> On Jul 30, 2026, at 7:16 AM, Tony Duell via cctalk <[email protected]>
> wrote:
>
> On Thu, Jul 30, 2026 at 12:05 PM Christian Corti via cctalk
> <[email protected]> wrote:
>>
>> On Wed, 29 Jul 2026, Carey Schug wrote:
>>> i wondered, and ai confirmed, that vacuum tube computers likely
>>> contained asbestos, but suggested in the vacuum tubes, so probably not
>>
>> Go back to school and learn the old-fashioned way. Never trust AI, always
>> verify the results.
>> Asbestos _in_ vacuum tubes ... *lol*
>>
>
> Perhaps you should learn the very old-fashioned way of valves/vacuum tubes :-)
> There were some very early triodes that deliberately contains residual
> gas. See here
>
> https://www.museumoftechnology.org.uk/objects/_expand.php?key=954
>
> There was a little side/top tube containing asbestos that you heated
> to release some of said gas that was adsorbed onto the asbestos.
>
> So yes, some valves _do_ contain asbestos. But it would only be a
> hazard if the glass was broken.
>
> And if such a valve was ever used in any DEC computer or peripheral I
> almost say I'll eat a PDP11!
Indeed. This one example seems utterly bizarre, and I suspect may be the only
instance of this sort of thing. "Soft vacuum" tubes doesn't sound very
sensible, though of course gas filled tubes are common (thyratrons and
ignitrons, not to mention mercury vapor filled rectifiers like the famous 866).
paul
