6 ms·

“Space age electronics”: Inside a GE thin-film paperweight from the 1960s

151 points by parsecs 5y ago

kens 5y ago
Author here if anyone has questions...
- Cerium 5y ago
  I love that it is a literal paperweight and not simply a relic. Thank you for the fun read.
- mustacheemperor 5y ago
  Thanks for the great write up! Any chance this thing still works? I imagine it may require some modification either way because of the oldschool battery.
  - kens 5y ago
    The paperweight worked after I fixed a broken wire and powered it from a power supply, and it generated the beeping sound. However, after I re-assembled it, it switched to an annoying fast-beep. I don't know if a component failed or I messed something up during assembly. You can hear the beeping here: https://twitter.com/kenshirriff/status/1411032440534028289 https://twitter.com/kenshirriff/status/1411032440534028289
  - tyingq 5y ago
    >I imagine it may require some modification either way because of the oldschool battery. It's a 22.5v ANSI/NEDA 215, and they still make them. Alkaline now instead of Zinc-Carbon. They are kind of expensive, at $20+ USD, but available.
- betamaxthetape 5y ago
  A great "tear down" of a really interesting device. I'd be curious how you ended up with this? I'm sceptical that the satellite is Ariel 1 or Ariel 2 for two reasons: (a) Ariel was the British satellite programme, and I think that General Electric would have based the design on an American satellite. (b) Ariel 2 was build by Westinghouse, a rival to GE. My guess would be that it's a generic design, but I would love to hear an update if you find out for sure. (I'm interested in the Ariel satellites, particularly Ariel 3, since I've ended up with a few of the original Ariel 3 telemetry tapes from the STADAN tracking stations. Still trying to work out a viable way to read / understand them...)
  - kens 5y ago
    The paperweight was loaned to me for analysis. It's pretty cool that you have Ariel 3 telemetry tapes. I agree that the satellite in the paperweight isn't Ariel, but Ariel was the most similar satellite I could find. I'm hoping someone will find a satellite that is a better match. But it could be some obscure proposed satellite that was never built.
  - jacquesm 5y ago
    What kind of physical format do those tapes have?
    - betamaxthetape 5y ago
      They are half-inch wide 7-track tapes. It's the 7-track bit that makes them difficult to read (I have a half-inch machine but it's 8-track). I think it was NASA and a few other government agencies using this 7-track format (or 1-inch 14-track), rather than the 1/2-inch 8-track / 1-inch 16-track used in audio studios. The workflow for these tapes is described on the Chilton Computing website [1]. (Note: this is analogue 7-track, not to be confused with the digital 7-track format used by early IBM mainframe machines). [1] http://www.chilton-computing.org.uk/acl/applications/satellite/p003.htm http://www.chilton-computing.org.uk/acl/applications/satelli...
      - jacquesm 5y ago
        There is a Teac 1/2 " that does 8 tracks, you could probably read them one track at the time by judiciously jiggling the height of the head relative to the base of the player. The heads are narrower than a single track so that should work. The analog format is likely simple FSK or some variation on that theme. It would take 7 passes to get it off assuming only one of the heads lines up with a track at any given time. Keeping the sync between the tracks will be the hard part. I'm in Europe so that probably rules out collaboration on this but if there is some way to get me a sample of such a tape I'll be more than happy to give it a shot. edit: this machine: https://soniccircus.com/product/teac-80-8-1-2-8-track-analog-recorder/ https://soniccircus.com/product/teac-80-8-1-2-8-track-analog...
- ipsum2 5y ago
  Could you record a clip of the sound?
  - kens 5y ago
    You can hear the beeping here: https://twitter.com/kenshirriff/status/1411032440534028289 https://twitter.com/kenshirriff/status/1411032440534028289
sensorsbroken 5y ago
Makes you wonder what's possible in 2021 in the age of light sails and uncommoditized nanoelectronics. What is SOTA for 2D semiconductors (e.g. MoS2 with bismuth) in production?
jtchang 5y ago
Why gold wires instead of copper?
- deleted 5y ago
  [deleted]
- kens 5y ago
  Gold wires were used for bonding in integrated circuits too. I think because gold is much more ductile, so you can make thin wires that won't break. It's also more resistant to corrosion, which is a problem with copper wire.
  - pfdietz 5y ago
    Doesn't copper interact badly with silicon?
    - kens 5y ago
      I don't know about copper-silicon interactions, but normally you'd bond to a metal pad, not to silicon directly. For a while, the "purple plague" was a problem when gold bond wires reacted badly with aluminum bond pads, forming a purple compound. https://en.wikipedia.org/wiki/Gold%E2%80%93aluminium_intermetallic https://en.wikipedia.org/wiki/Gold%E2%80%93aluminium_interme...
  - jacquesm 5y ago
    The fact that it is more ductile probably also helps with the welding process.
- syntaxing 5y ago
  A lot of high performance chips like hybrids (the chip, not cars) are gold bonded. Mainly because its a good conductor and super inert (metal behave funny in contact in space, oxygen is earth's "memory" after all).
  - AnimalMuppet 5y ago
jacquesm 5y ago
Impressive how little that battery leaked over all those years. And funny how the transistors have an extra wire coming out of them, but those are all paired and run to the same terminal, I wonder what's up with that. The beeper is one of those crystal (piezo) earphones with part of the bit that you would stick in your ear cut off.
- kens 5y ago
  The two wires are probably for reliability and/or current capacity.
  - jacquesm 5y ago
    Right, so they're either emitter or collector. Base would then be the single wire left over and the counterpart the big terminal bonded directly to the thin film circuit. Beautiful bit of history, thank you very much for taking the time to do this one.
    - morcheeba 5y ago
      But matching the schematic to the picture, the double wires are on the base. It makes me think it's a double-base transistor, but both bases tied together because they don't need two for this circuit. If it was for reliability, I'd expect the emitter to also be doubled, but it has a single wire. GE made the 3N36/37, but here's a datasheet for a similar part: http://bitsavers.org/components/ti/discrete/transistors/3N34.pdf http://bitsavers.org/components/ti/discrete/transistors/3N34...
      - jacquesm 5y ago
        That means it is definitely not for current. The current to the base would be negligible compared to the EC current.
- tyingq 5y ago
  It would have been a zinc-carbon battery[1]. I'm also very surprised that it's not corroded. [1] https://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery https://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery
denton-scratch 5y ago
Cordwood was mentioned here, a couple of weeks ago: https://news.ycombinator.com/item?id=27531379 https://news.ycombinator.com/item?id=27531379 The one in the photo in your article has a much denser collection of components in it than the cordwood gate that I remember. There was a lot of air in that gate.

