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Similarly to

what was the first TTL proper integrated circuit or chip in space (includes suborbital flights) and to orbit or beyond?

Was it a Texas Instruments 7400 series or something that predates those?

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According to "Military Implications of the Transfer of Semiconductor Technology to the USSR", the Minuteman II used "monolithic TTL" integrated circuits https://www.cia.gov/readingroom/docs/DOC_0000969810.pdf

These were likely custom TTL chips made by Texas Instruments, predating the military 5400 version of the 7400 family.

Whic ICBMs don't go into orbit (well sometimes...), they definitely go into space in suborbital trajectories.

The first Minuteman II missile was launched September 24, 1964.

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  • $\begingroup$ Gemini 1 was launched April 8 1964, 4 months earlier. $\endgroup$
    – Uwe
    Jul 12 at 21:10
  • $\begingroup$ @Uwe But did it use TTL chips? $\endgroup$ Jul 12 at 21:19
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    $\begingroup$ Gemini used RTL, Minuteman may have used TTL gates from Sylvania made 1963. $\endgroup$
    – Uwe
    Jul 12 at 21:53
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    $\begingroup$ Gemini used RTL logic built with discrete components, no chips. $\endgroup$
    – Uwe
    Jul 13 at 19:45
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The Apollo guidance computer was built with RTL logic. RTL was followed by DTL and later by TTL.

The Apollo guidance computer used only a dual three input NOR gate.enter image description here

Integrated RTL logic was introduced 1961, DTL 1962 and TTL 1963.

The Gemini computer was built without integrated circuits, only discrete components, see Computers in Spaceflight: The NASA Experience.

The 5400 And gate was introduced 1964, the 7400 1966. 5400 was the military temperature range, 7400 the commercial range.

So the first logic chip used in space was RTL, not TTL.

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    $\begingroup$ Helpful picture: static.righto.com/images/agc-rope/nor-schematic.png $\endgroup$
    – DrSheldon
    Jul 13 at 1:28
  • $\begingroup$ @DrSheldon: I wonder why the schematic is drawn with the pins in that order? If one were to draw the schematic with pins in order 10-1-2-3-4-5 counter-clockwise on the left side, and 5-6-7-8-9-10 on the right, the pinout would make a lot more sense. $\endgroup$
    – supercat
    Jul 13 at 17:37
  • $\begingroup$ @supercat: It is rather odd. They could have done a better job conveying the symmetry of the chip. The power pins (5 and 10) should appear only once, and connect the two sides. $\endgroup$
    – DrSheldon
    Jul 13 at 21:12
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    $\begingroup$ @Uwe: Swapping pins 10 and 1 on the left side to match the physical orientation and extending the common-emitter wire on the right side leftward would have allowed the two pin-10 connections to be adjacent, and likewise the two pin-1 connections, even if all the transistor orientations were left alone. $\endgroup$
    – supercat
    Jul 14 at 14:40
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    $\begingroup$ @Uwe: Power and ground pins are only inputs and outputs if a device is intended to respond to changes in the power that's available to a device, or control the flow of current to other devices. As for the "rule", it's a guideline which is followed when there is no compelling reason to favor one direction over the other, but which often gives way to other considerations. $\endgroup$
    – supercat
    Jul 14 at 15:33
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According to Computers in Spaceflight, the Voyager Attitude Articulation and Control System Computer.

Dubbed "HYPACE," for Hybrid Programmable Attitude Control Electronics, it was a byte-serial processor with substantial power. Using the same 4K, 18-bit-wide plated-wire memory from the Viking Orbiter computer, HYPACE added transistor-transistor logic (TTL) medium-scale integrated circuits to create a relatively fast (28-microsecond cycle) processor with index registers for addressing. Byte-serial architecture was possible because the TTL chips were designed for 4-bit parallel operation, so the 18-bit words could be moved around in five cycles instead of the 18 a serial machine would need, increasing overall speed. Index registering meant that the same block of code could be used for all three axes, reducing memory requirements. It appeared that the attitude control systems of future spacecraft would almost certainly benefit from such a computer. Voyager was the first to do so, due to new requirements.

p. 177


The program for the Apollo Guidance Computer was woven into core rope memory. Because this was a very labor-intensive process, a simulator replaced the core memory unit while the software was being developed. This simulator used 7400-series TTL logic, although it never actually flew in space.

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