Speaking of tubes in computers.... 1st Honeywell 1000 computer used some surprise tubes!

[ED SHARPE]

The H-800  was  pretty  modern compared  to the  1000!
I  marvel at  all of  them! Ed#
In a message dated 2/22/2022 11:27:10 PM US Mountain Standard Time, phil at regressive.org writes: 
There's a mention of the Datamatic 1000 in Hugh Blair-Smith's "Left
Brains for the Right Stuff" (on the development of the Apollo Guidance
Computer software), and gives an account that the B&O D-1000 got
flooded when a rooftop water tank burst, and hot tubes met cold water.

Early work on the AGC was hosted on the D-1000 descendent, the
Honeywell 800 series (replacing an IBM 650).  Blair-Smith describes
the H-800 as having eight execution contexts (sets of registers).