151 points by parsecs 5y ago

kens 5y ago

Author here if anyone has questions...

Cerium 5y ago
I love that it is a literal paperweight and not simply a relic. Thank you for the fun read.
mustacheemperor 5y ago
Thanks for the great write up! Any chance this thing still works? I imagine it may require some modification either way because of the oldschool battery.
- kens 5y ago
  The paperweight worked after I fixed a broken wire and powered it from a power supply, and it generated the beeping sound. However, after I re-assembled it, it switched to an annoying fast-beep. I don't know if a component failed or I messed something up during assembly. You can hear the beeping here: https://twitter.com/kenshirriff/status/1411032440534028289 https://twitter.com/kenshirriff/status/1411032440534028289
- tyingq 5y ago
  >I imagine it may require some modification either way because of the oldschool battery. It's a 22.5v ANSI/NEDA 215, and they still make them. Alkaline now instead of Zinc-Carbon. They are kind of expensive, at $20+ USD, but available.
betamaxthetape 5y ago
A great "tear down" of a really interesting device. I'd be curious how you ended up with this? I'm sceptical that the satellite is Ariel 1 or Ariel 2 for two reasons: (a) Ariel was the British satellite programme, and I think that General Electric would have based the design on an American satellite. (b) Ariel 2 was build by Westinghouse, a rival to GE. My guess would be that it's a generic design, but I would love to hear an update if you find out for sure. (I'm interested in the Ariel satellites, particularly Ariel 3, since I've ended up with a few of the original Ariel 3 telemetry tapes from the STADAN tracking stations. Still trying to work out a viable way to read / understand them...)
- kens 5y ago
  The paperweight was loaned to me for analysis. It's pretty cool that you have Ariel 3 telemetry tapes. I agree that the satellite in the paperweight isn't Ariel, but Ariel was the most similar satellite I could find. I'm hoping someone will find a satellite that is a better match. But it could be some obscure proposed satellite that was never built.
- jacquesm 5y ago
  What kind of physical format do those tapes have?
  - betamaxthetape 5y ago
    They are half-inch wide 7-track tapes. It's the 7-track bit that makes them difficult to read (I have a half-inch machine but it's 8-track). I think it was NASA and a few other government agencies using this 7-track format (or 1-inch 14-track), rather than the 1/2-inch 8-track / 1-inch 16-track used in audio studios. The workflow for these tapes is described on the Chilton Computing website [1]. (Note: this is analogue 7-track, not to be confused with the digital 7-track format used by early IBM mainframe machines). [1] http://www.chilton-computing.org.uk/acl/applications/satellite/p003.htm http://www.chilton-computing.org.uk/acl/applications/satelli...
    - jacquesm 5y ago
      There is a Teac 1/2 " that does 8 tracks, you could probably read them one track at the time by judiciously jiggling the height of the head relative to the base of the player. The heads are narrower than a single track so that should work. The analog format is likely simple FSK or some variation on that theme. It would take 7 passes to get it off assuming only one of the heads lines up with a track at any given time. Keeping the sync between the tracks will be the hard part. I'm in Europe so that probably rules out collaboration on this but if there is some way to get me a sample of such a tape I'll be more than happy to give it a shot. edit: this machine: https://soniccircus.com/product/teac-80-8-1-2-8-track-analog-recorder/ https://soniccircus.com/product/teac-80-8-1-2-8-track-analog...
ipsum2 5y ago
Could you record a clip of the sound?
- kens 5y ago
  You can hear the beeping here: https://twitter.com/kenshirriff/status/1411032440534028289 https://twitter.com/kenshirriff/status/1411032440534028289

