Doc, I can imagine!! (WARNING! TMI to follow!!) I have had several opportunities to visit Iowa State University in Ames. They have on display the Cyclone computer they built in 1959. The Cyclone has somewhere around 2,700 tubes. Over 1500 were 5844's used as switches. The Cyclone required a dedicated cooling system and was 10 feet tall, 12 feet long, 3 feet wide. The Cyclone used 19 Kw of electric power and weighed about 5,000 pounds. It had less computing power than a 1970's handheld programable calculator. The Cyclone was powered up about the same time IBM released a solid state computer. And the rest is history!!
DAC chips are typically pretty simple devices, especially R2R chips. I think the receiver chips are more complicated.
Cheers,
Geary