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Can Anyone Identify this (Cold War?) Stuff?
An Anonymous Coward was left with some interesting pieces of hardware he would like some help identifying: "I work on the Yale Solar Racing Team. Recently we were cleaning out our electronics lab and found two ancient-looking boxes that, as the team legend says, originated in an ICBM somewhere and somehow got donated to us!"
"Can anyone tell us what these are:
- A Model 4006 PCM Decommutator (big white box, many toggle switches... it, apparently, decommutates things)
-
and
- A Model 760 Hybrid Data Measurement System (little orange box, connectors, no switches)
My first job after college used a "Remote Multiplexer/Demultiplexer" from Teledyne(?). Is this the same thing? IIRC this box was solid state (and large) and had additional capabilities, like sending out control signals during the cycle. Unfortunately it tended to overcycle by one instruction, meaning it would latch on things that were supposed to be latched off at the end of a sampling run. Many nights of fun with the oscilloscope.
And yes, by the time I worked on this box it was obsolete, in the mid-80's.
---- "If we have to go on with these damned quantum jumps, then I'm sorry that I ever got involved" - Erwin Schrodinger
ICBMs usually only have RF telemetry systems installed when they are being test launched from one of the ranges (Cape Canaveral or Vandenberg). The USAF does this on a regular basis. They pull a Minuteman missile from a silo, remove the nuclear weapons, add RF telemetry and range safety systems, and launch it from Vandenberg. If you see a film clip in a movie of an ICBM launch, it was probably one of these tests.
Mea navis aericumbens anguillis abundat
The model number is not familiar to me. Do you know the manufacturer?
I doubt that it is worth more than scrap. Most standalone PCM decommutators have been replaced with ISA or PCI cards that fit into a PC. These are made by Aydin, Avtec, L3 and other companies.
Some of the old PCM decommutators are interesting from a computer architecture point of view. They were very specialized computers that could process multi-megabit telemetry streams in real-time, using hardware built out of 7400 series TTL with magnetic core memory, running at a low (1 MHz ballpark) clock rate. A single instruction could input a telemetry word from a serial/parallel convertor and send it to multiple output devices. It was common to have multiple program counters, with each instruction having a field that specified which program counter to use for fetching the next instruction.
Mea navis aericumbens anguillis abundat
When the Herley.com webmaster is looking over the logs from the site on Monday -
35,000 hits on some obsolete piece of hardware's page...
Someone send the poor guy an email.
Jim
MMDC Mobile Media
-- My Weblog.
Herley-Metraplex has this to say about their fine orange-boxed Hybrid Data Measurement System:
"Integrates signal conditioning, calibration, analog and digital multiplexing, avionics bus monitoring, PCM encoding, and many other functions into one compact rugged package."
What we have here is a box that will sample a number of analog signals (up to 32 of them) and encode them into PCM digital signals.
Together with a commutator, the orange box would have been used to relay telemetry signals via radio from an ICBM, aircraft, kayak, bicycle or other craft, to patient listeners. A decommutator such as yours would decode the telemetry stream and some sort of display hardware (such as a computer) would interpret the telemetry, and produce photogenic graphs and charts for the pleasure of onlooking engineers with buzzcuts and pocket protectors.
Although it's distinctly possible that your boxes could have been used in an ICBM, they could also have been used in any other vehicle that incorporates electronics or cybernetic control systems. Aerospace is, however, the field where you'll find most of these vehicles. Have you checked to see if the boxes glow in the dark? That's always a good tell-tale sign of ICBM involvement. =]
PCM, as many Slashdotters know, stands for "pulse code modulation" and is the encoding technique used natively by your sound card. Your sound card is a fancy digital-to-analog converter whose job is to take PCM waveforms and convert them back into an analog signal which drives a speaker. The speaker vibrates, and out comes music, or speech, or whatnot.
Plug it in and hope it never works.
From http://www.herley.com/Herley-Metraplex/www/irigpcm .htm :
Early telemetry systems transmitted analog voltages using a commutator (rotary switch) at one end and a synchronized decommutator at the other end. We still use the words commutator and decommutator though most telemetry systems today use electronic switches and send digital data.
Could you at least post a link to some photos, so we can see what these look like?
:-)
:-)
Of course, a little orange box is probably just that.
But depending on what the size and style of connecters and switches look like, could tell some of us old geeks the approximate age of these boxes. The reality is probably that you have some ancient, worthless, non-functional, black-boxes. A decommutator is the receiving end of a commutator, a device for muxing analog signals. The pair would use two channels (either RF or wireline), one to keep the boxes in synch, one to pass the signals. Complex comm/decom units could pass dozens or hundreds of signals in a timesliced fashion. Great for remote telemetry where you just need the occasional sample of hundreds of voltages.
Sell them on e-bay, buy me a beer
the AC
Hemos is like...sci-fi fans;he thinks technology is cool, but he hasn't bothered to understand the science it's based on
... put these parts in a shoddy bomb casing, and trade it to some Lybian nationalists for some plutonium.
Does this mean that the Swedes have nukes?!
I have a buddy that was in this field during the cold war and even worked for "No Such Agency" for a while as well as working on the telemetry systems for the Mercury space program, and he says that a PCM decommutator basicly samples output from various devices and combines it into one output stream for telemetry. According to him your legend of it coming out of an ICBM is quite possible. You might get a good amount for it on ebay for it's historical value if you can tell people what it is. I hope this has helped you out.
Keep Austin Weird!
A simple goggle search found this.
72 CD D7 52 D0 7E D8 47 44 91 D5 84 D1 59 F1 A9-This is my 128bit integer. There are many like it, but this one is mine.
Another simple goggle search. "Hybrid Data Measurement System"
72 CD D7 52 D0 7E D8 47 44 91 D5 84 D1 59 F1 A9-This is my 128bit integer. There are many like it, but this one is mine.