controller what did you do?

I have this photo of a 'Program controller' that I made for a machine I built back in the day.

Bean

I remember my dad made a "toy" for me that was a heavy metal electrical box with rows of neon lights(green, red, orange) and one row of buttons.

Pressing the buttons would make different patterns on the lights. I remember it had a bunch of timers in it like the one in your picture.

I wish I had that thing now. But I'm sure I took it apart to see how it worked.

That was MANY years ago. My dad pasted away in 1979, but your post brought back one great memory. Thanks for posting it.

Bean.

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·The next time you need a hero don't look up in the sky...Look in the mirror.


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ElectricAye

Have you ever seen an antique player piano?
Ever seen the reeled perforated paper strips that loop past all of its pneumatic doo-hickeys?

Somebody once described to me a circa 1968ish space mission that was to send a vehicle as close to the sun as possible. Because electronics couldn't take the heat for long, it was to be flown completely by fluidic logic. I was told that they had machined an incredible number of little hydraulic valves that would work like fluidic transistors and the whole thing would work via logic circuits made for high temperature fluids. I always wanted to ask how the communication system worked - smoke signals maybe???




Post Edited (ElectricAye) : 2/5/2009 3:19:23 AM GMT

Mike2545

Bean, sorry to hear about your father, it sounds like he was very creative.

The cam assembly in the photo actuated micro-switches, which in turn powered relays, which then operated solenoid valves to actuate pneumatic cylinders.

Man, the hoops one had to jump through just to make a reliable system.

Mike2545

ElectricAye, yeah my buddy and I dragged home one when we were teenagers, it was foot pedal powered. I remember all of the tubing and the complex vacuum system that made the whole thing operate. We really worked up a sweat pumping the pedals making it play horribly out of tune.



Mike2545

kwinn

We used 74181's, some 8 register chip '172 I think, proms, and a counter chip.

Mike2545

Yeah, I have attempted to use the 74XX chips in this sort of design before and they work fine on the bench but when you take them in to the real world all sorts of things start to go wrong.
The electrical storm of noise that is generated by the compressors, relays, switches, & motors that are an integral part of the design, just make those chips go nutty half the time.

Mike2545

Beau Schwabe

Mike2545,

Glancing at that picture you posted from the picture icon, reminded me of a "mechanical cash register/adding machine" I took apart as a kid ... anyone ever take apart one of those? LOTS of ingenuity there.

Before micro-controllers? - I would use discrete logic and FPGA's ... lots of analog circuitry design.

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Beau Schwabe

IC Layout Engineer
Parallax, Inc.

ElectricAye

It seems to me that the artistry and complexity of some of the mechanical computers shoots some pretty big holes in the argument over whether silicon-based computers could someday reach some sort of consciousness. Obviously there are functions of our nervous system that operate on what appear to be simple modules, loops, etc. But I'm trying to imagine some kind of super-duper frictionless galactic-sized cash register ever cla-chunking enough bits around to achieve conscious awareness. Though they might, over eons, crank out incredible feats of computation, I just can't see how all those gears and levers, etc. would ever give rise to a sentient being. And silicon circuitry is just another way of cla-chunking the bits around, though maybe with less noise.

Marvin Minsky, Daniel Dennett, are you listening to this?

Phil Pilgrim (PhiPi)

My first digital computer, a Christmas gift from my folks, was a Brainiac K-30. It was purely electromechanical, comprised of six rotating wheels into which wipers could be affixed and which made contact with connecting strips screwed to the front and wired on the backside of the main panel. Output was via a row of 10 incandescent lamps. The most complicated thing I was able to make it do was play tic tac toe, based on a project from the instruction manual. Although sound in principal, it was rather cranky in practice due to the unreliability of the switch contacts. Nonetheless, it got me interested in computing at a very early age.

-Phil

Mike2545

After awhile of electromechanical based designs and purley for space saving design, I moved to TTL & DDL with some gate logic thrown in for good measure.
Of course, designing building and installing such complex control boards had major drawbacks. Any changes/upgrades had to be made with a soldering iron instead of a few lines of code.

Mike2545

Phil Pilgrim (PhiPi)

Fortunately for me, I was able to skip the hard-wired logic phase in my professional life. By the time I got around to doing hardware design (schooling was in physics and CS), micros had become firmly entrenched.

-Phil

RiJoRi

Before there was The Stamp, there were (a) other microcontrollers (8051-family, 6805-family, COP-8, HPC46000, etc.) and before them were (b) microprocessors (8080/8085, Z-80, 6800-family, etc.). There was also the Nat.Semi 8073 microprocessor with BASIC built in -- the EPROM would have the BASIC program in ASCII characters, and the 8073 would read it and execute the instructions. I still have a Cypher board and two or three BASICON boards laying around. And there was the BASIC-52, an 8052 with a built in BASIC interpreter.

I/O does not need IO port chips (8255, 6821, etc.). You could use 74x244s for input, and 74x373s for output. (Or was it a '377?)

--Rich

Mike2545

I never had the opportunity to work with any other microcontroller before.
I guess I chose the Stamp because I learned Basic when the first generation of personal computer came out.

