The Bell No.1 Electronic Switching System ( 1ESS ) is the first regularly used an agency for telecommunications, which worked purely programmed memory. 1ESS was taken in 1965 in Succasunna, NJ, United States for the first time in operation.
1ESS uses a redundant central processor in Harvard architecture. Telecommunications services can be flexibly programmed since then.
- Historical communication device
- Telephone network
- History of computer science