Abstract: A data processing display terminal utilizing a cathode ray tube (CRT) display is provided in which information-bearing electro-magnetic radiations are suppressed at the neck of the cathode ray tube and in the video circuits leading thereto, instead of mounting the entire display terminal in a shielded enclosure utilizing a piece of shielded glass over the CRT viewing area. A cylindrical shield is provided which completely encloses the socket and neck of the cathode ray tube, and extends to the proximity of the yoke of the CRT. A plurality of connectors are spaced about the cylindrical shield in the vicinity of the socket to accommodate connections to the socket. The video circuitry which carries the information desired to be displayed is completely shielded. The connectors in the cylindrical shield, with the exception of the video signal connector, are all provided with filters, and the video signal is coupled to the cylindrical shield connector by a shielded coaxial cable.

Abstract: A keyboard for use with a data processing display terminal utilizing a cathode ray tube (CRT) display is provided from which information bearing electromagnetic radiations are suppressed using solid state keyboard switches having no contact bounce and generating low level signals with few transients, metallic oxide silicon (MOS) semiconductor circuitry having relatively low switching speeds to generate few transients, careful packaging of components to minimize printed circuit path and wiring lengths, ferrite beads on component leads to suppress transient generation, and shielding of printed circuit paths by sandwiching them between ground planes.