dekatron
decade counter tube

The dekatron fell out of practical use when transistor-based counters became reliable and affordable.

They have these bizarre things called "dekatron tubes."

A Dekatron is a cold-cathode tube with multiple electrodes that is used for counting.

A well-known trade name for glow-transfer counter tubes in the United Kingdom was Dekatron.

Internal designs vary by the model and manufacturer, but generally a dekatron has ten cathodes and one or two guide electrodes plus a common anode.

So these dekatron tubes - and you can look up "dekatron" on Wikipedia - they're actually decade, that is, 10 counting units.

The machine was decimal and initially had twenty 8-digit dekatron registers for internal storage, which was increased to 40 which appeared to be enough for nearly all calculations.

When a dekatron is first powered up, a glowing dot appears at a random cathode; the tube must then be reset to zero state, by driving a negative pulse into the designated starting cathode.

In electronics, a Dekatron (or Decatron, or generically three-phase gas counting tube or glow-transfer counting tube or cold cathode tube) is a gas-filled decade counting tube.

The Harwell computer, later known as the Wolverhampton Instrument for Teaching Computing from Harwell (WITCH), or the Harwell Dekatron Computer, was an early British relay-based computer.

"Dekatron," now a generic trademark, was the brand name used by the British Ericsson Telephones Limited (ETL), of Beeston, Nottingham (not to be confused with the Swedish TelefonAB Ericsson of Stockholm).

Low-power thyratrons (relay tubes and trigger tubes) were manufactured in the past for controlling incandescent lamps, electromechanical relays or solenoids, for bidirectional counters, to perform various functions in Dekatron calculators, for voltage treshold detectors in RC timers, etc.

The electronics division of the Atomic Energy Research Establishment at Harwell, UK built the Harwell Dekatron Computer in 1951, which was an automatic calculator where the decimal arithmetic and memory were electronic, although other functions were performed by relays.

The dekatron was useful for computing, calculating and frequency-dividing purposes because one complete revolution of the neon dot in a dekatron means 10 pulses on the guide electrode(s), and a signal can be derived from one of the ten cathodes in a dekatron to send a pulse, possibly for another counting stage.