Mike2545

Mikerocontroller

·· Thats my story too, Mike2545.·

Chris Savage

Rich, mine were 74LS244 for inputs and 73LS374 for outputs. 1 of each was sufficient to decode a C=64 keyboard (8 x 8 matrix). But as for the topic...before microcontrollers it was Forest M. Mims III and the Radio Shack kits such as the 150-in-1. Wooden box, spring clips for the wires...oh yeah.

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Chris Savage
Parallax Engineering

Mike2545

My very first circuit board was an actual board, with surface mount tube sockets, & fathenstock clips for up hooking power.

Mike2545

$WMc%

I remember back when I was a Kid,·~1980
I made a similar electro mechanical controller for a water softener that had been hit by lighting.I found the paper work from Callaghan on the softener, with a schematic. I robed the timer parts out of a RainBird irrigation controller. This was not a one or two evening project like we have now with the micros ($STAMPs). It took Me a while to make it all work.
It would have been Alot easier with a $stamp.

On a side note; If it was not for Forest M. Mims III and RadioShack, That project would have never happened, And I wouldn't be here on this post reply.

Like Mr.Savage, I to had that 150 in 1 Lab, and all the Engineers note books From Mr Mims and RadioShack. I learned so much from these labs and notes!

I want to thank RadioShack for their effort's back in the day!!!!, And hopefully Days to come.

_______________$WMc%____________________

RadioShack has Parallax senors in stores all across the USA!

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The Truth is out there············································ BoogerWoods, FL. USA

Post Edited ($WMc%) : 2/6/2009 3:03:22 AM GMT

kwinn

Mike2545, I think you misunderstood my reply. Those chips were used to build what would now be considered a primitive 4 bit micro. The 74181 was the arithmetic and logic unit, the '172 was the registers (8 if memory serves me), the counter was the program counter, and the prom was the program memory. I built the first one in high school for a science fair (the guy with the resistors/capacitors blinking neon bulbs won first prize). Used adaptations of that circuit for state machines until the 8080 came along and dropped in price to a reasonable level. Wish I had a better memory or had kept some of those early schematics, but I was busy trying to keep up.

stamptrol

Mike,

That drumswitch pic really took me back to the '70's when I had to use ones just like that to control the water treatment system in a large power plant. And, the throttle in an electric car I built in the early '80's used one too.

It strikes me funny that on Monday I'll be teaching a PLC course on a system that was introduced in late 2008. One of the commands which has been reworked and updated is the "drum" instruction which makes it easy to simulate that old-style electro-mechanical switch.

A real case of what's old is new again.

Cheers,

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Tom Sisk

http://www.siskconsult.com
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davejames

...wow!· "150-in-1".· That brought back some memories.

In that light, I found this on flickr:

http://www.flickr.com/photos/blazerman/2371910888/


Ah, those were the days.

DJ
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Dave Hein

I built a controller using a Z80 years ago.· I also built a controller using four AMD 2901 4-bit ALUs and a 2910 sequencer.· When I was a teenager I tried building a simple adding circuit using relays for logic gates.· I hand-made each relay, but I gave up after building a few relays.

I've always been fascinated by relay-logic, and it would be cool to build a simple add/subtract/multiply/divide calculator using relays.· Every button-ush would cause a clattering of relays.· That reminds me of the old mechanical calculators I used years ago.· Multiplies and divides were very noisy operations as the adding machine would churn through each decimal place.

Dave

Mike2545

kwinn,
I think I understood you, I just never had good performance/reliability out of the 74xx line. Those chips were power hungry and it seemed to me that electrical noise made some of them operate erratically. Oh I used them because that was what I had.
By the way I pulled my 1974 copy of the Signetics Data book off the bookcase and your memory is pretty good the '172 is an eight word two bit register.

Mike2545

Whit

My first electronic's kit was a Radio Shack Stobe Light...· Groovy!

I also built a Jacob's Ladder with a Model T Spark Coil.
I shocked myself so many times with that thing!

I still have a 300 in 1 Electronics Lab.

By the way, I was at Radio Shack the other day and they have Mim's Getting Started in Electronics again!

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Whit+


"We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney

Post Edited (Whit) : 2/7/2009 3:06:04 AM GMT

kwinn

Mike2545, thanks for confirming the chip. As to the reliability of the 74xx chips, if you had a good 5 volt supply they worked just fine. All of the computers I worked on (HP2100, HP21MX, Data General Nova, PDP11, PDS3, etc.) and the medical instruments used those chips. Reliability was not a problem as long as the heat was removed (think enough fans for a hovercraft). I have vivid memories of receiving a batch of 12 port serial interface boards for the HP2100 and having the computer refuse to boot when any one was installed. When I put the board up on my extender board and turned the computer on it vaporized a section of the extenders 5V trace. It turned out the ground and +5V planes were shorted on all 50 boards.

That HP power supply really surprised me though. It would put out 5V at 50amps day after day, and at about 55 amps would go into current limiting mode. Take the short off and the supply went back to 5 volts as if nothing had happened. I was impressed.

rjo_

I spent a lot of time asking myself... "I wonder how that works?"

Mike2545

Here is a link to a binary marble adding machine. Pretty cool.

www.break.com/index/marble-based-calculator.html

No Stamp involved...just gravity.

Mike2545