Valve based computers

[Bigun]

I thought it was normal, at least for me! Like you described, I can’t seem to finish my projects but they are easy to start ..

 

[MarcelvdG]

I never built anything purely digital with valves, but I did build a mixed-signal circuit based on current steering valve logic. It is essentially a two-to-one multiplexer used as a two-tap FIRDAC. I use it as an audio digital to analogue converter.

 

[PRR]

I still have my slide rule...

(one of) Mine is on the shelf a foot above my hand.

Who needs valves?

Compute a Gunnery Table. XYZ-69 artillery cannon, 5 pound slug, angle of elevation in 1 degree increments, powder in whatever stock loads they give gunners. Compute range for each combination. Compute range for target at higher or lower altitude. Repeat for 7 pound load. Now invert all this data so the gunner goes in with his range and altitude needed, and gets a load and angle setting. Repeat again for the XYZ-70 cannon. And so on.

Obviously this "can" be done with slipstick and (paper) spreadsheet, and a large room of smart people who work cheap (students or women). But a room of tubes plus an electric typewriter does the same, a bit faster (after the construction) with fewer typos.

 

[Tubelab_com]

But a room of tubes plus an electric typewriter does the same, a bit faster

Ditto the daily ledger for a bank, department store, or even payroll for a good sized company. These tasks were best handled by say an IBM system 700. Unless you were a large company, these tasks were usually time shared on a leased mainframe.

The Motorola plant where I worked (5000 employees) had an IBM system 360 when I started there in 1973. It disappeared sometime in the 80's.