Developing The First ICs In Orbit

Over six decades of integrated circuit production we’ve become used to their extreme reliability and performance for a very reasonable price. But what about those first integrated circuits from the early 1960s? Commercial integrated circuits appeared in 1961, and recently Texas Instruments published a fascinating retrospective on the development of their first few digital ICs.

TI’s original IC product on the market was the SN502, a transistor flip-flop that debuted at $450 (about $4100 today), which caught the interest of NASA engineers who asked for logic functions with a higher performance level. The response was the development of the 51 series of logic chips, whose innovation included on-chip interconnects replacing the hand interconnects of the SN502. Their RCTL logic gave enough performance and reliability for NASA to use, and in late 1963 the Explorer 18 craft carried a telemetry system using the SN510 and SN514 chips into orbit. 52 and 53 series chips quickly followed, then in 1964 the 54 series TTL chips which along with their plastic-encapsulated 74 series equivalents are still available today.

Considering that in 1961 the bleeding edge of integrated circuit logic technology was a two-transistor chip with hand interconnects, it seems scarcely conceivable that by ten years later in 1971 the art had advanced to the point at which the first commercially available microprocessors would be produced. It’s unlikely that many of us will stumble upon any of the three-figure SN1-series logic chips, but to read about them is a fascinating reminder of this pivotal moment in the history of electronics.

Header: Mister rf, CC BY-SA 4.0.

19 thoughts on “Developing The First ICs In Orbit

  1. One can’t help being struck by the similarities of those first ICs and modern SMDs. I wonder how they came to go from surface-mount to through-hole? Difficulties with mass production?

      1. Not based on the other photos in the linked article – it looks like they left the leads long and straight and soldered them to a carrier board to bring them out.

      2. Because early ICs were so expensive and since one the main points of making them was reduced size and weight for overall system weight and size reduction they were used mainly for aerospace systems where their cost was justified and SMT techniques were used. For example, the Apollo Guidance Computer used SMT ICs. Consumer electronics did not require SMT nor could they even remotely afford to use these ICs.

      3. Not through hole. They were soldered on the side they were placed. If i had to guess, the length had to do with strength in less than friendly environments, vibration etc. Also some of these ran fairly hot and were pretty densely packed in a system. Hughes used these sort of packages with a bend like the gull wing of current use, but longer so that a metal strip (read very long heat sink) could be run under the whole row of chips.

    1. Have you ever opened a commercial product of that era?
      A lot of stuff in the 60’s was still tube-based and not seldomly used point to point wiring.

      Mass manufacturing of electronics was partially still done by hand and not at all ready for miniaturization like this.
      Things changed fast after that, but it would no be until the late 80’s that SMD really started to become commonplace.

      There are more then enough people today that still fear surface mount components. Or “grains of sand” as a friend likes to call them ;)

    2. I don’t think “surface mount” arrived till later, though yes, these did the same thing.

      I remember comments in the magazines about these not being so useable, in the late sixties or early seventies when flatpack ICs were hitting the surplus market.

      1. In 1969 or so my dad built a receiver calibration frequency reference with RTL(?) flip flops in packages like this one. It used a PCB made with rub-on transfers as etch resist and was hand soldered. Not bad for someone who had no previous surface mount soldering experience and had done a lot of work with 50kW power tubes!

  2. >Considering that in 1961 the bleeding edge of integrated circuit logic technology was a two-transistor chip with hand interconnects, it seems scarcely conceivable that by ten years later in 1971 the art had advanced to the point at which the first commercially available microprocessors would be produced.
    It’s pretty much a standard application of Moore’s law. 10 years advancement, doubling density every year (things slowed down later) resulted in the 2250 transistor 4004. Look at what we’re up to today, with single chips containing 100’s of billions of transistors.

    1. Except there’s nothing fundamental about Moore’s Law. It was formulated purely as an observation of precisely this data (so the law fits it by *definition*, not application) and subsequently was used as a development target by the industry, becoming a self-fulfilling prophecy.

      The photolithographic process for making ICs is so incredibly scalable that we were more limited by the work needed to design new chips, build the infrastructure to make them, and develop the markets to deploy them; the technology itself was no longer a bottleneck.

    2. Except this wasn’t really an integrated circuit. From what I can gather, the 51x series was constructed from individual die that were hand wired together in the package. No doubt, the same was true of the SN501. So Moore’s Law doesn’t really apply.

  3. I was a test engineer on the Minute Man guidance computer in the early 60’s when these were first used. The D17 was all discrete components, and about the size of a large trash can. The D25 with IC’s was more like a large shoe box. The chips were hand soldered on small multi-layer boards. Multi-layers were a new thing and there were problems with interlayer connections. We were told that each board was worth the price of a new Cadillac.

  4. I was at a Ham Fest a decade or so ago and I saw all these bright color packs with gold chips in them and asked “How much?”. “You can have those things!” said the old-timer. They were all early TI SN and SNR (I think Radiation hardened or Ruggedized?). I still have two – an SNR 516B and an SNR518B. The rest I sold to collectors.

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