sensorsbroken 5y ago

Makes you wonder what's possible in 2021 in the age of light sails and uncommoditized nanoelectronics. What is SOTA for 2D semiconductors (e.g. MoS2 with bismuth) in production?

jtchang 5y ago

Why gold wires instead of copper?

deleted 5y ago
[deleted]
kens 5y ago
Gold wires were used for bonding in integrated circuits too. I think because gold is much more ductile, so you can make thin wires that won't break. It's also more resistant to corrosion, which is a problem with copper wire.
- pfdietz 5y ago
  Doesn't copper interact badly with silicon?
  - kens 5y ago
    I don't know about copper-silicon interactions, but normally you'd bond to a metal pad, not to silicon directly. For a while, the "purple plague" was a problem when gold bond wires reacted badly with aluminum bond pads, forming a purple compound. https://en.wikipedia.org/wiki/Gold%E2%80%93aluminium_intermetallic https://en.wikipedia.org/wiki/Gold%E2%80%93aluminium_interme...
- jacquesm 5y ago
  The fact that it is more ductile probably also helps with the welding process.
syntaxing 5y ago
A lot of high performance chips like hybrids (the chip, not cars) are gold bonded. Mainly because its a good conductor and super inert (metal behave funny in contact in space, oxygen is earth's "memory" after all).
- AnimalMuppet 5y ago

jacquesm 5y ago

Impressive how little that battery leaked over all those years. And funny how the transistors have an extra wire coming out of them, but those are all paired and run to the same terminal, I wonder what's up with that. The beeper is one of those crystal (piezo) earphones with part of the bit that you would stick in your ear cut off.

kens 5y ago
The two wires are probably for reliability and/or current capacity.
- jacquesm 5y ago
  Right, so they're either emitter or collector. Base would then be the single wire left over and the counterpart the big terminal bonded directly to the thin film circuit. Beautiful bit of history, thank you very much for taking the time to do this one.
  - morcheeba 5y ago
    But matching the schematic to the picture, the double wires are on the base. It makes me think it's a double-base transistor, but both bases tied together because they don't need two for this circuit. If it was for reliability, I'd expect the emitter to also be doubled, but it has a single wire. GE made the 3N36/37, but here's a datasheet for a similar part: http://bitsavers.org/components/ti/discrete/transistors/3N34.pdf http://bitsavers.org/components/ti/discrete/transistors/3N34...
    - jacquesm 5y ago
      That means it is definitely not for current. The current to the base would be negligible compared to the EC current.
tyingq 5y ago
It would have been a zinc-carbon battery[1]. I'm also very surprised that it's not corroded. [1] https://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery https://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery

denton-scratch 5y ago

Cordwood was mentioned here, a couple of weeks ago: https://news.ycombinator.com/item?id=27531379 https://news.ycombinator.com/item?id=27531379 The one in the photo in your article has a much denser collection of components in it than the cordwood gate that I remember. There was a lot of air in that gate.