The ZN414 is a low cost, single-chip AM radio integrated circuit. Launched in 1972, the part was designed and supplied by Ferranti, but was also available from GEC-Plessey. The ZN414 was popular amongst hobbyists as a fully working AM radio could be made with just a few external components, a crystal earpiece and a 1.5 V cell. The manufacturing process for the ZN414 chip used a relatively new (for the time) technique known as (CDI). CDI was invented by engineers at Bell Telephone Laboratories and subsequently developed into a commercial process by Ferranti in the UK.